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Articles containing the keyword 'wood'

Category : Article

article id 5629, category Article
Risto Sievänen, Eero Nikinmaa, Jari Perttunen. (1997). Evaluation of importance of sapwood senescence on tree growth using the model Lignum. Silva Fennica vol. 31 no. 3 article id 5629. https://doi.org/10.14214/sf.a8531
Keywords: Pinus sylvestris; growth; growth model; pipe-model theory; sapwood senescence; open-grown trees
Abstract | View details | Full text in PDF | Author Info

The effects of two alternative formulations of sapwood senescence on the behaviour of model LIGNUM (with parameter values adjusted for Scots pine (Pinus sylvestris L.) growing southern Finland) were studied. The two alternatives were autonomous sapwood senescence assuming a maximum age for the tree ring, and sapwood senescence that is controlled by the mortality of foliage. For the latter alternative two hypothetical further mechanisms were stipulated. All the formulations were implemented in LIGNUM. Simulations were made with all model variants for fertile and poor soil conditions using high, normal and low rates of foliage mortality. The simulation results were compared against of a data set consisting of 11 open grown Scots pine trees from southern Finland. Observations of heartwood proportion were used in this study. They show that heartwood starts to increase in trees from age of approximately 20 years onwards. The simulation results showed no differences between fertile and poor soil conditions as regards heartwood formation. Of the variants of foliage-controlled sapwood senescence the one where death of sapwood in a tree segment induces sapwood senescence in the tree parts below only slightly was the best. This and the autonomous sapwood senescence corresponded equally well to the observations. In order to make more refined conclusions additional data and simulations are necessary.

  • Sievänen, E-mail: rs@mm.unknown (email)
  • Nikinmaa, E-mail: en@mm.unknown
  • Perttunen, E-mail: jp@mm.unknown
article id 5622, category Article
Christine Deleuze, François Houllier. (1997). A transport model for tree ring width. Silva Fennica vol. 31 no. 3 article id 5622. https://doi.org/10.14214/sf.a8523
Keywords: carbon; optimization; tree growth; stem taper; allocation; environment; wood distribution; functional balance; Münch’s theory; partitioning; process-model; reaction-diffusion; Thornley's model; silvicultural treatments
Abstract | View details | Full text in PDF | Author Info

Process-based tree growth models are recognized to be flexible tools which are valuable for investigating tree growth in relation to changing environment or silvicultural treatments. In the context of forestry, we address two key modelling problems: allocation of growth which determines total wood production, and distribution of wood along the stem which determines stem form and wood quality. Growth allocation and distribution are the outcome of carbon translocation, which may be described by the Munch theory. We propose a simpler gradient process to describe the carbon distribution in the phloem of conifers. This model is a reformulation of a carbon diffusion-like process proposed by Thornley in 1972. By taking into account the continuity of the cambium along the stem, we obtain a one-dimensional reaction-diffusion model which describes both growth allocation between foliage, stem and roots, and growth distribution along the stem. Distribution of wood along the stem is then regarded as an allocation process at a smaller scale. A preliminary sensitivity analysis is presented. The model predicts a strong relationship between morphology and foliage-root allocation. It also suggests how empirical data, such as stem analysis, could be used to calibrate and validate allocation rules in process-based growth models.

  • Deleuze, E-mail: cd@mm.unknown (email)
  • Houllier, E-mail: fh@mm.unknown
article id 5620, category Article
Anne Toppinen. (1997). Testing for Granger-causality in the Finnish roundwood market. Silva Fennica vol. 31 no. 2 article id 5620. https://doi.org/10.14214/sf.a8521
Keywords: roundwood market; forecasting; timber market; stumpage prices; statistical analysis; Granger-causality; time series analysis
Abstract | View details | Full text in PDF | Author Info

The existence and direction of causal relationships between the time series for the Finnish roundwood market for the period 1960–1994 is tested. Using simple bivariate analysis, we found evidence that for both logs and pulpwood, the lagged prices are helpful in forecasting quantity for the next year, but not vice versa. Saw log stumpage prices have significantly Granger-caused pulpwood prices over the business cycles, but the effect has diminished towards the present time. For quantities traded, the direction of causality was rather from pulpwood to saw logs. The consistency of bivariate test results was checked by the Granger-causality tests within trivariate VAR-models for both markets, and the results were found to be fairly similar to bivariate tests. The price fluctuations in the international markets for forest products have been found to be carried to domestic wood markets dominantly via the pulpwood part of the market.

  • Toppinen, E-mail: at@mm.unknown (email)
article id 5619, category Article
Pertti Harstela. (1997). Decision support systems in wood procurement. A review. Silva Fennica vol. 31 no. 2 article id 5619. https://doi.org/10.14214/sf.a8520
Keywords: decision making; decision support systems; planning; wood procurement
Abstract | View details | Full text in PDF | Author Info

Many kinds of planning systems have been labelled decision support systems (DSS), but few meet the most important features of real DSSs in planning and control of wood procurement. It has been concluded that many reasons exist to develop DSSs for wood procurement. The purchasing of timber seems to be one of the most promising areas for DSS, because there is no formal structure for these operations and decisions deal with human behaviour. Relations between DSSs and different features of the new approaches in wood procurement are also discussed, and hypotheses for future studies suggested.

  • Harstela, E-mail: ph@mm.unknown (email)
article id 5617, category Article
Teijo Palander. (1997). A local DLP-GIS-LP system for geographically decentralized wood procurement planning and decision making. Silva Fennica vol. 31 no. 2 article id 5617. https://doi.org/10.14214/sf.a8518
Keywords: Finland; GIS; linear programming; dynamic linear programming; DLP; geographical decentralization; local wood procurement; participatory planning; wood procurement
Abstract | View details | Full text in PDF | Author Info

Linear programming (LP) is an important method for allocation of wood inventory stock. It is, for instance, used alone in tactical planning systems, which currently are in wide use at the higher hierarchical level in the functionally decentralized planning of the Finnish forest industry. Unfortunately, LP as a solution method has not been capable of handling spatial data that seem to characterize planning systems in geographical decentralization. In the present study, GIS was used to assimilate data from different wood procurement functions, to calculate transportation distances and cost figures, and to write the data in ASCII files, which were then used as input for the LP model. Using the experiments and methods of GIS on a planning system developed according to participatory planning, the results of this study suggest that the participatory method was faster than the conventional LP method, when solved using actual data. The participatory method was also capable of providing the same global optimum for a wood allocation problem. The implications of these results for improving operational and tactical planning of wood procurement in Finland are discussed.

  • Palander, E-mail: tp@mm.unknown (email)
article id 5614, category Article
Mika Jääskelä, Kari Heliövaara, Mikko Peltonen, Hannu Saarenmaa. (1997). Comparison of protection methods of pine stacks against Tomicus piniperda. Silva Fennica vol. 31 no. 2 article id 5614. https://doi.org/10.14214/sf.a8515
Keywords: forest protection; GIS; Tomicus piniperda; timber storage; insect pests; road side landings of timber; pulpwood stacks; protection of timber
Abstract | View details | Full text in PDF | Author Info

Three most promising protection methods of pine pulp wood stacks against the attacks of Tomicus piniperda L. were compared. The methods were the covering of stacks by fibreglass-strengthened paper or twofold achrylene netting, removing the upper parts of stacks, and enhanced planning of the placement of the timber store using ARC/INFO GIS-software. T. piniperda was observed to strongly prefer the upper parts of the stacks: 90 % of the beetles occurred within 0.5 meters of the top of the stacks. Covering of the stacks decreased the attack density of T. piniperda, and the protection effect of covering was 80 %. Due to long transport distances and fragmentation of forest landscape the relocation of timber store was found to be an unsuitable method in the practical level. Also, taking into account the costs of the method, removing of the upper parts of stacks was considered to be the optimal solution.

  • Jääskelä, E-mail: mj@mm.unknown (email)
  • Heliövaara, E-mail: kh@mm.unknown
  • Peltonen, E-mail: mp@mm.unknown
  • Saarenmaa, E-mail: hs@mm.unknown
article id 5605, category Article
Matti Haapanen, Marja-Leena Annala, Pirkko Velling. (1997). Progeny trial estimates of genetic parameters for growth and quality traits in Scots pine. Silva Fennica vol. 31 no. 1 article id 5605. https://doi.org/10.14214/sf.a8506
Keywords: Pinus sylvestris; Scots pine; wood quality; genetic correlation; heritability; progeny testing
Abstract | View details | Full text in PDF | Author Info

Estimates of individual heritability and genetic correlation are presented for a set of 10 growth and quality traits based on data from 16 Scots pine (Pinus sylvestris L.) progeny trials in Finland. Seven of the traits (tree height, stem diameter, crown width, Pilodyn value, branch diameter, branch angle and branch number) were objectively measured, whereas three traits (stem straightness, branching score and overall score) were assessed visually. The genetic correlations were mostly moderate or low, and favourable from the tree breeder's point of view. All variables related to tree size correlated relatively strongly and positively. Tree height exhibited a more favourable genetic relationship with the crown form traits than diameter, the latter showing positive correlation with branch diameter. Except for the slight negative correlation between branch angle and branch diameter, the branching traits were not notably correlated. The pilodyn value was positively correlated with stem diameter, reflecting negative correlation between diameter growth and wood density. The highest genetic correlations occurred among the two visually evaluated quality scores and branch diameter. All of the heritabilities were less than 0.4. Overall score, Pilodyn, branch angle, branching score and tree height showed the highest heritability.

  • Haapanen, E-mail: mh@mm.unknown (email)
  • Annala, E-mail: ma@mm.unknown
  • Velling, E-mail: pv@mm.unknown
article id 5566, category Article
Reijo Penttilä, Heikki Kotiranta. (1996). Short-term effects of prescribed burning on wood-rotting fungi. Silva Fennica vol. 30 no. 4 article id 5566. https://doi.org/10.14214/sf.a8501
Keywords: boreal forests; forest fires; Picea abies; polypores; controlled burning; wood decay; wood-rotting fungi; corticoid fungi; fungal community structure
Abstract | View details | Full text in PDF | Author Info

The prefire fungal flora (polypores and corticoid fungi) of 284 dead trees, mainly fallen trunks of Norway spruce (Picea abies (L.) H. Karst.), was studied in 1991 in an old, spruce-dominated mesic forest in Southern Finland. Species diversity of the prefire fungal flora was very high, including a high proportion of locally rare species and four threatened polypore species in Finland.

In 1992 part of the study area (7.3 ha) was clear-cut and a 1.7 ha forest stand in the centre of study area was left standing with a tree volume of 150 m3/ha, and later on (June 1st) in the same year the whole area was burned. Burning was very efficient and all trees in the forest stand were dead one year after the fire. Also, the ground layer burned almost completely.

In 1993 the fungal flora of the 284 sample trees was studied again. Most of the trees had burned strongly and the fungal species diversity and the evenness in community structure had decreased considerably as compared with the prefire community. Species turnover was also great, especially in corticoid fungi. Greatest losses in the species numbers occurred in moderately and strongly decayed trees, in coniferous trees and in very strongly burned trees. Fungal flora of non-decayed and slightly decayed trees, deciduous trees and slightly burned trees seemed to have survived the fire quite well, and in these groups the species numbers had increased slightly as compared with the prefire community.

Fungal species suffering from fire (anthracophobe species) were mainly growing in moderately and strongly decayed trees before the fire, whereas species favoured by fire (anthracophile species) were growing in less decayed trees. No fruitbodies of threatened polypores or other "old-forest species" of polypores were found again after fire. Some very common and effective wood-rotting fungi (e.g. Fomitopsis pinicola, Fomes fomentarius, Antrodia serialis) survived the fire quite well (anthracoxene species). Species favoured by fire were mainly ruderal species which can utilize new, competition-free resources created by fire, and species that have their optima in dry and open places also outside forest-fire areas. Some rarities, e.g. Phanerochaete raduloides and Physisporinus rivulosus, were favoured by fire.

  • Penttilä, E-mail: rp@mm.unknown (email)
  • Kotiranta, E-mail: hk@mm.unknown
article id 5592, category Article
Ari Talkkari. (1996). Regional predictions concerning the effects of climate change on forests in southern Finland. Silva Fennica vol. 30 no. 2–3 article id 5592. https://doi.org/10.14214/sf.a9237
Keywords: climate change; Finland; simulation; growing stock; wood production; Gap model; regional predictions; cutting yield
Abstract | View details | Full text in PDF | Author Info

A gap-model was used with forest inventory data in taking ground-true site, soil and tree characteristics into account in predicting the effects of climate change on forests. A total of 910 permanent sample plots established in the course of national forest inventory (NFI) in Finland and located on mineral soil sites in southern Finland were selected as the input data. The climatological input used in the simulations consisted of interpolated means of and deviations from long-term local temperature and precipitation records. The policy-oriented climate scenarios of SILMU (Finnish Research Programme on Climate Change) were used to describe the climate change. The temperature changes in the climate scenarios were increases of ca. +1.1 °C (low), +4.4 °C (medium) and +6.6 °C (high) compared to the current climate in 110 years. The simulation period was 110 years covering the time years 1990–2100.

Southern Finland, divided into fifteen forestry board districts, was used as the study region. Regional development of stand volume, cutting yield, and total wood production of forests under different climate scenarios were examined. The annual average growth in simulations under current climate was close to that observed in NFL Forests benefited from a modest temperature increase (Scenario 2), but under Scenario 1 the growing stock remained at a lower level than under the current climate in all parts of the study region. In wood production and cutting yield there were regional differences. In the southern part of the study regional wood production under Scenario 1 was ca. 10% lower than under the current climate, but in the eastern and western parts wood production was 5–15% higher under Scenario 1 than under the current climate. The relative values of total wood production and cutting yield indicated that the response of forests to climate change varied by geographical location and the magnitude of climate change. This may be a consequence of not just varying climatic (e.g. temperature and precipitation) and site conditions, but of varying responses by different kind of forests (e.g. forests differing in tree species composition and age).

  • Talkkari, E-mail: at@mm.unknown (email)
article id 5576, category Article
Matti Nuorteva, Lennart Saari. (1996). Winter ecology of a female White-backed Woodpecker Dendrocopos leucotos (Bechstein). Silva Fennica vol. 30 no. 1 article id 5576. https://doi.org/10.14214/sf.a9221
Keywords: winter food; Dendrocopos leucotos; white-backed woodpecker; prey insects; sawflies
Abstract | View details | Full text in PDF | Author Info

In the winter of 1977/78, a White-backed Woodpecker (Dendrocopos leucotos Bechstein) was observed in the archipelago of southwestern Finland 200 km from its breeding areas. It foraged on insects living in mall dead alder and birches. The potential prey species were identified by rearing the insects from the trunks used by the White-backed Woodpecker. Altogether 628 adult insects emerged. In addition to the big larvae the potential food also included larvae of Sciaridae and Cecidomyidae (Diptera) living in dense clumps.

  • Nuorteva, E-mail: mn@mm.unknown (email)
  • Saari, E-mail: ls@mm.unknown
article id 5550, category Article
Jyrki Hytönen. (1995). Effect of repeated fertilizer application on the nutrient status and biomass production of Salix ’Aquatica’ plantations on cut-away peatland areas. Silva Fennica vol. 29 no. 2 article id 5550. https://doi.org/10.14214/sf.a9201
Keywords: biomass production; fertilization; fuelwood; peatlands; short-rotation forestry; Salix 'Aquatica'
Abstract | View details | Full text in PDF | Author Info

The effects of repeated fertilizer treatment on biomass production and nutrient status of willow (Salix ’Aquatica’) plantations established on two cut-away peatland areas in western Finland were studied over a rotation period of three years. Comparisons were made between single fertilizer applications and repeated annual fertilization.

The annually repeated fertilizer application increased the amounts of acid ammonium acetate extractable phosphorus and potassium in the soil as well as the concentrations of foliar nitrogen, phosphorus and potassium compared to single application. Depending on the fertilizer treatment and application rate, annual fertilizer application resulted in over two times higher biomass production when compared to single fertilizer application over a three-year rotation period. The effect of phosphorus fertilizer application lasted longer than that of nitrogen. The optimum fertilization regime for biomass production requires that nitrogen fertilizer should be applied annually, but the effect of phosphorus can last at least over a rotation of three years. Potassium fertilizer treatment did not increase the yield in any of the experiments during the first three years. The leafless, above-ground yield of three-year-old, annually NP-fertilized willow plantations was 9.5 t ha-1 and the total biomass, including stems, leaves, roots and the stump, averaged 17 t ha-1.

  • Hytönen, E-mail: jh@mm.unknown (email)
article id 5544, category Article
Jyrki Hytönen. (1995). Effect of fertilizer treatment on the biomass production and nutrient uptake of short-rotation willow on cut-away peatlands. Silva Fennica vol. 29 no. 1 article id 5544. https://doi.org/10.14214/sf.a9195
Keywords: biomass production; fertilization; fuelwood; nutrients; peatlands; short-rotation forestry; Salix; consumption
Abstract | View details | Full text in PDF | Author Info

The effects of fertilized treatment on the soil nutrient concentrations, biomass production and nutrient consumption of Salix x dasyclados and Salix ’Aquatica’ were studied in five experiments on three cut-away peatland sites in western and eastern Finland during three years. Factorial experiments with all combinations of N (100 kg ha-1 a-1), P (30 kg ha-1 a-1) and K (80 kg ha-1 a-1) were conducted.

The application of P and K fertilizers increased the concentrations of corresponding extractable nutrients in the soil as well as in willow foliage. N-fertilization increased foliar nitrogen concentration. An increase in age usually led to decreases in bark and wood N, P and K concentrations and increases in bark Ca concentrations. N-fertilization increased the three-year biomass yield 1.5–2.7 times when compared to control plots. P-fertilization increased the yield only in those experimental fields whose substrates had the lowest phosphorus concentration. K-fertilization did not increase the yield in any of the experimental fields. The highest total biomass yield of NPK-fertilized willow after three growing seasons, 23 t ha-1, was distributed in the following way: wood 42%, bark 19%, foliage 17%, stumps 6% and roots 16%. As the yield and stand age increased, more biomass was allocated in above-ground wood. Three-year-old stands (above-ground biomass 18 t ha-1) contained as much as 196 kg N ha-1, 26 kg P ha-1, 101 kg K ha-1, 74 kg Ca ha-1 and 37 kg Mg ha -1. By far the highest proportion of nutrients accumulated in the foliage. The bark and wood contained relatively high proportions of calcium and phosphorus. With an increase in age and size, the amount of nitrogen and potassium bound in one dry-mass ton of willow biomass decreased while that of phosphorus remained unchanged.

  • Hytönen, E-mail: jh@mm.unknown (email)
article id 5540, category Article
Anders Persson. (1994). How genotype and silviculture interact in forming timber properties. Silva Fennica vol. 28 no. 4 article id 5540. https://doi.org/10.14214/sf.a9180
Keywords: Pinus sylvestris; Picea abies; silviculture; wood properties; spacing; genotypes
Abstract | View details | Full text in PDF | Author Info

Independent of genotype, increased spacing results in increased branch diameter of Scots pine (Pinus sylvestris L.), but on different levels for different genotypes. Frequency of defects like spike knots and crooked stems are under stronger genetic than silvicultural control. Simultaneous improvement of rate of growth and timber properties is feasible. Deteriorating of both factors can happen rapidly at a negative selection. A defect like stem cracking of Norway spruce (Picea abies (L.) H. Karst.) only manifests itself under drought stress when certain genetic and environmental prerequisites are present, like high fertility and wide spacing. This emphasize the fact that new silvicultural methods may reveal genetic weaknesses.

  • Persson, E-mail: ap@mm.unknown (email)
article id 5532, category Article
Anu Honkanen. (1994). Selection of Salix myrsinifolia clones for biomass forestry in Finland. Silva Fennica vol. 28 no. 3 article id 5532. https://doi.org/10.14214/sf.a9172
Keywords: biomass; selection; diameter distribution; short rotation forestry; fuelwood; production; clones; Salix phylicifolia; Salix myrsinifolia
Abstract | View details | Full text in PDF | Author Info

For biomass forestry in the inland parts of Southern and Central Finland, the obvious choice of willow species is Salix myrsinifolia. However, selection of clones of indigenous species has not yet been completed and more research and selection is needed. In the Piipsanneva old peatland trial, indigenous species of willow, mostly clones of S. myrsinifolia and S. phylicifolia, were compared in terms of biomass production, coppicing, height growth and diameter distributions. In this trial, the mean annual biomass production was not particularly high; more important results were attained in the ranking of clones. The trial strengthens the hypothesis that, over the long-term, the biomass production of S. myrsinifolia is higher than that of S. phylicifolia. It was supposed that behind the highest yield there was a clone with uniform quality, one whose diameter distribution would be narrow and positively skewed. Comparisons of parameters of Weibull functions showed that the distributions of the best clones were wide, indicating that those clones use the whole growth space better than those with narrow distribution.

  • Honkanen, E-mail: ah@mm.unknown (email)
article id 5531, category Article
Anneli Viherä-Aarnio, Anna Saarsalmi. (1994). Growth and nutrition of willow clones. Silva Fennica vol. 28 no. 3 article id 5531. https://doi.org/10.14214/sf.a9171
Keywords: biomass; short rotation forestry; fuelwood; nutrients; clones; hybridization; Salix
Abstract | View details | Full text in PDF | Author Info

Growth and nutrition of 20 clones representing different species and interspecific hybrids of willows (Salix spp.) growing on an abandoned field were studied. There were highly significant differences between the clones as regards the survival, number of sprouts per stool, sprout mean height and diameter and stem biomass production per stool. The differences between the clones in the concentration of all nutrients in both the leaves and stems were highly significant. 

  • Viherä-Aarnio, E-mail: av@mm.unknown (email)
  • Saarsalmi, E-mail: as@mm.unknown
article id 5398, category Article
Timo Karjalainen, Seppo Kellomäki, Ari Pussinen. (1994). Role of wood-based products in absorbing atmospheric carbon. Silva Fennica vol. 28 no. 2 article id 5398. https://doi.org/10.14214/sf.a9163
Keywords: wood products; Finland; carbon balance; timber; lifespan
Abstract | View details | Full text in PDF | Author Info

The amount of carbon (C) stored in wood products manufactured in Finland was calculated with the help of a model using wood harvesting statistics, product flows and lifespans in order to study how much C could be set aside from the atmospheric C cycle outside the forest ecosystem. The calculations showed that on the average 9.9 Tg C/a was in harvested timber in 1986–1991 in Finland. C emissions of timber harvest and transport were 0.1 Tg C/a. In production processes about one third of the C bound in in timber was released into the atmosphere, but two thirds was still bound in products. After 50 and 100 years, more than 40% and 33% of the C initially in products was either in products still in use or disposed to landfills. The wood product C storage was most sensitive to landfill decay rate and to the burning of abandoned products for energy, but not to the same extent to the length of the lifespan of products.

  • Karjalainen, E-mail: tk@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
  • Pussinen, E-mail: ap@mm.unknown
article id 5522, category Article
Jari Kokkola. (1993). Drying of pulpwood in northern Finland. Silva Fennica vol. 27 no. 4 article id 5522. https://doi.org/10.14214/sf.a15683
Keywords: pulpwood; storage; moisture; green weight; storage weight loss
Abstract | View details | Full text in PDF | Author Info

Drying of pulpwood bolts of Scots pine (Pinus sylvestris L.), birch (Betula spp.) and Norway spruce (Picea abies (L.) H. Karst.) was studied by measuring the drying of sample bolts placed in experimental piles. The results revealed that the main factors affecting timber drying are debarked surface area, moisture content at the time of felling and the size of the bolt. Furthermore, pine and spruce bolts located in the upper part of the pile dry better than bolts near the ground.

The investigation of green weight changes of whole piles of pine and birch was based on data collected in 1987–91. The green weight of piles was dependent mainly on storage time and on region; effect of weather variables could not be distinguished. Specific calibrating coefficients for motor-manual and mechanical cutting were included in the green weight equations.

Comparison between green weight equations and detected weight losses of sample piles indicates that fitted models seem to produce at least approximate results for the green weights, the said results thus lending themselves to be utilized as part of a transportation cost model.

The PDF includes an abstract in Finnish.

  • Kokkola, E-mail: jk@mm.unknown (email)
article id 5512, category Article
Christian Messier, Pasi Puttonen. (1993). Coniferous and non-coniferous fine-root and rhizome production in Scots pine stands using the ingrowth bag method. Silva Fennica vol. 27 no. 3 article id 5512. https://doi.org/10.14214/sf.a15673
Keywords: Pinus sylvestris; ground vegetation; undergrowth; roots; root systems; fine-root production; ingrowth bag; rhizomes; underwood
Abstract | View details | Full text in PDF | Author Info

Coniferous and non-coniferous fine root and rhizome production was measured after one growing season using the ingrowth bag method in Scots pine (Pinus sylvestris L.) stands differing in ages from 7 to 105 years in Southern Finland. Total fine-root production decreased from the 7-year to 20-year-old stands, and then increased slightly in the 85- to 105-year-old stands. Most of the total fine-root biomass in the youngest age groups came from non-conifer species, whereas most of the total fine-root biomass in the three older age groups came from conifer species. The maximum coniferous fine-root production was found to occur at crown closure in the 11- to 13-year-old stands. Rhizome production was the lowest and highest in the 20- and 85- to 105-year-old stands, respectively. The increase in rhizome production in the 85- to 105-year-old stands was associated with an abundant understory cover of Vaccinium myrtillus and V. vitis-idaea and an increase in light penetration. The ingrowth bag method was found to be useful in assessing the relative fine-root production among species-group and successional stages of Scots pine stands.

The PDF includes an abstract in Finnish.

  • Messier, E-mail: cm@mm.unknown (email)
  • Puttonen, E-mail: pp@mm.unknown
article id 5483, category Article
Erkki Verkasalo. (1992). Relationships of the modulus of elasticity and the structure of Finnish Scots pine wood. Silva Fennica vol. 26 no. 3 article id 5483. https://doi.org/10.14214/sf.a15644
Keywords: Pinus sylvestris; wood properties; wood anatomy; wood structure; tracheids; modulus of elascticity; stereology
Abstract | View details | Full text in PDF | Author Info

The paper presents preliminary results on the relationships of the longitudinal modulus of elasticity (E) in bending, based on ISO Standard 3349 tests on small, clear specimens, and some basic characteristics of Finnish Scots pine (Pinus sylvestris L.) wood. A manual image analysis method – quantitative stereological counting – was introduced and applied for the investigations of wood structure.

The main results were consistent with those from the prior research. The range of E was 9.7 to 19.1 GPa. Increase in especially fibre density index (R2 = 0.95), weight density and specific gravity (R2 = 0.90), Runkel’s ratio, coefficient of cell rigidity and number of growth rings per cross-sectional unit area, but also in latewood percentage (R2 = 0.58) resulted in an increase in E. Increase in growth ring width, particularly in the width of the late wood section within a ring (R2 = 0.63 to 0.90) had a reverse effect. Cell wall thickness did not show any clear effect. Except for tracheid diameter, the relationships were stronger for the variables determined in the tangential than in the radial wood direction.

Quantitative stereological counting has been used to some degree in the Finnish wood research. The procedure is technically feasible and easy to use. A large sample of counting areas is frequently needed to obtain accurate mean results for the size and distribution of the features. Because the actual analysis points are located at a fixed distance from each other, the method is not in principle well suited for wood with a regular and simple structure, as Scots pine. However, the good correlations between E and some characteristics obtained with stereological counting did not support this misgiving.

The PDF includes an abstract in Finnish.

  • Verkasalo, E-mail: ev@mm.unknown (email)
article id 5480, category Article
Erkki Verkasalo. (1992). Forest industry as a producer and consumer of wood-based energy in Finland. Silva Fennica vol. 26 no. 2 article id 5480. https://doi.org/10.14214/sf.a15641
Keywords: Finland; fuelwood; fuels; forest products industries; wood residues; black liquor; calorific value
Abstract | View details | Full text in PDF | Author Info

This article summarises the importance of forest industry in the acquisition and consumption of wood-based energy in Finland. Opportunities to increase the efficiency of energy utilization further are discussed, as well.

The forest industry uses 25% of the total energy and 40% of the total electricity. It also generates considerable amounts of heat and electric power as by-products of wood-processing. Wood in different forms accounts for 64% of the fuels of the forest industry. Consequently, the need for outside, imported energy is minute. Black liquor of pulping is dominant as a source of wood-based energy. In addition, plenty of wood residues (bark, saw dust, planer shavings, grinder dust, screening reject of chips) and minor amounts of for wood processing unsuitable fractions obtained in conjunction with harvesting small-sized whole-trees, tree selections and logging residues are used for energy production.

The PDF includes an abstract in Finnish.

  • Verkasalo, E-mail: ev@mm.unknown (email)
article id 5459, category Article
Pertti Pulkkinen. (1991). Crown form and harvest increment in pendulous Norway spruce. Silva Fennica vol. 25 no. 4 article id 5459. https://doi.org/10.14214/sf.a15617
Keywords: biomass production; allocation; needle biomass; crown; stem; Picea abies f. pendula; branchwood biomass
Abstract | View details | Full text in PDF | Author Info

Crown characteristics and the distribution of three years’ (1986–88) biomass production of 20 pendulous Norway spruce (Picea abies f. pendula (Lawson) Sylvén) trees with heritable narrow crown and 15 normal-growned spruces (Picea abies (L.) H. Karst.) were studied in a 19-year-old mixed stand.

The form of the crown is conical in normal-crowned trees, columnar and narrow in pendulous trees. The partitioning of aboveground biomass to stems during the studied 3-year period was significantly higher in pendulous (0.281) than in normal-crowned trees (0.255) and also the ratio between growth of stemwood and growth of needle biomass during three years was higher in pendulous trees (0.67 g g-1) than in normal-crowned trees (0.52 g g-1). The needle biomass was distributed higher in the crown in pendula than in normal-crowned trees and they had a higher needle biomass/branchwood biomass ratio than normal trees. The difference in harvest increment between the two crown types are mostly due to the significantly lower branchwood biomass values in pendulous than in normal-crowned trees. The higher needle ’efficiency’ in pendulous trees is probably connected with high partitioning of needle biomass to the upper part of the crown in pendulous trees.

The PDF includes an abstract in Finnish.

  • Pulkkinen, E-mail: pp@mm.unknown (email)
article id 5447, category Article
Jyrki Tomminen. (1991). Pinewood nematode, Bursaphelenchus xylophilus, found in packing case wood. Silva Fennica vol. 25 no. 2 article id 5447. https://doi.org/10.14214/sf.a15601
Keywords: sawn wood; Bursaphelenchus xylophilus; pinewood nematode; packing wood; imported wooden packaging
Abstract | View details | Full text in PDF | Author Info

Living third dispersal stage juveniles of pinewood nematode, Bursaphelenchus xylophilus, were found infesting pine boards in Finland. The boards had been used as building material in a packing case to hold imported machinery. Total numbers of nematodes extracted from the boards did not exceed 4 grams of dry wood. When cultured on Botrytis cinerea the nematode reproduction resumed rapidly.

The PDF includes an abstract in Finnish.

  • Tomminen, E-mail: jt@mm.unknown (email)
article id 5424, category Article
Timo Pukkala, Veli Pohjonen. (1990). Use of linear programming in land use planning in the Ethiopian highlands. Silva Fennica vol. 24 no. 2 article id 5424. https://doi.org/10.14214/sf.a15578
Keywords: plantations; fuelwood; mathematical models; grazing; Eucalyptus globulus; arable crops
Abstract | View details | Full text in PDF | Author Info

Linear programming was used to analyse the land use alternatives in the Debre Birhan Fuelwood Plantation area, in the central highlands of Ethiopia. The region represents a rural, high-altitude area, where the main land uses are grazing and cultivation of barley, wheat and pulses. To alleviate fuelwood shortage, large plantations of Eucalyptus globulus Labill. have been established. Livestock has traditionally used the major part of the production capacity of the sites. A decrease in the number of cattle would facilitate a considerable increase in the production of cereals, pulses, fuelwood and construction timber. The optimal share of the land for arable crops, grazing and tree plantations would be about 40, 45 and 15% respectively.

The PDF includes an abstract in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
  • Pohjonen, E-mail: vp@mm.unknown
article id 5422, category Article
Viljo Holopainen. (1990). Suomen pyöreän puun vienti 1921-1986. Silva Fennica vol. 24 no. 2 article id 5422. https://doi.org/10.14214/sf.a15576
English title: Finnish exports of roundwood in 1921–1986.
Original keywords: puutavara; vienti; Suomi; markkinointi; raakapuun vienti; 1900-luku; vientipolitiikka
English keywords: Finland; roundwood; export; marketing; export policy
Abstract | View details | Full text in PDF | Author Info

When Finland attained independence in 1917–1918, about 65% of her population made their linving from agriculture and only 17% from industry. Despite the fact that most sectors of the modern forest industry, i.e. sawmilling, pulp and paper making as well as plywood industry were then in existence a considerable proportion of timber was exported as roundwood.

It was reasonable to assume, however, that further economic development would reduce the roundwood exports to provide raw material for industry. The present paper investigates the Finnish roundwood exports in 1921–1986 largely from the point of view of this hypothesis. Examination of statistics is focused on the change of volume of exports in the major categories of wood, changes in the trade policies of consumer countries, changes in competition between exporting countries and changes in Finnish export policy.

The PDF includes an abstract in English.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 5389, category Article
Jyrki Tomminen, Matti Nuorteva, Markku Pulkkinen, Jouni Väkevä. (1989). Occurrence of the nematode Bursaphelenchus mucronatus Mamiya & Enda 1979 (Nematoda: Aphelenchoididae) in Finland. Silva Fennica vol. 23 no. 4 article id 5389. https://doi.org/10.14214/sf.a15547
Keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; Finland; wood; Bursaphelenchua xylophilus; Bursaphelenchus mucronatus; nematodes; Monochamus galloprovincialis; Monochamus sutor
Abstract | View details | Full text in PDF | Author Info

A survey was conducted in Finland in 1988 to determine whether the pine wood nematode Bursaphelenchus mucronatus Mamiya & Enda 1979 (Nematoda: Aphelenchoididae) or the closely related species B. mucronatus would occur in Finnish forests. Dead or dying standing trees and timber of two conicer species, Pinus sylvestris L. (Scots pine) and Picea abies (L.) H. Karst. (Norway spruce) were analysed for the presence of these nematodes. Monochamus spp. pine sawyers (Coleoptera: Cerambycidae) were also collected and inspected for the presence of dispersal fourth juvenile stages (dauerlarva) of the nematodes. The species B. xylophilus was not found, but B. mucronatus appeared to be widespread in the country. Individuals of this nematode were found both from Scots pine and Norway spruce. Adults of two Monochamus species were found, M. galloprovincialis and M. sutor. Only two of the examined beetles of the former species had dauerlarvae in their body.

The PDF includes an abstract in Finnish.

  • Tomminen, E-mail: jt@mm.unknown (email)
  • Nuorteva, E-mail: mn@mm.unknown
  • Pulkkinen, E-mail: mp@mm.unknown
  • Väkevä, E-mail: jv@mm.unknown
article id 5388, category Article
Martti Varmola. (1989). Männyn istutustaimikoiden lustonleveysmalli. Silva Fennica vol. 23 no. 4 article id 5388. https://doi.org/10.14214/sf.a15546
English title: A model for ring width of planted Scots pine.
Original keywords: mänty; taimikot; lustonleveys; kasvumallit; puuaineen laatu
English keywords: Pinus sylvestris; wood quality; spacing; ring width; growth models
Abstract | View details | Full text in PDF | Author Info

Ring width at breast height is presented as a function of stem radius at breast height, the ratio between the diameter of a tree and the basal area median diameter, site index, and density of stand. By means of a conversion model ring width at stump height can be estimated as a function of ring width at breast height.

According to previous studies substantially better wood quality can be expected if mean width near the pith at stump height decreases from 3 to 2 mm. According to the present study only on the poorest sites suitable for Scots pine (Pinus sylvestris L.) planting (poor Vaccinium type) the ring width is less than 3 mm at stump height even in the thickest trees. On more fertile sites a substantial increase in the recommended planting density is required, if the mean ring width is aimed to be less than 3 mm. On the best sites it is impossible to reach mean ring width of less than 2 mm, when the density is less than 4,000 stems/ha. Only the thinnest trees on the poorest sites can have a mean ring width less than 2mm.

The PDF includes an abstract in English.

  • Varmola, E-mail: mv@mm.unknown (email)
article id 5371, category Article
Riitta Laurila. (1989). Pieniläpimittaisen männyn kuituominaisuudet. Silva Fennica vol. 23 no. 1 article id 5371. https://doi.org/10.14214/sf.a15530
English title: Fibre properties in Pinus sylvestris pulpwood.
Original keywords: kuitupuu; pienpuu; mänty; trakeidit; puuaineen ominaisuudet; kuitujen pituus; soluseinän paksuus
English keywords: Pinus sylvestris; cell wall thickness; wood properties; pulpwood; small-sized stems; tracheid length; smallwood
Abstract | View details | Full text in PDF | Author Info

Properties of fibres in pulpwood, especially length, width and the thickness of walls in tracheids, are essential for strength properties of pulp and paper. Length and width of tracheids increase from pith to surface in radial direction. Young and small-sized stems have also smaller fibres. Small-sized Pinus sylvestris L. test trees had tracheids that were shorter both in stems and knot wood than those in normal sized trees. However, cell walls in test trees were as thick as in normal sized trees. It seems that especially the L/T -ratio (length/thickness) in small stems is worse than in normal sized pulp wood.

The PDF includes an abstract in English.

  • Laurila, E-mail: rl@mm.unknown (email)
article id 5312, category Article
Timo Pukkala. (1987). Siementuotannon vaikutus kuusen ja männyn vuotuiseen kasvuun. Silva Fennica vol. 21 no. 2 article id 5312. https://doi.org/10.14214/sf.a15469
English title: Effect of seed production on the annual growth of Picea abies and Pinus sylvestris.
Original keywords: kuusi; mänty; Lappi; siemensato; sädekasvu; kesäpuu
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; Finland; latewood; Lapland; radial growth; seed crop
Abstract | View details | Full text in PDF | Author Info

The study material consisted of 13 rather old Norway spruce (Picea abies (L.) H. Karst.) and 17 Scots pine (Pinus sylvestris L.) stands located in different parts of Finland. In each stand the seed crops, radial growth and amount of latewood were measured during a period of about ten years. Seed production reduces the radial growth of spruce and pine in the year of seed maturing. In Southern and Central Finland also the proportion of latewood is reduced. Seed production accounts for about 14% of the variation in radial growth of a spruce stand growing in Lapland, and 27% in other parts of Finland. In pine stands the seed crop explains 19% of the variation in radial growth in Lapland, and only 7% in the rest of Finland. In spruce stands an average seed crop reduces radial growth by 14% in Lapland and 5% in the rest of the country. An abundant seed production causes a reduction of about 20%. In southern parts of Finland, the proportion of latewood is reduced by 5% in an average seed year and by 24% in a good seed year. In pine stands an average seed crop decreases the width of annual ring by 5%, and a good seed crop by 15%. Outside Lapland, also the proportion of latewood is reduced: in an average seed year by 5%, and in a good seed year by 16%. The reduction in volume growth of spruce stands due to an average seed crop was estimated to be about 10% in Lapland, and 6% in other parts of Finland. A prolific seed production causes a reduction of 20%. In old pine stands the reduction is 5% in an average seed year, and 15% in a good seed year.

The PDF includes an abstract in English.

  • Pukkala, E-mail: tp@mm.unknown (email)
article id 5310, category Article
Petri Kärenlampi. (1987). Puun lahonkestävyys ja kosteusdynamiikka. Silva Fennica vol. 21 no. 2 article id 5310. https://doi.org/10.14214/sf.a15467
English title: The decay resistance and moisture dynamics of wood.
Original keywords: puulajit; kosteus; sydänpuu; puuaines; lahonkestävyys; mantopuu
English keywords: Pinus sylvestris; Picea abies; sapwood; tree species; heartwood; decay resistance; moisture
Abstract | View details | Full text in PDF | Author Info

In laboratory studies the heartwood content seems to be the only natural property of a wood of different tree species influencing the decay resistance. Moistening and drying by diffusion happen quite slowly. Scots pine (Pinus sylvestris L.) sapwood takes moisture by capillary action quicker than pine heartwood and Norway spruce (Picea abies (L.) H. Karst.) wood. Swelling and shrinkage are also greatest in pine sapwood. Impregnation of pine sapwood can give it better hydrophobic and dimensional stability than that of pine heartwood.

The PDF includes an abstract in English.

  • Kärenlampi, E-mail: pk@mm.unknown (email)
article id 5293, category Article
Claude Gendreau. (1986). Historical considerations and evolution of the forest policies for small woodlot owners of Quebec. Silva Fennica vol. 20 no. 4 article id 5293. https://doi.org/10.14214/sf.a27749
Keywords: forest management; forest policy; Canada; non-industrial forest owners; private forestry; forest programs; timber marketing; small-woodlot forestry
Abstract | View details | Full text in PDF | Author Info

In order to understand the present forest policies for the small woodlot of Quebec, it is essential to understand the history of settlement of Quebec. Following this brief description, the author introduces the various forest policies (programs) which have been initiated in Quebec by various levels of governments in order to deal with the management of these lands.

  • Gendreau, E-mail: cg@mm.unknown (email)
article id 5277, category Article
Kirsi Maasalo. (1986). Pihlajan puuaineen ominaisuuksia. Silva Fennica vol. 20 no. 3 article id 5277. https://doi.org/10.14214/sf.a15456
English title: Properties of the wood of the rowan tree (Sorbus aucuparia).
Original keywords: puuaines; puuaineen tiheys; taivutuslujuus; puristuslujuus; kutistuminen; kotipihlaja; kuoren tiheys
English keywords: wood properties; bark; basic density; shrinkage; bending strength; compression strength; rowan; Sorbus aucuparia
Abstract | View details | Full text in PDF | Author Info

The basic density of the wood of the rowan tree (Sorbus aucuparia L.) is almost the same along the stem but that of the bark is increasing along the stem. The moisture content of the wood and of the bark is increasing along the stem. Its strength in the bending and in the compression is high. The volume shrinkage is high.

The PDF includes an abstract in Finnish

  • Maasalo, E-mail: km@mm.unknown (email)
article id 5275, category Article
Pirkko Velling, Gérard Nepveu. (1986). Männyn puuaineen laadun ja tuotoksen vaihtelu suomalaisessa provenienssikoesarjassa. Silva Fennica vol. 20 no. 3 article id 5275. https://doi.org/10.14214/sf.a15454
English title: Variation of wood quality and yield in a Finnish series of provenance trials on Scots pine.
Original keywords: mänty; kasvupaikka; alkuperä; puuaineen tiheys; maantieteellinen vaihtelu; kuitusaanto
English keywords: Pinus sylvestris; Scots pine; wood density; geographical variation; increment cores; fibre yield
Abstract | View details | Full text in PDF | Author Info

The purpose of the study was to determine the effects of the origin of seeds and the location of cultivation of Scots pine (Pinus sylvestris L.) on certain properties particularly important to the pulp industry. The research material consisted of six parallel trials of the same 12 provenances. Increment cores were taken of a total of 1,267 sample trees, 19 years old. The location of the trial site generally affected the properties to a larger extent than the origin of the seed. The effect of the variation of wood density and fibre yield on the cultivation values of the provenances was only a few percentages on average, however, at most the effect was nearly 10%. Eastern Finnish provenances adapted well to western Finnish conditions.

The PDF includes an abstract in Finnish and French.

  • Velling, E-mail: pv@mm.unknown (email)
  • Nepveu, E-mail: gn@mm.unknown
article id 5261, category Article
Matti Kärkkäinen. (1986). Koivuvaneritukkien ja -runkojen arvosuhteet. Silva Fennica vol. 20 no. 1 article id 5261. https://doi.org/10.14214/sf.a15440
English title: Value relations of birch veneer logs and stems in Finland.
Original keywords: koivu; järeys; vaneri; mallinnus; koivuvaneritukki; viilun sorvaus; puustamaksukyky
English keywords: Betula pendula; Betula pubescens; simulation; plywood; log size; birch veneer; veneer logs; value of raw material
Abstract | View details | Full text in PDF | Author Info

A model was developed in order to describe the peeling of veneer for determining value relationship for birch veneer logs and stems. The model was based on selling prices of veneer and other products as well as processing costs. The model was utilized for determining the effect of various input variables on the log value.

According to the results, the effect of tree size was important for the value of raw material. Even knottiness had an effect although only in the higher manufacturing costs of knotty veneer were taken into account. Pruning was a method to increase substantially the proportion of knotless veneer.

The PDF includes an abstract in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5259, category Article
Kari Löyttyniemi, Olli Uusvaara. (1986). Further tests for termite resistance of Finnish pine heartwood. Silva Fennica vol. 20 no. 1 article id 5259. https://doi.org/10.14214/sf.a15438
Keywords: Pinus sylvestris; heartwood; resistance; Macrotermitinae; insect attact
Abstract | View details | Full text in PDF | Author Info

The natural resistance of Finnish-grown Pinus sylvestris L. heartwood to Macrotermitinae termites was tested in Zambia in graveyard conditions. The heartwood exhibited some natural resistance but durability was, however, far from practical immunity. There was significant tree-to-tree variation in the resistance of heartwood of P. Sylvestris.

The PDF includes a summary in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
  • Uusvaara, E-mail: ou@mm.unknown
article id 5238, category Article
Matti Kärkkäinen. (1985). Suomalaisen kuusen puuaineen vertailua Keski-Euroopassa kasvaneiden kuusi- ja jalokuusilajien puuaineeseen. Silva Fennica vol. 19 no. 2 article id 5238. https://doi.org/10.14214/sf.a15417
English title: Norway spruce wood grown in Finland compared with spruce and fir wood grown in Central Europe.
Original keywords: puutavara; Suomi; kuuset; puuaines; Keski-Eurooppa; lujuus; puuaineen tiheys; vuosiluston paksuus; kutistuminen
English keywords: Norway spruce; wood properties; density; Picea; sawn goods; Abies; shrinkage; width of growth rings
Abstract | View details | Full text in PDF | Author Info

The aim of this literature review was to compare Finnish Norway spruce (Picea abies (L.) H. Karst.) sawn goods to Central European spruce sawn goods which contain fir in some amount. However, it was found that no statistically valid comparisons have been made. Therefore, conclusions have been based mainly on the relationship between various properties and growth rate. According to this analysis, most properties of Finnish spruce are better, although small in practice.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5231, category Article
Matti Kärkkäinen, Michel Marcus. (1985). Shrinkage properties of Norway spruce wood. Silva Fennica vol. 19 no. 1 article id 5231. https://doi.org/10.14214/sf.a15410
Keywords: Norway spruce; Picea abies; wood properties; basic density; volumetric shrinkage; longitudinal shrinkage; dry density
Abstract | View details | Full text in PDF | Author Info

Norway spruce (Picea abies (L.) H. Karst.) boards sawn from outer layers of logs were sampled from a sawmill in Northern Finland and another in Southern Finland. Test pieces 20 mm x 20 mm x 20 mm were selected according to maximum variation in growth ring width. Volumetric and longitudinal shrinkage from a soaked to a dry condition were measured. It was found that wood density correlated positively with the volumetric shrinkage but negatively with the longitudinal shrinkage. Dry density was a better predictor than basic density. With constant density and an increase in growth ring width, there was increased shrinkage, especially in samples from Northern Finland. Besides this, when density was kept constant, the shrinkage was higher in the spruce wood from Southern Finland than from Northern Finland.

The PDF includes a summary in Finnish.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
  • Marcus, E-mail: mm@mm.unknown
article id 5228, category Article
Pekka Saranpää. (1985). Kontortamännyn runkopuun trakeidien pituuden, halkaisijan ja soluseinän paksuuden vaihtelu. Silva Fennica vol. 19 no. 1 article id 5228. https://doi.org/10.14214/sf.a15407
English title: Length, diameter and cell wall thickness of tracheids in mature lodgepole pine bole wood.
Original keywords: puuaines; kontortamänty; trakeidit; puuaineen rakenne
English keywords: wood properties; lodgepole pine; Pinus contorta; wood anatomy; tracheids
Abstract | View details | Full text in PDF | Author Info

Variation in tracheid morphology were examined for the bole wood of lodgepole pine (Pinus contorta Douglas ex Loudon) grown in Southern and Central Finland. Tracheid lengths were examined in a fast-grown and in slow-grown trees from three stands. Tracheid length increased with increasing height to 4–8 metres and decreased after that, and increased also with increasing age from the pith. The variation between stems was high. The shortest tracheids were about 1.11 mm near the piths and the longest about 4.10 mm near the bark.

Tracheid diameter and cell wall thickness were measured for the total number of 16 stems from Southern and Central Finland. Tracheid diameter increased with increasing distance from pith and the largest tracheids were at a height of 4–8 metres. Cell wall thickness varied independently of height in the stem. Summerwood cell wall thickness was twice that of springwood. There was a difference of 0.6 μm in springwood and 1.0 μm in summerwood double cell wall thickness between the two stands. Cell wall percentage was 29±4.7 in springwood and 69±7.3 in summerwood.

The PDF includes a summary in English.

  • Saranpää, E-mail: ps@mm.unknown (email)
article id 5187, category Article
Fuhe Luo. (1983). Determination of stem value. Silva Fennica vol. 17 no. 3 article id 5187. https://doi.org/10.14214/sf.a15170
Keywords: Pinus sylvestris; Scots pine; modelling; pulpwood; saw log; stem value; taper curve model; bark model; cubic spline interpolation
Abstract | View details | Full text in PDF | Author Info

A dynamic programming approach toward stem value estimation for standing Scots pine (Pinus sylvestris L.) trees was developed. The determination of the saw log value was based on the sawing pattern and on the final products composition. The combination of taper curve models and bark models providing taper curves both over bark and under bark, which constituted the basis of the optimum stem scaling. A computer program was developed to determine the optimum log sequence of the stem aiming at maximizing the value of the final products. To examine the reliability of the computation system, 445 Scots pine sample trees from 29 stands were used as a test material. The stem values of sample trees were calculated in two ways: 1) with 12 measured diameters, and 2) with 12 estimated diameters derived from measured tree characteristics. In both cases the values of the intermediate diameters were calculated via cubic spline interpolation.

The PDF includes a summary in Finnish.

  • Luo, E-mail: fl@mm.unknown (email)
article id 5177, category Article
Kari Löyttyniemi. (1983). Preliminary testing of the resistance of Finnish softwood timbers to Macrotermitinae termites. Silva Fennica vol. 17 no. 1 article id 5177. https://doi.org/10.14214/sf.a15092
Keywords: Pinus sylvestris; insect damages; insect resistance; Macrotermitinae termites; sofwood timber; Juniperus communis; Microtermes; Odontotermes; Zambia
Abstract | View details | Full text in PDF | Author Info

The resistance of Finnish softwood timbers to Macrotermitinae termites was tentatively tested under tropical conditions in Zambia using a field microtest method. Picea abies (L.) H. Karst. and Larix sibirica L. sapwood and heartwood, as well as Pinus sylvestris L. sapwood, and the sapwood of the locally grown Pinus kesiya, exhibited no natural termite resistance. On the other hand, Juniperus communis heartwood appeared to be virtually immune and the heartwood of P. Sylvestris had some resistance. There were also some differences in the resistance of the heartwood of the different P. Sylvestris individuals tested, which was correlated with the width of the annual rings in the wood samples. The termite species involved were Microtermes sp. and Odontotermes sp. The possibilities of using different types of Finnish softwood timber in the regions in the tropics where there is a risk of termite damage is discussed.

The PDF includes a summary in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 5166, category Article
Rihko Haarlaa, Matti Kärkkäinen. (1982). Tervalepän kuitujen pituus. Silva Fennica vol. 16 no. 4 article id 5166. https://doi.org/10.14214/sf.a15081
English title: Fibre length in common alder.
Original keywords: kuitupuu; tervaleppä; puun anatomia; kuidut
English keywords: fibre length; Alnus glutinosa; pulpwood; fibres
Abstract | View details | Full text in PDF | Author Info

A material consisting of 21 common alder (Alnus glutinosa (L.) Gaertn.) trees from 11 stands was collected. From each stem discs were sawn by 2 m interval. Samples were taken of the discs from various distances from pith. They were macerated and the average fibre length was based on 50 observations.

The fibre length increased significantly from the pith to the disc surface. The increase was approximately similar at various heights of the tree. The tree characteristics had only minor effect. However, near the pith the increase in fibre length was higher in trees with wide growth rings than in other trees. Near the disc surface the growth rate had no effect. In typical pulpwood bolts the average length was 800–950 μm which corresponds well to the data given in the literature.

The PDF includes a summary in English.

  • Haarlaa, E-mail: rh@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5165, category Article
Päiviö Riihinen. (1982). Roundwood market: A source of stagnation of the forest industries. Silva Fennica vol. 16 no. 4 article id 5165. https://doi.org/10.14214/sf.a15080
Keywords: forest owners; forest taxation; private forests; timber sales; wood supply; behaviour
Abstract | View details | Full text in PDF | Author Info

Certain trends in the sales behaviour of private non-industrial forest owners suggest that the forest industries have to rely on a raw material supply much less than the allowable cut. This paper deals with several factors responsible for the change in sales behaviour during the last 20–25 years. These changes are caused by social change, a multi-face process which is led by industrialization. It is manifested in the increasing division of labour, more pronounced strive for efficiency, change in social values for the benefit of the adoption of innovations and thus of further changes.

It has become more common than previously to borrow money instead of selling timber. An incentive for doing so is provided by the increased progression of income tax scales which makes it more profitable than earlier to substitute a loan for timber sales with a view to reduce the amount of taxes. In 1977, the real value of the farmers’ debts was 1.7 times as large as in 1970. Inflation provides a further incentive to borrow money rather than to sell timber, because it tends to reduce debts, whereas a growing stock keeps increasing without affecting the property taxation, maintaining its real unit value.

Certain forestry policy measures conductive to increasing the forest owner’s willingness to sell timber are suggested. Among the most promising seems to be an adjustment of the present area-based yield taxation so as to take into account the age class distribution of the growing stock.

The PDF includes a summary in Finnish.

  • Riihinen, E-mail: pr@mm.unknown (email)
article id 5162, category Article
Jarmo Eronen. (1982). Soviet pulp and paper industry: Factors affecting its areal expansion. Silva Fennica vol. 16 no. 3 article id 5162. https://doi.org/10.14214/sf.a15077
Keywords: paper industry; pulp industry; Soviet Union; USSR; investment strategy; wood raw material; timber reserves; relative costs
Abstract | View details | Full text in PDF | Author Info

Planners of the Soviet pulp and paper industry are constantly faced with the problem: which investment policy guarantees the best location structure? Should one invest in existing localities or expand to new areas, especially in heavily forested parts of Siberia? A location theory for the pulp and paper industry, based on three factors (markets, wood raw materials, relative costs) has been suggested by the Soviet authors Antonov and Trusova. In the present study the theory is – for the first time – given empirical contents and the feasible areas for future growth of the industry are tentatively determined. One of the main findings of the study is the detecting of considerable unutilized wood reserves in the European USSR. This supports those Soviet views advocating a European-oriented location in investment strategy for the industry, as market and cost factors are unfavourable to Siberian location.

The PDF includes a summary in Finnish.

  • Eronen, E-mail: je@mm.unknown (email)
article id 5155, category Article
K. M. Bhat, Matti Kärkkäinen. (1982). Wood anatomy and physical properties of the wood and bark in Betula nana growing in Finland. Silva Fennica vol. 16 no. 1 article id 5155. https://doi.org/10.14214/sf.a15070
Keywords: Betula nana; bark; basic density; wood anatomy; growth rings; vessels; fibres
Abstract | View details | Full text in PDF | Author Info

Eighty Betula nana samples were collected from three swamp sites. In the butt portion of the dwarf shrub the average number of growth rings was 12 and the average diameter of the sprouts 6 mm. The basic density of wood was 457 kg/m3 and that of bark 544 kg/m3. The proportion of bark was 32–38% of weight or volume. The vessel elements and fibres were short and their diameter small. The proportion of vessels was 15%, that of fibres 70% and that of rays 15%.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5118, category Article
Matti Nuorteva, Jyrki Patomäki, Lennart Saari. (1981). Large poplar longhorn, Saperda carcharias (L.), as food for white-backed woodpecker, Dendrocopos leucotos (Bechst.). Silva Fennica vol. 15 no. 2 article id 5118. https://doi.org/10.14214/sf.a15059
Keywords: Populus tremula; nature conservation; aspen; Saperda carcharias; Dendrocopos leucotos; white-backed woodpecker; larvae; pupal chambers
Abstract | View details | Full text in PDF | Author Info

In a locality in Southern Finland where the white-backed woodpecker, Dendrocopos leucotos (Bechst.), was previously breeding was found many conical borings excavated during the winter in young aspens (Populus tremula L.) on average 8.1 cm in diameter. Full-grown larvae of Saperda carcharias (L.) (Coleoptera, Cerambycidae) hibernated in pupal chambers constructed about 0.5 m above ground level. Below this chamber the larva has usually prepared an exit hole. After the larva has blocked itself in the pupating chamber it is easy to prey for the woodpecker during the whole winter.

There were usually 1–5 conical borings in the same trunk. The number of these borings did not correspond with the amounts of larvae eaten, since the woodpecker often made these borings in places from which it could not obtain a prey. The woodpeckers stopped excavating in those cases when the larvae in the galleries were dead. The exit holes and the conical borings occluded within a few years. The galleries within the tree will not heal and several years later a new larva may utilize them. In the wintering habitats of the white-backed woodpecker the availability of food could be improved by increasing the amount of S. sarcharias larvae. This is easily done by encouraging young aspens.

The PDF includes a summary in Finnish.

  • Nuorteva, E-mail: mn@mm.unknown (email)
  • Patomäki, E-mail: jp@mm.unknown
  • Saari, E-mail: ls@mm.unknown
article id 5115, category Article
K. M. Bhat, Matti Kärkkäinen. (1981). Variation in structure and selected properties of Finnish birch wood. II. Silva Fennica vol. 15 no. 2 article id 5115. https://doi.org/10.14214/sf.a15056
Keywords: Betula pendula; Betula pubescens; basic density; wood anatomy; roots
Abstract | View details | Full text in PDF | Author Info

The anatomical variation of a lateral root was compared with that of the stem of the same tree at breast height by concentrating on the intrelationships of certain anatomical features in Betula pendula and B. pubescens. The results showed that root wood has several essential features of stem wood, such as gelatinous fibres, growth eccentricity, scalariform perforation plates in the vessels and pith flecks. However, some of the anatomical differences are significant. The differences between the species were more pronounced in the root than in the stem anatomy.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5113, category Article
K. M. Bhat, Matti Kärkkäinen. (1981). Wood anatomy and physical properties of wood and bark in Betula tortuosa Ledeb. Silva Fennica vol. 15 no. 2 article id 5113. https://doi.org/10.14214/sf.a15054
Keywords: bark; basic density; wood anatomy; Betula pubescens ssp. czerepanovii; perforation plates
Abstract | View details | Full text in PDF | Author Info

Ten trees of mountain birch (Betula tortuosa Ledeb, now Betula pubescens subsp. czerepanovii) with an average age of 39 years were sampled in northern Lapland in Finland. The average green density of wood was 589 kg/m3 and that of bark 941 kg/m3. The basic densities were 520 kg/m3 and 559 kg/m3, respectively. The basic density increased only little from the pith to the surface. In contrast, the number of bars in the perforation plates of the vessels increased considerably in the same direction. The average number of bars was 17.3.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5097, category Article
K. M. Bhat, Ari Ferm, Matti Kärkkäinen. (1981). On the properties of one-year shoots of Betula pubescens Ehrh. and Salix spp. Silva Fennica vol. 15 no. 1 article id 5097. https://doi.org/10.14214/sf.a15038
Keywords: Betula pubescens; wood properties; bark; basic density; willows; vessels; fibers; Salix sp.; shoots
Abstract | View details | Full text in PDF | Author Info

Downy birch (Betula pubescens Ehrh.) trees growing on a drained peatland were cut during dormancy. The properties of the one-year old shoots produced by the stumps were measured in the autumn after one growing season. The one-year old willow shoots (a mixture of Salix phylicifolia L., S. pentandra L. and S. caprea L.) were collected from an abandoned field.

The basic density of unbarked shoots was 443 kg/m3 for birch and 346 kg/m3 for willow. The basic density of the bark was much higher than that of the wood. The effect of shoot length on the properties was small with the exception of cellular proportions. The fibre percentage increased and vessel percentage decreased with increasing shoot length.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
  • Ferm, E-mail: af@mm.unknown
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5096, category Article
K. M. Bhat, Matti Kärkkäinen. (1981). Variation in structure and selected properties of Finnish birch wood. IV. Silva Fennica vol. 15 no. 1 article id 5096. https://doi.org/10.14214/sf.a15037
Keywords: Betula pendula; Betula pubescens; branches; wood anatomy; roots; stem; vessels; fibres
Abstract | View details | Full text in PDF | Author Info

Length variation of fibres and vessels was studied in the branches, stems and roots of Betula pendula Roth and B. pubescense Ehrh. The cells were significantly shorter in the branches and roots than in the stems. There was no significant difference in the cell length between the upper and lower radii of the branches and roots. The length increased from the pith to the surface and decreased in the branches and stems from the base onwards. In the roots the length increased in that direction. The differences between the tree species were small although the cells of B. pubescens were a little longer.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5095, category Article
K. M. Bhat, Matti Kärkkäinen. (1981).  . Silva Fennica vol. 15 no. 1 article id 5095. https://doi.org/10.14214/sf.a15036
English title: Variation in structure and selected properties of Finnish birch wood. III.
Keywords: Betula pendula; silver birch; branches; wood anatomy; parenchyma; stem; vessels; fibers
Abstract | View details | Full text in PDF | Author Info

Variation of cellular proportion within the same growth rings counted from the pith of the stems and branches in four trees of Betula pendula Roth was studied. The fibre percentage decreased from breast height to the crown and then increased in the branches. The reverse trend was found in the percentage of vessels and parenchyma, although the latter varied relatively little. No statistically significant differences were found in the percentages of fibres, vessels and rays within the same growth rings counted from the pith between the stems and branches. In both the stem and the branches, the proportion of fibres increased and that of vessels and rays decreased from the pith to the surface. Even crown formed wood differed from that of stem formed. 

The PDF includes a summary in Finnish. 

  • Bhat, E-mail: kb@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5091, category Article
K. M. Bhat. (1980). Variation in structure and selected properties of Finnish birch wood. I. Silva Fennica vol. 14 no. 4 article id 5091. https://doi.org/10.14214/sf.a15032
Keywords: birch; Betula pendula; Betula pubescens; density; wood characteristics; wood anatomy; shrinkage
Abstract | View details | Full text in PDF | Author Info

Variation of wood characteristics was studied in two mature trees of Betula pendula Roth and two of B. pubescens Ehrh. by stressing the interrelationships of some of the structural features, basic density and shrinkage. Correlation analysis revealed that basic density was related to some of the variables studied, viz: number of rings (age) and distance from pith, height from the ground, ring width, fibre length and double wall thickness. Multiple regression equation showed that age from pith and height from the ground explained 80% of variation of basic density in B. pendula. Two structural variables, viz: fibre wall thickness and ring width accounted for only 28% of variation of basic density in B. pubescens. No significant relations could be found between shrinkage and any of the wood parameters measured in B. pendula while some of the relationships were significant in B. pubescens. However, only 55% of variation of volumetric shrinkage was explained by two related factors, viz: basic density and moisture content while only 35% of variation of tangential shrinkage was explained by ring width and fibre width. Increase in fibre length was highly associated with the increase in fibre width, double wall thickness and vessel length in either species.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
article id 5084, category Article
K. M. Bhat, Matti Kärkkäinen. (1980). Distinguishing between Betula pendula Roth. and Betula pubescens Ehrh. on the basis of wood anatomy. Silva Fennica vol. 14 no. 3 article id 5084. https://doi.org/10.14214/sf.a15025
Keywords: Betula pendula; Betula pubescens; wood anatomy; identification; perforation plate
Abstract | View details | Full text in PDF | Author Info

It was concluded on the basis of the anatomical investigations of four mature trees that Betula pendula Roth can be distinguished from B. pubescens Ehrh. using the number of bars per scalariform perforation plate as an identification factor. If the average number of bars is more than 17.6, the sample is probably from B. pubescens, and if less, from B. pendula. The accuracy can be slightly improved by using the vessel frequency as another factor.

The PDF includes a summary in Finnish.

  • Bhat, E-mail: kb@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5082, category Article
K. M. Bhat. (1980). Pith flecks and ray abnormalities in birch wood. Silva Fennica vol. 14 no. 3 article id 5082. https://doi.org/10.14214/sf.a15023
Keywords: Betula pendula; Betula pubescens; wood structure; insect damage; rays; Dendromyza betulae; Phytobia betulae
Abstract | View details | Full text in PDF | Author Info

Samples that had extensive pith flecks, caused by the larvae of Dendromyza betulae (now Phytobia betulae E.Kang), were collected from two trees of Betula pendula Roth and two B. pubescens Erhr. The age of the trees varied from 45 to 56 years. The effect of larvae injury on the rays was studied. The width of affected rays in both species was more than twice that of normal rays. The height and frequency also increased considerably. When describing the anatomy of Betula species the pith flecks should be treated with caution in order to avoid confusion and misinterpretation. 

The PDF includes a summary in Finnish. 

  • Bhat, E-mail: kb@mm.unknown (email)
article id 5080, category Article
Annikki Mäkelä, Pertti Hari, Seppo Kellomäki. (1980). Eco-physiological studies on young Scots pine stands. III. Silva Fennica vol. 14 no. 3 article id 5080. https://doi.org/10.14214/sf.a15021
Keywords: Pinus sylvestris; biomass; Scots pine; canopy layer; wood formation; needle biomass; photosynthate allocation
Abstract | View details | Full text in PDF | Author Info

The proportions of needle and wood in current-year shoots in crown systems of young Scots pine (Pinus sylvestris L.) trees was studied. The proportion of needles out of the total shoot biomass increased according to the increasing number of the whorl counted from the apex. In the lower part of the crown system the needle biomass of newly-formed shoots was 50–60 fold compared to that of wood and bark biomass. In the upper part of the crown system the same ratio was 1–2. The variation in ratio between needle and wood biomass was whorl-specific and independent of tree class. The magnitude of the ratio was not related to the position of the tree in the stand nor to the prevailing light conditions within the state.

The PDF includes a summary in Finnish.

  • Mäkelä, E-mail: am@mm.unknown (email)
  • Hari, E-mail: ph@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
article id 5051, category Article
Aili Tuimala. (1979). Kuusen lahon aiheuttamista puutavaralajisiirtymistä ja kantohintamenetyksistä. Silva Fennica vol. 13 no. 4 article id 5051. https://doi.org/10.14214/sf.a14908
English title: Changes in timber assortments and loss in stumpage prices caused by decay in growing Norway spruce timber.
Original keywords: kuusi; kuitupuu; puukauppa; tukkipuu; laho; puutavaralaji; tulonmenetys; puutavaralajisiirtymä
English keywords: Norway spruce; Picea abies; pulpwood; decay; timber; timber assortments; loss of income
Abstract | View details | Full text in PDF | Author Info

Material for this study was collected from 26 stands marked for clear cutting in Southern Finland. The volume of decayed Norway spruce (Picea abies (L.) H. Karst.) timber and pulpwood was determined by deducting the volumes of these assortments (as recorded on the measurement certificate) from the volume of the standing trees. To obtain the economic loss, the volume of decayed wood was multiplied by the difference in stumpage prices between spruce timber of pulpwood and pine pulpwood. In the 17 stands of Buyer A the loss in timber volume caused by decay was 5.84% and the loss in stumpage price 2.84 Fmk/m3 (means weighted by volume). The corresponding figures in the 9 stands of Buyer B were 10.87% and 5.50 Fmk/m3, respectively.

At the mean stumpage price level for the felling season 1977-78 the losses in the stands m.f.c. mentioned above were 2.87% per unit price in the stands of Buyer A and 5.75% in the stands of Buyer B.

The PDF includes a summary in English.

  • Tuimala, E-mail: at@mm.unknown (email)
article id 5034, category Article
Matti Kärkkäinen. (1979). Pinotilavuusmääräinen kuorintahäviö koneellisesti ladotuissa pinoissa. Silva Fennica vol. 13 no. 2 article id 5034. https://doi.org/10.14214/sf.a14891
English title: Barking loss of mechanically loaded piles.
Original keywords: kuitupuu; mänty; puutavaranmittaus; koivu; kuorinta; pinotilavuus
English keywords: birch; Scots pine; pulpwood; debarking; piled volume; stacked volume; barking loss
Abstract | View details | Full text in PDF | Author Info

In this study the loose volume of 58 piles of pulpwood were measured before and after barking by rotary ring barker. The volume was 2,121 m3. A recommendation is made, based on the results of the study, concerning the barking loss from piled wood: for green Scots pine (Pinus sylvestris L.) pulpwood, 8.8% of the stacked volume; for seasoned pine pulpwood, 6.1% of the stacked volume; and 8.0% for birch (Betula sp.) pulpwood, green and seasoned. The amount of bark left on bolts was small for pine bolts, namely 0.33%, but quite large for birch bolts, 2.84% of the green weight.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5017, category Article
T. Raunemaa, A. Hautojärvi, P. Jartti, J. Laurén, V. Lindfors, J. Räisänen. (1979). Trace element analysis of sound and decayed Norway spruce (Picea abies) by XRF and NAA methods. Silva Fennica vol. 13 no. 1 article id 5017. https://doi.org/10.14214/sf.a14871
Keywords: Norway spruce; Picea abies; wood; decay; measuring methods; trace elements; of fast neutron activation analysis; by X-ray fluorescence analysis
Abstract | View details | Full text in PDF | Author Info

Ashed tree samples from sound and decayed Norway spruce (Picea abies (L.) H. Karst.) were studied by means of fast neutron activation analysis, and for comparison, also by X-ray fluorescence analysis. In fast neutron activation analysis, the following elements were detected: (Na), Mg, Al, Si, K, Ca, Mn, Rb, Sr and Ba, and according to the results of the X-ray fluorescence method the elements present in the wood samples were: K, Ca, Mn, Rb, Sr and Ba. A general diminishing was revealed by both methods in most elemental concentrations studied, with exception of K and Rb, when going from a sound tree to a decayed one. The use of the ratio of the amounts of potassium to calcium as an indication of the degree of decay is therefore proposed.

The PDF includes a summary in Finnish.

  • Raunemaa, E-mail: tr@mm.unknown (email)
  • Hautojärvi, E-mail: ah@mm.unknown
  • Jartti, E-mail: pj@mm.unknown
  • Laurén, E-mail: jl@mm.unknown
  • Lindfors, E-mail: vl@mm.unknown
  • Räisänen, E-mail: jr@mm.unknown
article id 5014, category Article
Matti Nuorteva. (1979). Punapuiden suojeluongelmia Kaliforniassa. Silva Fennica vol. 13 no. 1 article id 5014. https://doi.org/10.14214/sf.a14868
English title: Preservation problems of redwoods in California.
Original keywords: Yhdysvallat; mammuttipetäjä; punanpuu; Kalifornia; suojelu
English keywords: protection; United States; Sequoia sempervirens; Sequoiadendron giganteum; redwood; California
Abstract | View details | Full text in PDF | Author Info

The paper deals with the problems of the preservation of the redwood groves (Sequioia sempervirens (D. Don) Endl. and Sequoiadendron giganteum (Lindl.) J. Buchholz) in California. The activity to protect these groves from flood and fire may finally lead to dying of these long-lived trees. A program to use prescribed burning as a tool for the management of natural ecosystem has been started.

The PDF includes a summary in English.

  • Nuorteva, E-mail: mn@mm.unknown (email)
article id 5005, category Article
Matti Kärkkäinen. (1978). Kuorinnan vaikutus pinon tiiviyteen. Silva Fennica vol. 12 no. 3 article id 5005. https://doi.org/10.14214/sf.a14859
English title: The effect of barking on the pile density.
Original keywords: koneellistuminen; karsinta; kiintotilavuus; kuitupuun mittaus; pinomittaus; kuorinta; moottorisahakarsinta
English keywords: mechanization; pulpwood; limbing; pile density; measuring of piled wood; solid volume; debarking
Abstract | View details | Full text in PDF | Author Info

According to the available literature, the times when pulpwood limbing was made by axe and barking by hand tools, barking either had no effect on the pile density (if limbing quality was good) or increased pile density (if limbing was bad). When rotary barking machines are used, the branch stumps remain intact during barking. Therefore, if there are branch stumps in the pulpwood, barking decreases the pile density. Nowadays, when power saw limbing is a common practice in Finland, barking presumably greatly decreases the pile density, due to the fact that in power saw limbing branch stumps are numerous and high. Therefore, the method to estimate the solid volume of a pile of unbarked pulpwood are not applicable to barked pulpwood without modification.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4988, category Article
Irja Lehtonen. (1978). Ravinteiden kierto eräässä männikössä. Silva Fennica vol. 12 no. 1 article id 4988. https://doi.org/10.14214/sf.a14842
English title: Nutrient cycle in a Scots pine stand: IV The amount of phytomass and nutrients.
Original keywords: mänty; aluskasvillisuus; ravinteet; biomassa; ravinnekierto; kuiva-aine; runkopuu
English keywords: Pinus sylvestris; biomass; Scots pine; nutrients; ground vegetation; dry matter; stemwood
Abstract | View details | Full text in PDF | Author Info

The distribution of the dry matter and nutrients in Scots pine (Pinus sylvestris L.) tree stock growing on a Vaccinium type site, ground vegetation, and humus were determined in the study. The greatest part of the dry matter in the tree was found in the stemwood. The living branches, roots, bark, needles and dead branches decreasing order of magnitude made up the rest of the biomass. The trees contained over 90%, the field layer vegetation 3% and the bottom layer vegetation 2% of the dry matter in the tree stand. The tree stock contained 86–95% of the total amount nutrients in the stand. The field layer vegetation contained less nutrients than the bottom layer vegetation. Nitrogen, however, was an exception, the amount being approximately the same in both vegetation layers. 

The PDF includes a summary in English.

  • Lehtonen, E-mail: il@mm.unknown (email)
article id 4986, category Article
John E. Høsteland. (1978). Raakapuun hintasopimukset Norjassa. Silva Fennica vol. 12 no. 1 article id 4986. https://doi.org/10.14214/sf.a14840
English title: Collective timber price agreements in Norway.
Original keywords: metsätalous; raakapuu; puumarkkinat; puun hinta; hintasopimukset; Norja
English keywords: roundwood market; Norway; timber market; timber prices; timber price agreement
Abstract | View details | Full text in PDF | Author Info

In this paper the system of collective timber price agreement in Norway is described. The history of »collective behaviour» in the roundwood market can be tracked far back in history, with different degrees of importance, and it has totally dominated the price-formation of roundwood from the 1950’s until the present. In trying to answer the question »What has been the effect of the collective price agreements» a few theoretical market models are used and the empirical data are also employed. Both the theoretical discussion and the empirical data seem to indicate that the forest owners are better off with collective price agreements than with a situation where there are no organized price-negotiations.

The PDF includes a summary in English.

  • Høsteland, E-mail: jh@mm.unknown (email)
article id 4974, category Article
Markku Mäkelä. (1977). Teknisesti korjattavissa oleva hakkuutähde sekä kanto- ja juuripuu Kaakkois-Suomessa. Silva Fennica vol. 11 no. 3 article id 4974. https://doi.org/10.14214/sf.a14825
English title: The amounts of logging residues and stump and root wood technically harvestable in southeast Finland.
Original keywords: puunkorjuu; kannot; hakkuutähde; juuret; Kaakkois-Suomi
English keywords: stumps; timber harvesting; logging residue; roots; stemwood; southeast Finland
Abstract | View details | Full text in PDF | Author Info

The amounts of harvestable logging residues and stump and root wood were examined in the area where 100,000 solid m3 of stemwood was cut in 1975. The cutting amounts of stemwood from work sites suitable for harvesting of logging residues was 35,000 m3, and suitable for harvesting of stump and root wood 38,000 m3. The increase in the yield of wood (without bark) from logging residues compared with the unbarked stemwood was 2.4%. The same percentage of wood from stump and root wood was 5.0–5.8% depending on the harvesting loss.

The PDF includes a summary in Finnish.

  • Mäkelä, E-mail: mm@mm.unknown (email)
article id 4970, category Article
Markku Mäkelä. (1977). Metsähakkeen tiheyden laskeminen. Silva Fennica vol. 11 no. 2 article id 4970. https://doi.org/10.14214/sf.a14821
English title: Calculating the basic density of whole tree- and logging residue chips.
Original keywords: kuusi; tiheys; mänty; koivu; hake; metsähake; kokopuuhake; leppä
English keywords: Norway spruce; birch; Scots pine; basic density; alder; wood chips; logging residue; whole tree chips
Abstract | View details | Full text in PDF | Author Info

A method is presented in this study for calculating the basic density of whole tree- and logging residue chips and the results of trial measurements on some commonly used chip sorts. The basic density of Scots pine whole tree chips was found to be 1–18 kg/m3 smaller than that of pine pulpwood of the same age. The basic density of Norway spruce whole tree chips was 4–22 kg/m3 greater than that of similar aged pulpwood. The basic density of birch whole tree chips was 4–16 kg/m3 and grey alder whole tree chips 7–24 kg/m3 greater than pulpwood of the same age. The basic density of conifer logging residue chips was considerably greater than that of pine and spruce whole tree ships.

The PDF includes a summary in English.

  • Mäkelä, E-mail: mm@mm.unknown (email)
article id 4966, category Article
Markku Mäkelä. (1977). Seulontatuloksia Algol-monikäyttöhakkurin hakkeesta. Silva Fennica vol. 11 no. 2 article id 4966. https://doi.org/10.14214/sf.a14817
English title: Screening results on the chips made by Algol-multipurpose chipper.
Original keywords: hake; hakkurit; hakkeen laatu
English keywords: wood chips; chip quality; Algol chipper
Abstract | View details | Full text in PDF | Author Info

The first part of this paper consists of a study based on the available literature concerning the analysis of chip quality in the sulphate pulp process and the factors having an effect on chip quality. Using the empirical material, the suitability of the Williams chip classifier in evaluating the quality of chips made by the Algol chipper is first studied. The distribution of length and thickness of pulpwood-, long logs-, whole tree-, and logging residue chips in different conditions determined by screening is then presented.

The PDF includes a summary in English.

  • Mäkelä, E-mail: mm@mm.unknown (email)
article id 4965, category Article
Matti Kärkkäinen, Marjut Raivonen. (1977). Reaktiopuun mekaaninen lujuus. Silva Fennica vol. 11 no. 2 article id 4965. https://doi.org/10.14214/sf.a14816
English title: Mechanical strength of reaction wood.
Original keywords: lyly; reaktiopuu; vetopuu; lujuus
English keywords: compression wood; mechanical strength; reaction wood; tension wood; softwood species; hardwood species
Abstract | View details | Full text in PDF | Author Info

According to the literature, the mechanical strength of the green reaction wood of softwood species (compression wood) is greater than that of normal wood. Drying increases the mechanical strength but less in reaction wood than in normal wood. In particular, the tensile strength along the grain and the impact strength are lower than in normal wood. The compression strength and possibly bending strength are greater, however.

The properties of the reaction wood of hardwood species (tension wood) differ from those of softwoods. When green, all mechanical properties are weaker than those of normal wood. When dried, the tensile strength and impact strength are better and compression strength lower. There is no great difference in the bending strength.

When the higher density of reaction wood is not taken into account and there are no impact forces, the mechanical strength of reaction wood in sawn goods etc. does not differ so much from that of normal wood. The harmful effect of knots, for example, can in practice be much greater.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
  • Raivonen, E-mail: mr@mm.unknown
article id 4958, category Article
Matti Kärkkäinen. (1977). Araukaarian ja männyn puuaineen ominaisuuksien vertailua. Silva Fennica vol. 11 no. 1 article id 4958. https://doi.org/10.14214/sf.a14809
English title: Comparison of wood properties of Parana pine and Scots pine.
Original keywords: tiheys; mänty; puuaines; pihkatiehyet; araukaaria
English keywords: Pinus sylvestris; Scots pine; wood; density; rays; Araucaria angustifolia; Panama pine
Abstract | View details | Full text in PDF | Author Info

According to the available literature, the appearance of Parana pine (Araucaria angustifolia (Bertol.) Kuntze) wood resembles that of Scots pine (Pinus sylvestris L.). The anatomy is quite different, however. There are no resin canals and fusiform rays with resin canals in Parana pine. They are abundant in Scots pine, however. The basic density of Parana pine is higher. In both species the density increases from the pith outwards, the maximum being reached at the age of 100 years. Compression wood is more common in Parana pine than in Scots pine, and this makes the longitudinal shrinkage of Parana pine greater than that of Scots pine. Otherwise the shrinkage properties do not differ. The mechanical strength is of the same magnitude with the exception of hardness, where Parana pine is superior.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4955, category Article
Suomen Metsäteollisuuden Keskusliitto. (1976). Puutavaraselvitys 1976. Silva Fennica vol. 10 no. 4 article id 4955. https://doi.org/10.14214/sf.a14801
English title: Timber report 1976. – Finland’s roundwood, industrial residue and forest residue balances by 1980 as well as the wood raw material situation of Finnish forest industries by the year 2000.
Original keywords: metsäteollisuus; raakapuu; puuvarat; raaka-aine; metsätase; teollisuusjätepuu; metsätähde
English keywords: Finland; roundwood supply; forest industry; logging residue; timber balance; Central Association of Finnish Forest Industries; industrial residue
Abstract | View details | Full text in PDF | Author Info

This study was carried out on behalf of the Central Association of Finnish Forest Industries (now Finnish Forest Industries Federation) in order to obtain information about the wood raw material situation, to serve, in turn, as a basis for the forest industries’ long-term planning. The study deals with the potential supply of roundwood, industrial residue and forest residue by the year 200 by five wood-supply areas. Examination of the situation during the period of 1972–80 is based on available balances and that concerning the period 1985–2000 in the estimated quantities available for industrial use.

The PDF includes a summary in English.

  • Suomen Metsäteollisuuden Keskusliitto, E-mail:
article id 4947, category Article
Matti Kärkkäinen. (1976). Kokopuuhakkeen tiheyden mittaaminen. Silva Fennica vol. 10 no. 3 article id 4947. https://doi.org/10.14214/sf.a14793
English title: Measurement of basic density of total tree chips.
Original keywords: tiheys; mittausmenetelmät; hake
English keywords: basic density; wood chips; measuring methods
Abstract | View details | Full text in PDF | Author Info

The paper describes a method for the measurement of basic density of total tree chips. In the method the chips are placed in a container, which is immersed in a cylinder full of water, and the container is weighted at two levels. In the upper part of the cylinder the pressure against the air bubbles is smaller than in the lower level. In this method, the effect of air bubbles in the result can be eliminated. Besides this, due to homogenization of the material to be measured only small number of samples are needed for the estimation of the average basic density.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4927, category Article
Matti Kärkkäinen. (1975). Kantojen käytön kehittyminen Suomessa. Silva Fennica vol. 9 no. 4 article id 4927. https://doi.org/10.14214/sf.a14769
English title: Development of stump utilization in Finland.
Original keywords: metsätalous; historia; polttopuu; tervanpoltto; polttoaineet; selluteollisuus; kannot; hyötykäyttö
English keywords: stumps; forestry; fuelwood; history; pulp industry; tar; utilization
Abstract | View details | Full text in PDF | Author Info

The utilization of stump and root wood is analysed in this paper on the basis of literature from middle of 19th century to the present date. According to the information available, the utilization of pine stumps in tar production was small compared to that of peeled Scots pine stemwood in the 19th century. During the 1st and 2nd World War the utilization of stumps for tar production reached its highest levels. Other industrial utilization of stumps has been small up to the present time but now stumps are beginning to be used in the pulp industry.

The greatest amounts of stumps have been utilized by the rural population. Stumps were used as fuel. In the thirties, the yearly amount used was over 200,000 m3 (solid measure), and even in the sixties over 100,00 m3. No industrial utilization method has yet reached these levels.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4915, category Article
Yrjö Roitto. (1975). Raakapuukuljetusten optimointi. Silva Fennica vol. 9 no. 1 article id 4915. https://doi.org/10.14214/sf.a14759
English title: Optimization of roundwood transport.
Original keywords: kaukokuljetus; metsäteollisuus; puunkuljetus; optimointi; kuljetuskustannukset
English keywords: roundwood; timber transport; forest industries; transportation costs; opimization
Abstract | View details | Full text in PDF | Author Info

The paper deals with the optimization of roundwood transport in cases where many destinations for it exist and where several means of transport are available. It is also understood that the capacities of the factories to which wood is transported can be used at varying degree. A model was developed for a case such as Finland which sells most of its products abroad.

In the above case, the optimization of roundwood transport does not necessarily mean minimization of transport costs. What is aimed at is to obtain, by using different combinations (mill destinations and the media of transport) the maximum difference between the allowable cut (calculated) and real (actual) transport costs.

The PDF includes a summary in English.

  • Roitto, E-mail: yr@mm.unknown (email)
article id 4907, category Article
Heikki Wuorenrinne. (1974). Suomen kekomuurahaisten (Formica rufa coll.) ekologiasta ja levinneisyydestä. Silva Fennica vol. 8 no. 3 article id 4907. https://doi.org/10.14214/sf.a14751
English title: About the distribution and ecology of Formica rufa -group in Finland.
Original keywords: metsätyypit; levinneisyys; biologinen torjunta; kekomuurahaiset; muurahaiset; ekologia
English keywords: distribution; forest types; Formica rufa; ants; wood ants; Formica polyctena; Formica aquilonia; Formica lugubris; Formica nigricans
Abstract | View details | Full text in PDF | Author Info

The paper describes the systematics, distribution, abundance and nest sites of Formica rufa -group in different Finnish forest types. In addition, it has been estimated the availability of Finnish ants in the biological competition.

F. polyctena, F. aquilonia and F. lugubris are distributed over whole Finland. F. rufa and F. nigricans to Southern Finland only. The relative abundace of ant nests diminish to Northern Finland. F. rufa -group prefer most forest on moist land (Myrtillus and Oxalis-Myrtillus types), mixed forests of Norway spruce (Picea abies (L.) H. Karsts), Scots pine (Pinus sylvestris L.) and birch (Betula sp.), and the silvicultural density 0.6–0.7 (good or satisfactory density), but they avoid broadleaved and pure one-tree species forests. For the biological competition the most competitive ant species seem to be F. polyctena and F. aquilonia.

The PDF includes a summary in English.

  • Wuorenrinne, E-mail: hw@mm.unknown (email)
article id 4899, category Article
Matti Kärkkäinen. (1974). Näkökohta tyvi- ja latvaläpimitan keskiarvoon perustuvasta mäntypölkkyjen kuutioinnista. Silva Fennica vol. 8 no. 2 article id 4899. https://doi.org/10.14214/sf.a14743
English title: Note on the volume based on the mean of butt and top diameters of Scots pine bolts.
Original keywords: kuitupuu; mänty; puutavaranmittaus; kapeneminen; tyviläpimitta; latvaläpimitta; kiintotilavuus
English keywords: Pinus sylvestris; Scots pine; pulpwood; timber scaling; tapering; butt diameter; top diameter; volume determination
Abstract | View details | Full text in PDF | Author Info

In this paper the use of butt and top diameters of pulpwood bolts for volume determination is analysed. The study is based on the taper data of Scots pine (Pinus sylvestris L.) stems. According to the results, the use of the mean of butt and top diameters in the volume determination under Finnish condition causes a positive error in small stems. If the stems are so big that the butt portions of the stems can be used as saw logs, the remaining top bolts, used as pulpwood, are estimated to be smaller than they are in reality. Accordingly, there is a negative error.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4896, category Article
Matti Kärkkäinen. (1974). Keskusmuotoluvun perusteita tukkien ja kuitupuun mittauksessa. Silva Fennica vol. 8 no. 1 article id 4896. https://doi.org/10.14214/sf.a14740
English title: Foundations of middle form factor in the measurement of logs and pulpwood.
Original keywords: kuitupuu; tukkipuu; puutavaranmittaus; menetelmät; muotoluku; kiintomitta
English keywords: logs; form factor; pulpwood; methods; timber scaling; determination of volume
Abstract | View details | Full text in PDF | Author Info

In this literature review some error possibilities in the measurement of solid volume of logs and pulpwood are discussed. Although both underestimation and overestimation can occur for various reasons it seems likely that in the stereometric measurement method the real volume is underestimated, at least when Huber’s formula is applied, and the respective middle form factors are too low. Numerous results of empirical investigations are presented in the paper, too.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4884, category Article
Kauko Hahtola, Veli-Pekka Järveläinen, Aarne Reunala. (1973). Metsänomistajien puunmyyntikäyttäytyminen. Silva Fennica vol. 7 no. 3 article id 4884. https://doi.org/10.14214/sf.a14721
English title: The timber-sales behaviour of private forest owners.
Original keywords: yksityismetsät; puukauppa; metsänomistajat; hakkuusuunnite; puun tarjonta
English keywords: Finland; forest owners; allowable cut; private forests; timber sales; wood supply
Abstract | View details | Full text in PDF | Author Info

The task of this study was to gather all available information concerning timber-sales behaviour of private forest owners and to try to find the probable trends in this behaviour. The initiative for the study came from the Central Association of Finnish Forest Industries.

In Finland there are areas of timber savings and those of overcutting. These are mainly explained by regional variation in prosperity of forest owners. There are also several individual factors affecting timber sales behaviour. Without major changes in forest policy the annual variation in quantity cut in Finland is increasing and the degree of cutting seem to remain below the allowable cut.

The PDF includes a summary in English.

  • Hahtola, E-mail: kh@mm.unknown (email)
  • Järveläinen, E-mail: vj@mm.unknown
  • Reunala, E-mail: ar@mm.unknown
article id 4883, category Article
Matti Kärkkäinen. (1973). Näkökohta kuitupuupölkkyjen siirtelymatkasta. Silva Fennica vol. 7 no. 3 article id 4883. https://doi.org/10.14214/sf.a14720
English title: A note on the moving distance of pulpwood bolts.
Original keywords: hakkuut; kuitupuu; metsätyö; puunkorjuu; metsäkuljetus; ajourat; kaato; kasaus
English keywords: forest haulage; pulpwood; timber harvesting; fellings; forest work; off-road haulage; strip road; bunching
Abstract | View details | Full text in PDF | Author Info

The aim of the paper was to analyse, using a computer simulation technique, the moving distance of pulpwood bolts when direct felling of trees is used and the bolts are gathered alongside the strip road. According to the results, the average moving distance of bolts depends in a complicated way on the usable part of the stem and the spacing of strip road. As a rule, the differences between moving distances of two-meter bolts weighted and unweighted by bolt volume of various trees is 0–16% when the strip road spacing is 30 m the reason being the fact that the heaviest butt bolts are often more far away from the strip road than the top bolts.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4879, category Article
Matti Kärkkäinen. (1973). Mäntyrunkojen ydinsäteiden määrä ja koko. Silva Fennica vol. 7 no. 2 article id 4879. https://doi.org/10.14214/sf.a14713
English title: Amount and size of rays in Scots pine stems.
Original keywords: mänty; runko; puuaines; ydinsäteet; pihkatiehyet; pihka
English keywords: Pinus sylvestris; Scots pine; structure of wood; fusiform rays; uniseriate rays; resin canal; pitch
Abstract | View details | Full text in PDF | Author Info

The material consists of four Scots pine (Pinus sylvestris L.) stems from which 757 samples were taken from various heights and distances from the pith. According to the results, the number of rays and their sizes are greater at the stump level than higher up in the stem. The size increases, and the number decreases on moving from the pith outwards. However, there are differences between stems as regards the variation model. The ratio between the number of fusiform rays and that of uniseriate rays seems to be lower than anticipated earlier, about 1:40–1:50. The average proportion of ray volume varied from 5.6% to 7.3%.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4872, category Article
Matti Kärkkäinen. (1972). Kuusen ja männyn sydänpuuosuudesta. Silva Fennica vol. 6 no. 3 article id 4872. https://doi.org/10.14214/sf.a14679
English title: The proportion of heartwood in Norway spruce (Picea abies) and Scots pine (Pinus sylvestris).
Original keywords: kuusi; kuitupuu; mänty; sydänpuu; läpimitta
English keywords: Norway spruce; Picea abies; Scots pine; diameter; heartwood; pulpwood; Pinus sylvestri
Abstract | View details | Full text in PDF | Author Info

The study deals with the variation in the proportion of heartwood  in Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) both within and between stems as examined on the basis of literature. Special attention is paid to an application, in which on the basis of the diameter of pulpwood bolts, efforts are made to predict the proportion of heartwood in the total volume of bolts. It is shown that the method, even when based on homogenous material of 564 Norway spruce and Scots pine bolts, easily leads to wrong conclusions concerning the proportion of heartwood.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4846, category Article
Olavi Linnamies. (1971). Metsäteollisuutemme laajennukset ja puuraaka-aineen riittävyys. Silva Fennica vol. 5 no. 3 article id 4846. https://doi.org/10.14214/sf.a14648
English title: Expansion capacity of Finnish forest industries and the sufficiency of wood raw material.
Original keywords: puunkäyttö; metsäteollisuus; Suomi; metsätase; puuntarjonta
English keywords: wood utilization; forest industries; timber balance; wood supply
Abstract | View details | Full text in PDF | Author Info

The Finnish forest industries have doubled their use of wood raw material during the past two decades. The average annual overcut of 4.0 million m3 in 1960–64 has been turned into an average annual surplus of 2.7 million m3 in 1965–69. By 1974 industry’s requirements for domestic roundwood would increase by about 6.3 million m3, if all new capacity can be taken into full production. The MERA allowable cut, if realized, would leave a 1.5 million m3 annual surplus in the forest balance in 1974. Less intensive forestry programs would mean a 1.5 to 4.4 million m3 overcut in 1974.

The PDF includes a summary in English.

  • Linnamies, E-mail: ol@mm.unknown (email)
article id 4822, category Article
Eino Oinonen. (1970). Metsäkasvien kloonikasvustot maanteiden iän arvioimisen apuneuvoina. Silva Fennica vol. 4 no. 3 article id 4822. https://doi.org/10.14214/sf.a14611
English title: Clone stands of forest plants as aids for estimating the age of roads.
Original keywords: iänmääritys; kasvullinen lisääntyminen; kloonit; metsäkasvillisuus; maantiet; kielo; sananjalka; hietakastikka
English keywords: clones; Pteridium aquilinum; roads; country roads; chronological dating; forest vegetation; bracken fern; wood small reed; Calamagrostis epigeios; lily-of-the-valley; Convallaria majalis
Abstract | View details | Full text in PDF | Author Info

Clone stands of bracken fern (Pteridium aquilinum (L.) Kuhn.) wood small reed (Calamagrostis epigeios L.) and lily-of-the-valley (Convallaria majalis L.) are often partly split into two by the road, but often encountered also unilaterally on the roadside in the shape of a semicircle. The unilateral stands can be at times 20–30 m wide and they are sometimes solitary stands of the species. A method to define the age of the solitary stands of six plant species including bracken, wood small reed and lily-of-the-valley was developed in a series of earlier studies.

These stands can be used to define the time the road was built. Clones that are bound by the road unilaterally are younger than the road. If there are several unilateral clones and they are of different sizes, the road is older than the largest clone. When the road is skirted bilaterally only by clones divided by the road, it is younger than the smallest clone. When there are by the road side both unilaterally delimited clones and clones split by the road, the age of the road comes in the range of time determined by the age difference between the largest unilateral and smallest bilateral clone.

The PDF includes a summary in English.

  • Oinonen, E-mail: eo@mm.unknown (email)
article id 4809, category Article
N. A. Osara. (1969). Polttoaineiden ja puutalouden säännöstely Suomessa toisen maailmansodan aikana ja sen jälkeen. Silva Fennica vol. 3 no. 4 article id 4809. https://doi.org/10.14214/sf.a14597
English title: Government control of fuels and forestry in Finland during World War II.
Original keywords: metsätalous; toinen maailmansota; polttoaineet; Suomi; energianlähteet; tuontipolttoaineet; puu; puutuotteet; säännöstely; poikkeusolot
English keywords: wood products; forestry; Finland; wood; fuelwood; Second World War; fuels; imported fuels; regulation; reserve stocks
Abstract | View details | Full text in PDF | Author Info

As Finland has neither coal nor oil resources, it has had to resort to large-scale imports dependant on foreign relations and especially maritime connections. When the outbreak of World War II broke these connections, the state had to institute comprehensive controls and measures to ensure the supply of fuels. The present article deals with the measures taken by the authorities at that time.

Although the danger to Finland of interruption in fuel imports had been pointed out, the Finns had made hardly any preparations to manage on their own. In autumn 1939 there was no reserve stocks and particularly vulnerable was the question of motor fuels and lubricants.

When the Winter War ended in spring 1940, it was realised that special measures were needed. A law was enacted that concerned both the revival of production and regulation of consumption. For instance, every forest owner was notified of his share of the fuelwood logging. The wood processing industry had been accustomed to maintain stocks of wood covering two years’ requirements, but these inventories, too, were depleted by 1944. The law for safeguarding the supply of timber, enacted in early 1945, invested far-reaching powers in the authorities, and the logging plans were exceptionally large in 1945-47. Controls governing forestry and the forest industry were discontinued in 1947.

In Finland it is necessary to maintain a state of preparedness. This applies above all to fossil fuels and particularly oils.

The PDF includes a summary in English.

  • Osara, E-mail: no@mm.unknown (email)
article id 4806, category Article
Esko Leinonen, Pentti Rikkonen. (1969). Puutavaran kuorma- ja kuormaotantamittaus. Silva Fennica vol. 3 no. 4 article id 4806. https://doi.org/10.14214/sf.a14594
English title: Load and load sampling measurement of timber.
Original keywords: puutavara; puunkuljetus; puutavaranmittaus; kuormamittaus; otos
English keywords: timber scaling; load sampling; timber transportation; wood measurement; load measurement; measurement of roundwood
Abstract | View details | Full text in PDF | Author Info

Measurement of timber in a vehicle load or in a bundle is best performed at the mill where the measuring of large quantities can be mechanized and sampling is possible. Load measurement methods include calculation of the number of units, measurement of pile volume, weight scaling and determination of solid content in accordance with Archimedes principle by immersion in water. For some timber assortments, load measurement is sufficiently accurate and suitable unit of measure. The accuracy of load measurement can be increased or the result can be converted by sampling to a more appropriate unit of measure.

In load sampling measurement, a sample is taken from the population, and the desired more accurate measurement is made from the sample. The basic measurement for the whole population can be converted into the more accurate measuring unit by means of the ratio between it and the basic measure. Unit, pile and weight sampling can be used. The aim for pulpwood is to calculate the dry matter content without bark, which means that the amount of bark and the dry weight of wood must be determined by sampling.

The size of the sample depends on size of the population, variation of the ratio between the loads, and the accuracy required. As the quantity of wood to be measured decreases, sampling measurement will reduce the measuring costs by up to 80%. In addition, there is saving in costs by rationalization.

The PDF includes a summary in English.

  • Leinonen, E-mail: el@mm.unknown (email)
  • Rikkonen, E-mail: pr@mm.unknown
article id 4765, category Article
Jouko Einola. (1968). Raakapuuvaraston suunnittelusta ja tarkkailusta. Silva Fennica vol. 2 no. 2 article id 4765. https://doi.org/10.14214/sf.a14550
English title: On the planning and control of raw-wood inventories.
Original keywords: raakapuu; kustannukset; puuraaka-aine; varastot; toimitusvarmuus; varastojen hallinta
English keywords: inventory; costs; roundwood; raw material; raw wood; stock management; reliability of delivery
Abstract | View details | Full text in PDF | Author Info

The present study is an examination of the problems involved in raw-wood inventory from the viewpoint of business economics. The term inventory used here includes the standing timber marked for cutting as well as delivery contracts. The task of inventory is to buffer the differences in timing, locality, quantity and quality caused by purchase, production and delivery processes. The basic problem is concerned with profits.

The basic aim is to keep the inventory small. Its limits are determined by comparing the storage costs and costs of shortage. The costs may be decreased without risking the reliability of deliveries by technical development and road improvement, which also decrease dependence on the seasonal variation of harvesting of timber. A model based on present practices, statistics and practical experiences can be used to calculate different alternatives. The volume of purchases, felling, deliveries, transportation, and differences in quantities and transfer is used to estimate the target level of the inventory. It forms a forecast which the future performances can be compared to. In addition to monitoring turnover rate of the total inventory and capital tied to the inventory, also the exceptions in structure, time and quantity of the inventory and the factors changing it should be monitored. A special difficulty in timber inventory book-keeping are the continuous variations in the measured volumes even if no loss occurs.

The PDF includes a summary in English.

  • Einola, E-mail: je@mm.unknown (email)
article id 4746, category Article
Kari Löyttyniemi. (1967). Tikaskuoriaisesta (Trypodendron lineatum Oliv., Col., Scolytidae) kuorellisen havupuutavaran pilaajana. Silva Fennica vol. 1 no. 2 article id 4746. https://doi.org/10.14214/sf.a14456
English title: Damages caused to timber with bark by spruce ambrosia beetle (Trypodendron lineatum) in Finland.
Original keywords: hakkuut; puutavara; hyönteistuhot; hyönteiset; kaarnakuoriaiset; havutikaskuoriainen; varastointi; puutavarapinot
English keywords: bark beetles; roundwood; fellings; insect damage; spruce ambrosia beetle; Trypodendron lineatum; forest depot
Abstract | View details | Full text in PDF | Author Info

The paper studied the effect of felling time and conditions in the forest depot of timber to damages caused by spruce ambrosia beetle (Trypodendron lineatum Oliv.) to coniferous timber with bark, both experimentally and observing forest depots in Finland. Effects of fellings was studied by studying the abundance of the beetles in logging residue.

The results show that the spruce ambrosia beetles favour timber felled during the late autumn and winter, stored in a shaded place in the forest. In addition, new spruce stumps maintain and increase the beetle population. Fellings in the forest will increase population during the next year and cause damages in forest depot of timber nearby, because the insect breeds in the stumps. The experiments showed that it is possible to diminish the damages caused by the beetle to timber with bark by spraying with insecticides, and timing the fellings and transport of timber so that there is no timber in the forest in the spring during the time when the insect swarms.

The PDF includes a summary in German.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4734, category Article
Yrjö Kangas. (1966). Valtion metsien hakkuupoistuma ja sen rakenne : Vuosiin 1954-1958 kohdistuva selvittely. Silva Fennica no. 120 article id 4734. https://doi.org/10.14214/sf.a14292
English title: Felling volume and its structure in the Finnish State Forests in 1954-1958 .
Original keywords: hakkuut; valtionmetsät; hakkuumäärät; jätepuu; 1954-1958; hakkuupoistuma; hakkuukertymä
English keywords: Finland; state forests; waste wood; loggings; merchantable timber; felling volume
Abstract | View details | Full text in PDF | Author Info

The purpose of this investigation was to study the felling volume and its structure in the State forests of Finland. Special attention was paid on the proportion of waste wood within the felling volume. This information was in demand for the general plan of the State forests that was being prepared at the same time. The survey was performed using a sampling method, and it represented the districts in the northernmost Finland, Ostrobothnia, Eastern Finland and Western Finland of the Forest Services.

The proportion of merchantable timber of the total felling volume was lowest in the northernmost Finland, less than 2/3 of the total cut. In Ostrobothnia the share was ¾, Eastern Finland 4/5 and in Western Finland 5/6. When the tree species were compared, the proportion of waste wood was largest in broadleaved trees, especially in the Northern Finland, while for Scots pine it was lowest. For Norway spruce the share of merchantable timber is markedly lower in the northernmost part of the country, where, for instance, decay increases the proportion of waste wood. For birch, demand of wood influences most the proportion of waste wood.

In general, the proportion of waste wood and merchantable timber in the felling volume was influenced by changes in the demand of timber, structure of the stands, and the felling method. The demand of the timber assortment affects most in the amount of waste wood. The more valuable the timber assortment is, the less waste wood is left in the cutting area.

The PDF includes a summary in German.

  • Kangas, E-mail: yk@mm.unknown (email)
article id 4729, category Article
Puutavaranmittauskomitea. (1966). Puutavaranmittauskomitean mietintö : Osamietintö I. Silva Fennica no. 118 article id 4729. https://doi.org/10.14214/sf.a14287
English title: Report of timber scaling committee.
Original keywords: komiteanmietinnöt; puukauppa; puutavaranmittaus; puutavaranmittauslaki
English keywords: legislation; wood sales; timber sales; timber scaling; Timber Scaling Act
Abstract | View details | Full text in PDF | Author Info

A Timber Scaling Committee was appointed by the Government of Finland in 1959, commissioned with the regulations concerning the scaling of timber and to draw a proposal for their amendments. The commission suggest revision of the regulations in their entire extent. The largest alterations should be made in the act which incorporates the provisions concerning the actual technical methods of procedure in measuring. Thus, also amendments were also posed for the Timber Scaling Law and the law concerning the scaling of timber for the purpose of paying wages.

The inclusion of the setting of the grades and quantities are considered important, since most of the disagreements occurring in measuring are concerned with quality of the timber. Inside of the sphere of application of the law would also be settling of the problems of the quality, and the measuring procedure, also when measuring for the purpose of paying wages.

According to the bill, the necessary number of official scalers and scaling boards would be appointed. The duties of the present officers would be changed. In the boards would be presented sellers, buyers, employers and employees besides the chairman. The freedom of contract in the scaling of timber will be preserved from the present law.

The report includes a bill for the Timber scaling Act, a draft for the timber scaling act, and a draft for an act which includes the timber scaling rules.

The PDF includes a summary in English.

  • Puutavaranmittauskomitea, E-mail:
article id 4728, category Article
Yrjö Roitto. (1966). Polttopuun käyttö Euroopassa vv. 1950.1960 sekä mahdollisuudet polttopuun teolliseen käyttöön v. 1975. Silva Fennica no. 117 article id 4728. https://doi.org/10.14214/sf.a14286
English title: Use of fuel wood in Europe in 1950-60 and possibilities of converting fuelwood to industrial uses by 1975.
Original keywords: metsäteollisuus; polttopuu; raaka-aine; Eurooppa
English keywords: firewood; Europe; fuel wood; wood consumption; 1950-1960; forest industries; raw material
Abstract | View details | Full text in PDF | Author Info

According to the statistics, the fuel wood consumption in Europe has declined since 1925/1929, when the total fuel wood consumption was 144 million m3. In 1960 the consumption was 108 million m3. Because of insufficient statistics in the early years, the drop may even be larger than shown by the figures. The aim of this paper is to assess what part of European fuel wood removals in 1960 could be used for industrial purposes by 1975.

It was estimated that in 1975 the use of fuel wood in Europe will be about 45–55 million m3 less than in 1960 and about 10 million m3 of this amount will consist of coniferous species. It is believed that about 45 million m3 could be transferred to industrial use by 1975, and 55 million m3 is supposed to be the maximum reduction achievable by 1975. The estimates are based on the revised European fuel wood removal figures.

The new European timber trends and prospects study reveals a shortage of small-sized coniferous wood of about 25–43 million m3, depending on whether the exports from Europe are curtailed or not. The decrease of coniferous fuel wood of 10 million m3 could almost entirely be transferred for the use of industry.

A more important question is, is there demand for the extra small-size broadleaved wood. It is important to note that there is no longer any technical limitations on the use of this kind of wood for producing pulp, paper paperboard and wood-based panel products.

Fuelwood is often collected by the farmer and used near the farm. If the wood is to be used in the industry, harvesting and transport costs need to be decreased. However, productivity of the logging and transportation may be significantly improved by cutting the trees into longer lengths and professional harvesting. About 40% of the potential transfer of fuelwood to industrial uses is concentrated in Finland (7 million m3), France (5 million m3), and Italy (7 million m3). Other countries with significant potential shifts could be Romania, Spain and Yugoslavia.

The PDF includes a summary in French, German, Dutch, Russian and Finnish.

  • Roitto, E-mail: yr@mm.unknown (email)
article id 4724, category Article
Seppo Ervasti, Lauri Heikinheimo, Viljo Holopainen, Kullervo Kuusela, Gustaf Sirén. (1965). The development of Finland's forests in 1964-2000. Silva Fennica no. 117 article id 4724. https://doi.org/10.14214/sf.a14282
Original keywords: hakkuut; metsänhoito; metsätalous; puunkäyttö; metsäteollisuus; metsävarat; Suomi; ennusteet; puuntarve
English keywords: forest management; Finland; forest resources; allowable cut; wood utilization; 1964-2000; forecast; removal
Abstract | View details | Full text in PDF | Author Info

The Economic Council asked Heikinheimo, Holopainen and Kuusela to prepare a report on the development of Finland’s forest resources up to the beginning of the next century. The expansion of forest industry beyond the level foreseen in earlier forecasts, the large-scale removal and neglect of the basic improvements required have weakened the condition of the wood production to such an extent that extensive measures are needed to ensure the continuity of the supply of wood. The results of the calculations are formed in three separately analysed alternatives.

Alternative I: Realisation of the Teho programme and the removal corresponding to it. The development of the growing stock according to the programme would only permit a cut amounting to an annual drain of ca. 51 million m3 up to the year 2000. After that it would be possible gradually to increase the removal. This drain would not itself to utilise fully the already existing production capacity of the industry.

Alternative II: Consequences of the predicted removal if the Teho programme is realised as such. The wood utilization forecast based on the premises given to the team show that the annual drain will grow in 1964–1975 from 52 to 58 million m3, and thereafter by 0.5% annually. This would lead to over-cutting, and exhaust the present growing stock by the turn of the century. If annual total drain of ca. 58 million m3 would after 1975 be sufficient, exhaustion of the growing stock would be postponed for 4–5 years.

Alternative III. Teho programme expanded in conformity with the removal forecast. A new programme is proposed, which includes, among others, large scale fertilization of fully grown firm forest land at about the rate of 100,000 ha/year, intensified artificial regeneration, assurance of the supply of planting stock and seed, increase of forest drainage from the present 155,000 to 250,000 ha/year by 1970, site preparation of the cutting areas for artificial regeneration, increase of tending or seeding stands to 300,000 ha/year, replacement of fuelwood by other fuels, increase of wood import and new forest roads.

  • Ervasti, E-mail: se@mm.unknown (email)
  • Heikinheimo, E-mail: lh@mm.unknown
  • Holopainen, E-mail: vh@mm.unknown
  • Kuusela, E-mail: kk@mm.unknown
  • Sirén, E-mail: gs@mm.unknown
article id 4718, category Article
Ilmo Rinkinen. (1964). Suomen sahateollisuuden jätepuu. Jätepuun käyttöä ja sen edullisuutta koskeva tutkimus. Silva Fennica no. 115 article id 4718. https://doi.org/10.14214/sf.a14277
English title: Waste wood of the Finnish sawmill industry. A study of the use of waste wood and its profitability.
Original keywords: sahateollisuus; jätepuu; sahat; raaka-aine; selluteollisuus; kierrätys
English keywords: recycling; waste wood; sawmills; sawmill industry; raw materia; pulp industry
Abstract | View details | Full text in PDF | Author Info

The purpose of this investigation was to construct a procedure for measuring the profitability of the use of waste wood. The average price a sawmill gets from the waste wood depends, on the amount of use compared with the waste wood output, and on the composition of waste wood. Production of different kinds of waste wood presupposes investments, therefore, the size of a sawmill, in addition to its location, affects the composition. The data was collected by mailing a questionnaire through the central organizations of the sawmill industry in 1959.

The amount of waste wood per standard of sawn wood increases with the size of the sawmill. Because small sawmills cannot generally use or sell their waste wood, they strive at using the raw material effectively. In addition, they produce much rough-edged sawn wood, and sorting is not as strict as at large sawmills. They also leave their sawn wood untrimmed.

Finland’s pulp industry has expanded significantly since 1958. This has increased the need of raw wood, and the demand of sawmill waste. An additional data collected showed that in 1958 there was about 150 and in 1963 about 200 sawmills delivering waste wood to the forest industry. The amount of waste wood used as raw material compared with the total waste wood utilization had increased about 10% during the period. The production of cellulose chips became profitable when the annual output of sawn wood of a sawmill exceeded 1,000-2,000 stds. The size structure of the sawmills affects the regional usage of the waste wood.

The PDF includes a summary in English.

  • Rinkinen, E-mail: ir@mm.unknown (email)
article id 4701, category Article
Veijo Heiskanen. (1961). Tutkimuksia koivuhalkojen painosta ja kosteudesta. Silva Fennica no. 108 article id 4701. https://doi.org/10.14214/sf.a9136
English title: Studies on the weight and moisture of split birch fuel wood.
Original keywords: polttopuu; koivu; halot; lämpöarvo; kosteusprosentti; kuivapaino
English keywords: birch; firewood; moisture content; fuel wood; heat value; dry weight; split billet
Abstract | View details | Full text in PDF | Author Info

The purpose of this investigation is to examine the weight and moisture of split birch fuel wood and to calculate its heat values. The weight was measured of 255 truck loads in six different locations during the winter 1959–1960. Moisture analysis was made of sample specimens collected from the loads.

The dry matter weight of the birch fuel wood was in an average 333 kg/m3 piled measure. The lowest measured weight was 319 and the highest 341 kg/m3 piled measure. The moisture content in the different parts of the pile varies distinctly. Driest wood is found in the middle of the pile. Wood in the top and bottom of the pile have about similar moisture content.

The manner of storage influences the drying process. The moisture content of open piles is 20.5%, of paper-covered piles 19.9% and roofed multiple-piles of split fuel wood 19.3%. The 2-year-old piles were dryer than 1-year-old ones. Higher percentages (25% and 20 %, respectively) than those measured in the study, are recommended for practical use. The heat value of the wood stored in a pile was in average 1,435 Mcal/m3 piled measure, and 1,455 Mcal/m3 piled measure sampled from a truck load.

The PDF includes a summary in English.

  • Heiskanen, E-mail: vh@mm.unknown (email)
article id 4694, category Article
Seppo Ervasti. (1960). Metsäntuotteet Ison-Britannian rakennusaineiden mainonnassa. Silva Fennica no. 104 article id 4694. https://doi.org/10.14214/sf.a9133
English title: The position of forest products in advertising of building materials in Great Britain.
Original keywords: Suomi; Iso-Britannia; rakennustuotteet; markkinointi; mainonta
English keywords: Finland; building materials; Great Britain; marketing; advertising; sawn goods; wood-based panels
Abstract | View details | Full text in PDF | Author Info

This paper concentrates on analysing advertising of building materials used in residential, agricultural and factory building, power station construction, warehouse building and the joinery industry in Great Britain, concentrating on advertising to consumers, including architects, engineers, building entrepreneurs, farmers and do-it-yourself practitioners. The material is based on questionnaires answered by 8 professionals of the field, and assessment of two leading English paper in the field of construction in January 1 – June 30, 1959.

It was concluded that forest products were clearly less advertised than other building materials. The unweight average degree of advertising of all forest products was. 1.7, while the score was 2.6 for other materials. Of the different forest products stand out advertising of plywood and sawn good. The most extensively advertised materials were metals, concrete and cement, and some covering materials. Forest products accounted only ¼ of the advertising space in the publications.

The most important media used in advertising building materials were trade journals, calendars and yearbooks, courses and lectures, exhibitions and fares and direct advertising. The most important audience of advertising were architects, followed by the entrepreneurs. It is suggested that the advertising of Finnish products in Great Britain might be best organized by placing it in the hands of two organizations: the sales organisation and a separate body for advertising. The producers would manage the advertising of individual brands to sales level, while the other levels (agents, importers, merchants) would manage the joint advertising of the forest products to the lower sales levels and consumers. A Finnish market research and information offices might be established in Great Britain.

The PDF includes a summary in Finnish.

  • Ervasti, E-mail: se@mm.unknown (email)
article id 4680, category Article
Pohjois-Suomen uitto-olojen järjestelykomitea. (1959). Pohjois-Suomen uitto-olojen järjestelykomitean mietintö. Silva Fennica no. 102 article id 4680. https://doi.org/10.14214/sf.a14123
English title: Report of the organizing committee for timber floating in Northern Finland.
Original keywords: Pohjois-Suomi; uitto; komiteanmietinnöt; puunkuljetus; uittoväylät; vesivoima
English keywords: northern Finland; floating; wood transport; timber transport; floating channels; hydroelectric power; hydroelectric power plants
Abstract | View details | Full text in PDF | Author Info

Hydroelectric plants are being planned or already built in Northern Finland. The complete terracing and regulation of watercourses necessary for the power plants will mean great changes in floating conditions and hence for forestry, for which floating is the principal means of transport. Consequently, the Cabinet appointed a committee in 1958 to ascertain the economic, technical and legislative questions connected with timber transport in the area.

The committee has found that about half of the country’s forest area and two thirds of its water power resources are situated in Northern Finland. A prerequisite for the wise utilization of the forest in Northern Finland is an increase in fellings. This can only be put into effect by improving the means of transport, especially the floating channels. The financing required by the organization of floating connected with the building of the hydroelectric power plants amounts to about 10,000 million marks over a period of 20 years.

The committee has suggested that an advisory committee on floating should be established. Its most important task would be to try to produce a general programme for the organization of floating under the changed conditions, and that the State should participate in the expenditure caused by the organization as regards the capital investment needed for changing over to bundle floating.

The PDF includes a summary in English.

  • Pohjois-Suomen uitto-olojen järjestelykomitea, E-mail:
article id 4686, category Article
Kalle Putkisto. (1959). Puutavaran valmistus- ja metsäkuljetustöiden koneellistumisen vaikutus metsätalouden työvoiman tarpeeseen : ennuste vuoteen 1972. Silva Fennica no. 101 article id 4686. https://doi.org/10.14214/sf.a9127
English title: Effect of the mechanization of timber preparation and forest transport on the need of labour force in forestry. Prognosis up to 1972.
Original keywords: metsätalous; metsätyö; työvoima; puunkorjuu; koneellistuminen; ennusteet; metsäkuljetus
English keywords: forestry; forest transport; mechanization; wood harvesting; fellings; workforce; forest work; prognosis
Abstract | View details | Full text in PDF | Author Info

In 1957 the annual cuttings in Finland were 40.2 million m3 without bark. The aim of the study was to estimate the rate of mechanization of harvesting of timber in Finland, and make a prediction of the state of mechanization by 1972. According to the study, harvesting and transportation of the felling volume in 1957 would have required about 25.5 million working hours. Mechanization of forest work has decreased it only by 0.32 million working hours. The profitability of forest work has improved in 1950s, which is mainly due to changes in harvesting, such as shifting to longer lengths of pulpwood and props and cutting unbarked timber.
The study predicts that in 1972 it will take 14.8 million working hours to harvest and 5.4 million working hours to transport a corresponding felling volume as in 1957. However, a new way of producing timber or a working method of wood may change the picture completely. Reduction in harvesting expenses through mechanization may lead to diminishing the minimum diameter of logs, which affects profitability of work. It is also probable that mechanization of wood transportation will lead to working sites with longer distances of forest transportation. Also, industry using wood as raw material will also obviously expand.

The article includes a summary in English.

  • Putkisto, E-mail: kp@mm.unknown (email)
article id 4671, category Article
O. Leskinen, O. Vuorelainen. (1957). Tutkimus keskuslämmityslaitosten eri polttoaineiden taloudellisen käytön alueellisesta jakautumisesta Suomessa. Silva Fennica no. 93 article id 4671. https://doi.org/10.14214/sf.a9118
English title: A study on regional differences in economical use of different fuels in central heating boilers in Finland.
Original keywords: polttopuu; hiili; polttoaineet; öljy; Suomi; kustannukset; lämmituskustannukset; lämmitslaitteet; keskuslämmitys
English keywords: fuelwood; fuel; coal; coke; oil; central heating; boilers; heating apparatus; heater
Abstract | View details | Full text in PDF | Author Info

The purpose of the study was to find out the most economical fuel for central heating boilers in different parts of Finland. The most common central heating fuels and boilers used in Finland were compared in the study.

The present consumption of different fuels and the regional distribution of the boilers of a few main types was investigated. The costs were calculated according to the costs level of February 1957. To be able to compare the costs, both variable costs and fixed costs were calculated. The heat output produced annually in the different boilers was studied to divide the fixed costs into costs per heat unit.

Comparison of the total costs per heat unit showed that cost of wood or imported fuels (oil, coke, coal etc.) was about on the same level in the coastal areas close to import harbours, but wood was the cheapest fuel for central heating in inland.

The article includes an abstract in English.

  • Leskinen, E-mail: ol@mm.unknown (email)
  • Vuorelainen, E-mail: ov@mm.unknown
article id 4659, category Article
P. Piepponen. (1957). Arvo- ja rakennuspuiden merkitseminen asutustilojen metsissä. Silva Fennica no. 92 article id 4659. https://doi.org/10.14214/sf.a14060
English title: Marking of construction and other valuable timber in the forests of settlement farms.
Original keywords: hakkuut; metsäopetus; asutustoiminta; asutuslaki; jatkokoulutus; asutustilat; puunkorjuu; yksityismetsälaki
English keywords: valuable timber; wood harvesting; fellings; forest education; settlement; settlement farms; Land Settlement Decree
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 92 includes presentations held in 1956 in the 8th professional development courses, arranged for forest officers working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

Fellings of valuable timber in the forests to be surrendered for settlement farms have been discussed widely in Finland. This presentation describes the effects of the new section in the Land Settlement Decree and new directions given by Central Forestry Association Tapio based on the decree. According to the directions, the fellings have to follow legislation concerning other fellings in private forests. The felling of all large, valuable timber, as has previously been the custom in settlement farm forests, does not follow this principle.

  • Piepponen, E-mail: pp@mm.unknown (email)
article id 4646, category Article
Paavo Yli-Vakkuri. (1955). Tutkimuksia metsänhoitolautakuntien ja -yhdistysten leimaustoiminnan kehityksestä. Silva Fennica no. 87 article id 4646. https://doi.org/10.14214/sf.a9108
English title: Studies on crop marking of District Forestry Boards and Forest Management Associations.
Original keywords: metsänhoito; yksityismetsät; puukauppa; tukkipuu; leimaus; metsälautakunnat; metsänhoitoyhdistykset; pinotavara
English keywords: logs; silviculture; private forests; timber sales; marking of timber; stacked wood; District Forestry Boards; Forest Management Associations
Abstract | View details | Full text in PDF | Author Info

Wood demand and practices in the marking of trees for cutting have affected the silvicultural state of the forests of Finland in the early 1900s. The aim of the study was to study the development of timber sales and the marking of trees for logging, with a special emphasis on variation in the volume of the sales and assortment range. The study is based on statistics of the District Forestry Boards and Forest Management Associations about timber marked for cutting in 1931-1953.

The professionals in the District Forestry Boards and Forest Management Associations have marked annually in average 9 million stems of heavy timber and about 7 million m3 of stacked wood for sales. The volume  follows business cycles, the changes in the volume of stacked wood being larger than of heavy timber. When demand was high, the number of professional workers limited the supply of wood. There were large differences in the volumes marked within the country. The share of small diameter stacked wood has increased since 1930s compared to heavy timber.

The article includes a summary in German.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 4642, category Article
Einar Maliniemi. (1954). Tilastollinen tutkimus sahapuiden hakkuusta ja ajosta Perä-Pohjolassa. Silva Fennica no. 82 article id 4642. https://doi.org/10.14214/sf.a9103
English title: Statistical analysis on felling and haulage of sawlogs in Perä-Pohjola in Northern Finland.
Original keywords: Pohjois-Suomi; Perä-Pohjola; metsätyö; puunkuljetus; palkkaus; tukkipuu; puunkorjuu; työntutkimus
English keywords: northern Finland; work study; timber harvesting; sawlogs; haulage; forest work; wages; wood transportation
Abstract | View details | Full text in PDF | Author Info

The wages of logging and haulage has been dependent on the decisions of foremen. The aim of this study was to provide better insight on how working conditions in a logging site affect productivity of the work. Six working sites operated by Forest Service, Veitsiluoto Oy and Kemi Oy in the communes of Salla, Muonio and Kolari in Lapland were studied. The forests in the area were mostly Scots pine (Pinus sylvestris L.).

The effect of average volume of the stems, the average daily haulage over distances of various lengths, density of the stand and shape of the stem on effectivity was calculated. The size of the team was of considerable importance to the felling and haulage result in the Northern Finland where the feller assists in loading of the logs. One of the aims of the study was to find out what size of team is most advantageous for each haulage distance. The results show the optimum distance of haulage for teams of different sizes.

The article includes a summary in English.

  • Maliniemi, E-mail: em@mm.unknown (email)
article id 4624, category Article
Polttoainekomitea. (1952). Polttoainekysymys vuonna 1951 : polttoainekomitean mietintö. Silva Fennica no. 74 article id 4624. https://doi.org/10.14214/sf.a9096
English title: The fuel question in Finland in 1951.
Original keywords: polttopuu; komiteanmietinnöt; hiili; polttoaineet; öljy; polttoturve; tuonti
English keywords: firewood; fuel; coal; coke; fuel peat; oil; fuel demand; fuel import
Abstract | View details | Full text in PDF | Author Info

The government of Finland appointed a committee to make a suggestion of measures to be taken to arrange fuel supply during the heating season. The committee drafted also a plan to regulate and govern the fuel economy.

The committee estimated that the total consumption of coal, coke, firewood, waste wood and fuel peat, converted into pine firewood increased from 33.8 million eu.m in piled measure in heating period of 1952-53 to 42.9 million in 1955-56. According to the report, the demand of fuel is met increasingly through imported fuels, such as coal, coke and oil. The change is mainly due by their lower price and technically easy handling compared to domestic fuels.

The committee suggests that the production of domestic fuels, peat and firewood, should be increased and rationalized. In addition, financial support should be targeted to construct hydroelectric plants. Fuel peat industry should be developed further. The use of oil should be promoted, and boilers able to use different kinds of fuel should be constructed. To be prepared in changes in international situation, stocks of fuel are needed.

  • Polttoainekomitea, E-mail:
article id 4623, category Article
Metsätalouskomitea. (1952). Puun maakuljetusolojen kehittäminen : vuoden 1949 metsätalouskomitean mietintö N:o 1. Silva Fennica no. 73 article id 4623. https://doi.org/10.14214/sf.a9095
English title: Development of land transportation of wood.
Original keywords: komiteanmietinnöt; puunkuljetus; tienrakennus; metsätiet; kuljetus; infrastruktuuri; rautatiet
English keywords: forest road; road construction; forest roads; transportation; wood transportation; railroad
Abstract | View details | Full text in PDF | Author Info

The government of Finland appointed in1949 a committee to draft a program to promote forestry and increase the production of forests in the immediate future. The committee regarded promotion of transportation of roundwood and fuel wood as the most urgent question of the assignment. A separate committee was assigned to give a report on floating.

The report gives a summary of timber transportation facilities. The importance of land transport, especially truck transport, has grown. This has influenced other means of long-distance transport, such as railways and floating. Building of truck roads can bring large areas of presently unaccessible forests accessible for forest industry.

The committee suggest improvements in road legislation. Improvements needed in the road system for better timber transport facilities are outlined. The committee gives a detailed list of roads, compiled by area. The total length of forest roads to be constructed is 5,584 km, and the estimated cost 6,702 million marks. Railroads would be built 1,453 km at the cost of 35,745 million marks.

The article includes an abstract in English.

  • Metsätalouskomitea, E-mail:
article id 4612, category Article
Veijo Heiskanen. (1951). Mäntysahatukkien laadun mukaisista arvosuhteista. Silva Fennica no. 69 article id 4612. https://doi.org/10.14214/sf.a14008
English title: Value grading of Scots pine saw logs.
Original keywords: metsäopetus; mänty; metsänhoitajien jatkokurssit; sahatavara; jatkokoulutus; sahatukit; laatuluokitus; hinnoittelu
English keywords: Pinus sylvestris; Scots pine; saw logs; sawn timber; forest education; quality grading; sawn wood; timber grading
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 69 includes presentations held in 1948-1950 in the fourth professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

Quality grading has been rarely used in pricing of saw logs due to lack of knowledge on how the quality of logs affects the value of the sawn wood. This presentation discusses the subject based on unpublished data professor Ilmari Vuoristo collected in 1930s on effects of timber grading on the quality and value of sawn wood. The quality classification developed by professor Vuoristo is presented.

  • Heiskanen, E-mail: vh@mm.unknown (email)
article id 4605, category Article
Arvo Kivelä. (1951). Pohjois-Suomen uitot ja niiden tehoa haittaavat tekijät. Silva Fennica no. 69 article id 4605. https://doi.org/10.14214/sf.a14001
English title: Floating in Northern Finland and factors reducing its efficiency.
Original keywords: Pohjois-Suomi; uitto; puunkuljetus; uittoväylät; vesikuljetus
English keywords: northern Finland; floating; wood transportation; floating channels; water transportation
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 69 includes presentations held in 1948-1950 in the fourth professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

Floating channels of Northern Finland have been unable to fulfill all the needs of wood transportation of the area. This presentation presents diferent ways to improve the efficiency of floating by improving working methods and the channels, and thus decreasing costs of wood transportation.

  • Kivelä, E-mail: ak@mm.unknown (email)
article id 4599, category Article
Polttoainekomitea. (1950). Polttoainekysymys vuonna 1949 : polttoainekomitean mietintö. Silva Fennica no. 67 article id 4599. https://doi.org/10.14214/sf.a9090
English title: The fuel question in 1949.
Original keywords: hakkuut; metsänhoito; polttopuu; komiteanmietinnöt; hiili; polttoaine; pieniläpimittainen puu; polttopuun kysyntä; työllisyys; maaseutu
English keywords: silviculture; fuelwood; fuel; employment; fellings; coal; rural population; coke; small-sized wood; demand
Abstract | View details | Full text in PDF | Author Info

Fuel shortage during and after the Second World War compelled the Government of Finland to improve the fuel supply. In 1948 the Government appointed a Committee to draft a proposal on use of domestic and imported fuels. Special attention was placed on how to develop use of peat as fuel.

In rural districts, firewood billets and waste wood accounted for 45% of fuel consumption. For other users than the rural population, coal and coke consisted 25%, industrial waste wood 11% and billets 18% of the total consumption in 1938. After the war the use of coal and coke increased and the use of billets decreased.

Due to the decreased demand of billets, their price in the towns fell lower than the production and transport costs from the most remote areas where the wood was harvested. The demand for small sized timber is important for silvicultural reasons, and wood harvesting creates jobs for the rural population, therefore, the Committee proposes that the state supports the production of billets. This could be done by improving the effectiveness of firewood loggings, and by building truck roads and railways.

Small-sized birch is used predominantly as fuel. The Committee considers the growing stock of birch to be the largest unutilized wood reserve. Supported by technological research, it may become a new raw material for sulphate cellulose industry. Use of industrial waste wood as fuel and improvement of heating equipment would improve the competitiveness of fuelwood and peat against other fuels. For the possible interruptions in imports, stocks of foreign fuels should be maintained.

The article includes a summary in English.

  • Polttoainekomitea, E-mail:
article id 4595, category Article
Lauri Silvàn. (1948). Metsäautoteiden rakentaminen. Silva Fennica no. 64 article id 4595. https://doi.org/10.14214/sf.a13997
English title: Building of forest lorry roads.
Original keywords: metsäopetus; puunkuljetus; metsänhoitajien jatkokurssit; tienrakennus; jatkokoulutus; metsätiet; metsäautotie
English keywords: forest education; road construction; wood transport; forest roads; forest lorry roads
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation discusses cost-effectiveness of building forest lorry roads to expand the availability of timber in state forests, and gives examples of calculating costs of building a road.

  • Silvàn, E-mail: ls@mm.unknown (email)
article id 4591, category Article
Aarne Anttila. (1948). Kustannusten arvioiminen hankintahakkuissa. Silva Fennica no. 64 article id 4591. https://doi.org/10.14214/sf.a13993
English title: Estimation of costs of delivery loggings.
Original keywords: valtionmetsät; Metsähallitus; metsäopetus; metsänhoitajien jatkokurssit; puukauppa; jatkokoulutus; hankintahakkuut; puun kuljetus; hakkuukustannukset
English keywords: timber harvesting; Forest Service; forest education; state forests; timber sales; sale at delivered price; cost of harvesting; wood transportation
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica. 

This presentation describes budgeting of costs of delivery loggings, which have been at times underestimated in the practical forestry in the state forests.

  • Anttila, E-mail: aa@mm.unknown (email)
article id 4590, category Article
E. A. Sopanen. (1948). Hankintatöiden paikallinen organisointi. Silva Fennica no. 64 article id 4590. https://doi.org/10.14214/sf.a13992
English title: Organizing delivery loggings locally.
Original keywords: valtionmetsät; Metsähallitus; metsäopetus; metsänhoitajien jatkokurssit; metsähallinto; puukauppa; jatkokoulutus; hankintahakkuut
English keywords: wood harvesting; Forest Service; forest education; state forests; timber sales; sale at delivered price; delivery loggings
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation outlines the history of timber sales at delivered price made in state forests, and describes good practices to arrange timber harvesting locally.

  • Sopanen, E-mail: es@mm.unknown (email)
article id 4581, category Article
V. Lihtonen. (1945). Metsäteollisuusyhtiöiden metsistä ja niiden hakkuista. Silva Fennica no. 61 article id 4581. https://doi.org/10.14214/sf.a9085
English title: Forests of woodworking industry and the fellings carried out in them.
Original keywords: hakkuut; polttopuu; yksityismetsät; puun kysyntä; puukauppa; sota-aika; metsäteollisuusyritykset; toinen maailmansota
English keywords: firewood; forest industry; wood harvesting; fellings; private forests; wood demand; timber sales; world war II
Abstract | View details | Full text in PDF | Author Info

The aim of this treatise is to describe forests owned by timber companies, their area and position, the quality of forests, the condition of the forests, and fellings carried out during the World War II.

Area of the company-owned forest was 1,95 million hectares, 1,64 million hectares of which was productive and 0,31 hectares inferior forest soil, not including the areas lost after the war. Most of the forests were situated in remote regions. Average volume of the tree stands was slightly larger than in farm-owned forests. Fellings counted for 84% of the growth of the forests.

During the war  the state set felling quotas for both company, private and state forests. It was widely discussed how well they were met by the different owner groups. According to the statistics, the companies had followed relatively closely their cutting plans in peace years. Cuttings were highest in 1939, when the war begun. In the war years 1940-43, lack of workforce, horses and cars for transport complicated logging. The fellings increased again during truce after Winter War. Especially demand for small timber increased during the war. Felling of firewood increased in all the owner groups, in particular in the private forests that were situated near settlements. in general fellings were higher in forests that were easiest to reach.

During the war the companies acquired timber more from their own forests. The fellings from company forests were in war years 70% of those in peace years. The article concludes that companies fulfilled the requirements as well as it was possible in the circumstances.

The article includes an abstract in English.

  • Lihtonen, E-mail: vl@mm.unknown (email)
article id 4580, category Article
Johannes Virolainen. (1943). Karjalan kannaksen metsätaloudesta ja sen merkityksestä alueen pienviljelijöiden ansiotaloudessa. Silva Fennica no. 60 article id 4580. https://doi.org/10.14214/sf.a9084
English title: Forestry in the Karelian isthmus and its influence on the economy of small farms.
Original keywords: metsätalous; yksityismetsät; puukauppa; maatilat; metsätulot; liiketalous; maatilametsätalous; Karjalan kannas; pientilat
English keywords: forestry; economics; private forests; agriculture; farms; timber sales; small farms; forest income; wood trade; Karelian isthmus
Abstract | View details | Full text in PDF | Author Info

The article is based on studies made in the Karelian isthmus in 1936-1938 before the World War II broke in 1939. Further studies were not possible after the war when the area was handed over to Soviet Union. Economic data of agriculture and forestry of the farms had mostly been regarded separately in the early economic studies of small farms in Finland. This survey aimed at studying influence of forestry in the economy of a small farm. 141 farms were included in a more detailed survey.

Forestry accounted for in average 38% of total income of the farms in 1937-1938. The farms had sold wood often, the amounts being often small. Good transport connections in the area facilitated the sales. Over 70% were sales at delivered price, and about half of the wood was small-sized timber. According to the results of the survey, forestry was important for the small farms in Karelian isthmus. The farmers could not have made a living without the forests. Hoveter, the farms had had to overuse the forest resources. The wood resources decreased by 18-22% in 1922-1938. They were, however, at the same level as in average in Finland in 1938.

The article includes an abstract in German.

  • Virolainen, E-mail: jv@mm.unknown (email)
article id 4556, category Article
Olli Heikinheimo. (1939). Metsätalous ja matkailu. Silva Fennica no. 52 article id 4556. https://doi.org/10.14214/sf.a13963
English title: Forestry and tourism.
Original keywords: hakkuut; metsätalous; metsäopetus; metsänhoitajien jatkokurssit; jatkokoulutus; matkailu; maisemanhoito; virkistyskäyttö; maisema; luontomatkailu
English keywords: tourism; landscape; wood harvesting; fellings; forest education; professional development courses; nature tourism; landscape management; recreation
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes nature turism and recreation in Finland, how timber harvesting and nature conservation affect tourism and ways to adjust fellings to tourism.

  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 4555, category Article
O. Seppänen. (1939). Puutavaran autokuljetuksesta ja sen merkityksestä valtion metsätaloudessa. Silva Fennica no. 52 article id 4555. https://doi.org/10.14214/sf.a13962
English title: Car transportation of roundwood and its significance to forestry in the state forests.
Original keywords: valtionmetsät; Metsähallitus; metsäopetus; puunkuljetus; metsänhoitajien jatkokurssit; jatkokoulutus; metsätiet; autokuljetus; tiet
English keywords: Forest Service; forest education; professional development courses; stateforests; wood transport; timber transport; transportation of roundwood; road transport; forest roads
Abstract | View details | Full text in PDF | Author Info

Silva Fennica issue 52 includes presentations held in professional development courses, arranged for foresters working in public administration in 1938. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes the history of road transport of timber in Finland and discusses its significance and potential to forestry in the state forests.

  • Seppänen, E-mail: os@mm.unknown (email)
article id 4571, category Article
Tauno Lampimäki. (1939). Nautakarjan laiduntamisesta metsämailla. Silva Fennica no. 50 article id 4571. https://doi.org/10.14214/sf.a9074
English title: Grazing of cattle in forest land.
Original keywords: metsätalous; taimettuminen; metsänuudistuminen; laiduntaminen; laitumet; karja; karjatalous; pintakasvillisuus; taimet; taimituhot; metsälaidun
English keywords: regeneration; forestry; ground vegetation; tree seedlings; grazing; cattle; animal husbandry; woodland pasture
Abstract | View details | Full text in PDF | Author Info

Finland has a long tradition of grazing cattle in the forests and common land. There are also reports of degradation of forests by grazing already in 1600th century. The aim of the survey was to study which positive and negative effects grazing has in forests.

The study concludes that grazing has caused considerable economic losses through damages to forests. In addition, woodland pastures cannot give the yields required in modern animal husbandry. The quality of woodland pastures have decreased after the woodlands used in slash and burn culture have become wooded.

Grazing has also some positive effects to forests. It increases the diversity of vegetation in the woodland pastures and spreads species to new areas. This is supported by the lists of species found in different woodland pastures. Cattle destroy large grasses like Calamagrostis, which may avail growth of tree seedlings in the pastures. Grazing can also prepare the site for tree seedlings. On the other hand, prolonged grazing destroys tree seedlings and prevents regeneration.

The article includes a German summary.

  • Lampimäki, E-mail: tl@mm.unknown (email)
article id 4501, category Article
Ilmari Lehtinen. (1937). Eräitä näkökohtia rakennusten suunnittelussa ja korjaustöissä. Silva Fennica no. 39 article id 4501. https://doi.org/10.14214/sf.a13911
English title: Planning and renovation of buildings.
Original keywords: metsäopetus; metsänhoitajien jatkokurssit; rakentaminen; rakennusten korjaus; rakennusten ylläpito; puurakennus; puutalo
English keywords: forest education; professional development courses; maintenance of buildings; wooden house; renovation
Abstract | View details | Full text in PDF | Author Info

The issue 39 of Silva Fennica includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation describes building and renovation of wooden buildings, that were owned by the forest organizations.

  • Lehtinen, E-mail: il@mm.unknown (email)
article id 4496, category Article
E. A. Sopanen. (1937). Leimausehdotuksen laadinnasta. Silva Fennica no. 39 article id 4496. https://doi.org/10.14214/sf.a13906
English title: Planning of wood harvesting in Forest Service.
Original keywords: Metsähallitus; metsäopetus; metsänhoitajien jatkokurssit; leimikko; leimausehdotus; puukauppa
English keywords: Forest Service; forest education; professional development courses; wood sales; stand marked for harvesting
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation describes how to make a document required in Metsähallitus (Forest Service) when a stand is marked for harvesting.

  • Sopanen, E-mail: es@mm.unknown (email)
article id 4494, category Article
Eino Saari. (1937). Metsätaloudelliset tilastot. Silva Fennica no. 39 article id 4494. https://doi.org/10.14214/sf.a13904
English title: Forestry statistics.
Original keywords: tilastot; metsäopetus; metsänhoitajien jatkokurssit; valtion metsien inventointi; metsätilasto; hintatilasto; valtion metsien tilastot; metsävarat; hakkuutilastot
English keywords: National Forest Inventory; forest education; statistics; professional development courses; statistic of state forests; roundwood trade statistics
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation lists statistics available on forestry.

  • Saari, E-mail: es@mm.unknown (email)
article id 4480, category Article
Yrjö Ilvessalo. (1937). Käytännöllisistä metsänarvioimistavoista. Silva Fennica no. 39 article id 4480. https://doi.org/10.14214/sf.a13890
English title: Practical forest inventory methods.
Original keywords: metsänhoito; metsäopetus; metsänhoitajien jatkokurssit; metsänarvioiminen; puuvarat; metsien inventointi; linja-arviointi
English keywords: forest inventory; forest mensuration; forest education; professional development courses; wood resources; strip-survey
Abstract | View details | Full text in PDF | Author Info

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes different forest inventory methods.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
article id 4472, category Article
Pienpuukomitea. (1933). Pienpuukysymys. Silva Fennica no. 31 article id 4472. https://doi.org/10.14214/sf.a9044
English title: The small timber problem.
Original keywords: kuusi; Picea abies; metsänhoito; polttopuu; kuitupuu; pienpuu; puusokeri; puun kaasutus; puun kysyntä
English keywords: Norway spruce; fuel wood; pulp wood; wood sugar; wood gas; wood demand
Abstract | View details | Full text in PDF | Author Info

A Committee was appointed in 1931 to prepare a program to improve the trade of small timber and to develop Finnish fuels and their production. The low demand for small timber is caused by the reduced export of Egyptian balks, and decreased demand of fuel wood that have been replaced by the imported fuels, like coal. At the same time, the supply of small timber has grown significantly due to increased thinnings, and better transport facilities that have made timber more accessible. Also, decreasing demand of large timber has increased the supply of small timber. The demand of small timber concentrates on Norway spruce (Picea abies (L.) H. Karst.). The sales of small timber are crucial from the silvicultural point of view. Selection felling of large timber in the past has reduced the supply of logs and led to surplus of small timber.

The article discusses the uses of small timber and potential new fields, such as wood sugar as fodder or refining wood as fuel. The use of timber should be promoted especially in the domestic industry. The Committee suggests funding for an additional forestry teaching post in the University of Technology, for forest technology and forest economics research in the Forest Research Institute, for research in wood technics, and for follow-up of forest sugar and wood gas fields.

The PDF includes a summary in English.

  • Pienpuukomitea, E-mail: pk@mm.unknown (email)
article id 4470, category Article
Einar Maliniemi. (1933). Päivittäisistä paperipuiden valmistusmääristä eri vuoden aikoina Perä-Pohjolassa. Silva Fennica no. 29 article id 4470. https://doi.org/10.14214/sf.a9042
English title: Seasonal variations of pulpwood harvesting in the northernmost Finland.
Original keywords: kuitupuu; työtehotutkimus; hakkuu; Perä-Pohjola; puutavaranvalmistus; kausityö
English keywords: pulpwood; felling; time and motion study; labour productivity
Abstract | View details | Full text in PDF | Author Info

The fellings of small timber have been expanded from seasonal to full-year operation in many areas. A time and motion study was conducted on the felling of pulpwood in different times of the year in seven felling sites in the northernmost Finland. The work was payed per one pulpwood bolt. The output of a one-man teams was larger than 2-6-man teams. Teams of even numbers were more effective than teams of uneven numbers. One-man teams were more popular during summer. The output was largest during the summer. In the late summer the results decrease, because barking of trees becomes more difficult. Shortening of daylight hours begin to shorten the workdays in the autumn. In December, the average working days are about 6 hours. Snow and low temperatures make logging and barking more difficult during the winter. The output was lowest in January, despite that work days are 1 ½ hours longer than in December. It is concluded that pulpwood fellings should be avoided from December to March 15. If the fellings are necessary, the wage system should be changed more flexible than at present. The size of cutter’s lots should be adjusted so, that work periods are not too short. Sufficiently big lots save time spent on travelling between the sites and villages.

The PDF includes a summary in German.

  • Maliniemi, E-mail: em@mm.unknown (email)
article id 4469, category Article
Paperipuun-vientikomitea. (1933). Paperipuukysymys. Silva Fennica no. 28 article id 4469. https://doi.org/10.14214/sf.a9041
English title: The pulpwood question.
Original keywords: kuusi; vienti; kauppapolitiikka; komiteanmietinnöt; kuitupuu; paperiteollisuus; raakapuu
English keywords: forest management; Norway spruce; Picea abies; paper industry; wood consumption; wood export
Abstract | View details | Full text in PDF | Author Info

A Commission was appointed to examine the significance of pulpwood exports from the political-economic and social point of view. A survey was made of the development of woodworking industry in Finland. The article includes a detailed review on paper industry in Finland and abroad, pulpwood resources in Finland and outlook of the industry. The export of pulpwood was significant in 1925-1927, the most important country being Germany. The commission notes that It would be more profitable to refine the wood into more expensive products. It does, however, not see it necessary to restrict export of pulpwood. If restrictions are considered necessary, prohibition of export is a better way than export duties.

The best way to promote domestic paper industry is to increase the supply of Norway spruce (Picea abies (L.) H. Karst.). Measures are suggested to increase the productivity of the forests through forest improvement. The annual increment of spruce is calculated to cover the consumption in near future, provided the export of pulpwood does not amount to 600,000 m3, and the local demand of pulpwood does not exceed 7.8 million m3 annually. The Commission proposes that state ownership of forests is increased, forest management is intensified, and restrictions of forest industry to acquire forest land are removed.

It suggests also reliefs in taxation and import duties on fields related to transport, and equipment and raw materials needed by the paper industry.

The PDF includes a summary in English.

  • Paperipuun-vientikomitea, E-mail: pv@mm.unknown (email)
article id 4468, category Article
Martti Hertz. (1933). Metsän puutteesta sekä sen syistä ja torjumistoimenpiteistä Ruotsi-Suomessa. Silva Fennica no. 27 article id 4468. https://doi.org/10.14214/sf.a9040
English title: Forest devastation, its causes and prevention in Sweden-Finland.
Original keywords: metsänkäyttö; metsäpolitiikka; metsätuotteet; metsien häviäminen; metsiensuojelu; Ruotsi-Suomi
English keywords: forest policy; shifting cultivation; wood utilization; forest products; Ruotsi-Suomi
Abstract | View details | Full text in PDF | Author Info

The earliest local records of lack of timber in Finland are from the 1600th century when Finland belonged to Sweden. The causes vary from burning of tar and shifting cultivation to local factories using fuel wood. Best preserved were forests in Lapland and Kainuu in Northern Finland and those parts of Karelia where shifting cultivation was not practiced. Especially harmful was shifting cultivation, because it made it impossible to grow valuable timber. The state did not intervene in the use of forests until it itself began to need more wood. Shipbuilding was the first cause to limit the use of wood, especially need of mast trees of pine and oak. Also the use of timber by private sawmills began to raise general concern in the 16th century. They influenced the decrease of forests in the 1800th century, due to the limited wood procurement areas and selection felling of timber trees. The establishment of sawmills became regulated in 1700th century. Collective forest ownership by the farms was seen at the time one of the reasons to forest devastation. In 1654 the state of Sweden forbade the burning of mast or in timber forests. Mining industry needed much fuel wood, and shifting cultivation was forbidden near the mines in 1734. Regulations and instructions were also on given on use of wood, for instance, in building, in fences, leaf fodder, fuel wood and tar burning.

Despite of many efforts, the government of Sweden could not prevent devastation of forests in Finland. The many wars of the state hindered economic growth, the regulations were sporadic and often difficult to apply, there was little supervision, the understanding of forestry was poor, and the remote Finland was often neglected in Sweden.

The PDF includes a summary in German.
  • Hertz, E-mail: mh@mm.unknown (email)
article id 4455, category Article
O Tähtinen. (1930). Katsaus Jokioisten kartanon eli n.s. Jokiläänin metsätalouden vaiheisiin. Silva Fennica no. 14 article id 4455. https://doi.org/10.14214/sf.a8989
English title: A short account of the history of the forestry of the Jokioinen Estate.
Original keywords: metsänkäyttö; historia; kartano; kaskiviljely; polttopuu
English keywords: forest utilization; shifting cultivation; estate management; fuel wood; history
Abstract | View details | Full text in PDF | Author Info

The Jokioinen Estate was established in 1562 when king Erik XIV of Sweden granted a large area around Jokioinen in the southwest Finland to Klas Kristersson Horn. The estate had several landlords until it was acquired in 1872 by Jokkis Stock Company, and finally sold to the government in 1918. The forestry of the estate was influenced by complications concerning the ownership of the land. A part of the tenants of the estate had originally been independent and owned their farms, but some farms were so-called family-right-farms, which were inherited from father to son, but the farmer did not own the land. A third type of farmers were ordinary tenants, who were directly dependent on the landlord. Especially ambiguous was the family-right-farmers’ right to harvest timber from the forests. The Finnish government acquired the estate to solve the problems and gave the tenants right to buy their farms.

Until the 18th century most of the farmers in Jokioinen area practiced shifting cultivation. This method of farming influenced strongly the forests, and continued until the increased market price of timber made it unprofitable. The forests were also the source of fuel wood for both the farmers and the landlord. The estate had own saw-mill industry since the 18th century. In 1871 a trained forester was hired for the estate. When the government acquired the estate, it comprised 32,000 hectares of land. The state retained 7,000 hectares of the forests. They were managed by a trained forester and administrated under the Board of Agriculture.

The PDF includes a summary in English.

  • Tähtinen, E-mail: ot@mm.unknown (email)
article id 4453, category Article
Metsätieteellinen Tutkimuslaitos, Suomen Metsänhoitoyhdistys, Finnish Society of Forest Science. (1929). Näkökohtia Suomen metsätalouden tehostamiseksi. Silva Fennica no. 12 article id 4453. https://doi.org/10.14214/sf.a8986
English title: Improving the productivity of forestry in Finland.
Original keywords: metsätalous; puunkäyttö; metsäteollisuus
English keywords: forestry; forest industry; wood utilization
Abstract | View details | Full text in PDF | Author Info

The article is a joint study of the Forest Research Institute, the Forest Association and the Society of Forestry (now Finnish Society of Forest Science) on means to increase the productivity of forestry in Finland.

The study identifies five ways to improve the productivity of forestry in the country. First, the yield of forests should be increased by draining peatlands, reforestating understocked forests, changing tree species, if they are unsuitable for the site, increasing improvement fellings and enhancing regeneration in the cutting areas. Second, the utilization and trade of small-diameter timber should be developed. Third, export of wood should be promoted, while the use of wood as fuel instead of imported fuels should be increased. Fourth, the export of Finnish wood products should be secured, for instance, by reducing manufacturing costs and developing production methods in the industry. Fifth, both the elementary and higher education of forestry should be developed further.

The PDF includes a summary in English.

  • Metsätieteellinen Tutkimuslaitos, E-mail: mtl@mm.unknown (email)
  • Suomen Metsänhoitoyhdistys, E-mail: sm@mm.unknown
  • Finnish Society of Forest Science, E-mail: fs@mm.unknown
article id 4452, category Article
Eino Saari. (1929). Ehdotus puun käyttöä osottavan jatkuvan tilaston järjestämisestä Suomeen. Silva Fennica no. 11 article id 4452. https://doi.org/10.14214/sf.a8985
English title: A proposal to introduce permanent statistics of wood consumption in Finland.
Original keywords: hakkuumäärät; kaukokuljetus; puunkäyttö; tilastot
English keywords: fellings; consumption of wood; wood utilization; statistics
Abstract | View details | Full text in PDF | Author Info

The Forest Research Institute made an investigation on the wood consumption in Finland in 1927. This work brought up a need to organize continuous collection of statistics of wood consumption. Three kinds of existing statistics can be used: statistics of wood consumption, statistic of the fellings, and statistics of transport of wood.

Statistics on wood consumption, such as the fuel used by the industry and State railways are collected annually. The fellings in state forests are published annually, and also the wood manufacturing companies publish statistics of their forests. Furthermore, all fellings on sale, and use of own wood in wood manufacturing industry have to be reported to the forestry committees. These statistics are published annually. Railroads and floating are the main means of long distance transport of wood. These statistics give additional information of wood consumption. Further studies are needed to combine and standardize the statistics collected from different sources.

The PDF includes a summary in English.

  • Saari, E-mail: es@mm.unknown (email)

Category : Article

article id 7184, category Article
Bror-Anton Granvik. (1967). Havusahatavaran valmistus kenttäpyörösahalla : työtieteellinen tutkimus. Acta Forestalia Fennica vol. 84 no. 3 article id 7184. https://doi.org/10.14214/aff.7184
English title: The preparation of coniferous sawn goods using circular saws. A work study.
Original keywords: sahatavara; aikatutkimus; sahaus; kenttäpyörösahaus; havusahatavara
English keywords: time study; sawing; sawn goods; circular saw; softwood timber
Abstract | View details | Full text in PDF | Author Info

The objectives of the paper were to find out structure of the sawing time when using field circular saws, influence of the different factors on the sawing time and its structure, average sawing time per unit of raw material and sawn goods, and the fundamentals for the creation of an equitable system for the determination of the basis of payment in sawing work. The observations of the time study were made on both a single log and a work period basis. The material was collected using four saws of different brands.

The results showed that the season when the work was done, and top diameter of the logs to be sawn affected the constant times included in the total sawing time and the time used for sawing of center pieces. While the tree species did not affect the constant times, the grade of the logs of different tree species did have effect, especially in winter sawing. The factors affecting the different phases of the work are described in detail. The length of sawing time was longer in the winter than in the summer. The preparatory jobs in sawing required in average 82 cmin per log, and the time increased with increasing top diameter. The actual sawing is the most time-consuming part of the work, it took in average 132 cmin. 

The PDF includes a summary in English.

  • Granvik, E-mail: bg@mm.unknown (email)
article id 7174, category Article
Pentti Alho. (1967). Pohjois-Pohjanmaan rannikkokuntien maanjako-olot metsätalouden kannalta. Acta Forestalia Fennica vol. 82 no. 1 article id 7174. https://doi.org/10.14214/aff.7174
English title: Influences of partitioning of land in forestry in the municipalities of northern Ostrobothnia in Finland.
Original keywords: metsänhoito; kannattavuus; yksityismetsätalous; metsämaa; metsätilat; tilakoko; maanjako
English keywords: forest management; profitability; private forests; forest holdings; partitioning of land; size of woodlots
Abstract | View details | Full text in PDF | Author Info

Farm forestry in northern Ostrobothnia has met different kinds of obstacles that decrease its profitability, some national, some local. One of the later is partitioning of land. The purpose of this investigation was to survey the division of farm land in the coastal municipalities of northern Ostrobothnia in Finland, where the conditions are among the most unfavourable in the country in this respect. The material used in the investigation was collected in a previous study about the structure of the farms in the area. First part of the paper summarises the history of partitioning of land in Finland.

The results show that division of the woodlots of a farm are in the coastal municipalities of northern Ostrobothnia very disadvantageous for forestry. The average distance of a woodlot to the farmhouse is 8.3 km, but there is a great variation between the municipalities, and the distance varies from 30 to 1.9 km. The form of the lots, as the long ribbon-like woodlots in the municipality of Liminka, complicates often practical forestry. In addition, the number of separate woodlots is high, in average 9.2 per farm.

The great distance of the woodlots from the main farms hinders the use of forests and diminishes the financial result of forestry. Unfavourable form of the woodlots posts similar hindrances to harvesting of timber and forest management as the long distances and high number of separate plots. The problem is heightened by the abundance of peatlands in relation to productive forest lands in the area.

The PDF includes a summary in German.

  • Alho, E-mail: pa@mm.unknown (email)
article id 7142, category Article
Seppo Ervasti. (1964). Suomen sahateollisuuden kausivaihtelu. 2. Tutkimustulokset. Acta Forestalia Fennica vol. 76 no. 2 article id 7142. https://doi.org/10.14214/aff.7142
English title: Seasonal variation in the sawmill industry of Finland II. Investigation results.
Original keywords: sahateollisuus; puun kuljetus; kausivaihtelu; puunhankinta; puutavaran myynti
English keywords: wood harvesting; timber sales; sawmills; sawmill industry; timber transportation; wood procurement; seasonal variation; production of sawn wood; sales of sawn wood
Abstract | View details | Full text in PDF | Author Info

Seasonal variation in the sawmill industry of Finland was studied in an investigation based on questionnaires answered by a random sample of sawmills concerning the time period of 1958-1960. The method is described in detail in a separate article in Acta Forestalia Fennica issue 75 no. 1.

The seasonal variations in purchase of roundwood was largest in big sawmills, which purchase the main part of the timber as standing sales and buy most of the wood from the State Forest auctions at the end of September. Also, they can afford to reserve their material earlier than the smaller companies. The saw logs are mainly felled in the winter in Finland because the climatic conditions and availability of labour are best at that time. Small sawmills begin fellings a little earlier than the larger ones.

In long-transport of timber the proportion of floating decreased from 47% in 1958 to 38% in 1960. At the same time, proportion of truck transport increased from 48% to 55%. Small sawmills use almost exclusively land transport. They received almost three-fourths of their logs between January and May, because the sawing is concentrated in the first half of the year. Therefore, floating does not suit for their transport method. The larger the sawmill, the later is the seasonal peak of log deliveries. The output of the big sawmills is distributed more evenly thoughout the year. The smaller the sawmill, the quicker is the turnover of raw material and the smaller the sawlog inventories.

The seasonal variation in output is sharper at small sawmills where sawing is concentrated in the first half of the year. The seasonal peak of the early spring is due to the aim at getting the sawn wood to dry early enough for shipments in the summer. Air drying takes an average of 4 ½ months. Kiln drying is more common at the larger sawmills, and gives them more flexibility. Due to the large seasonal variation in operation, the capacity of the small mills is poorly utilized. Domestic sales of sawn wood levels up the seasonality of the deliveries. Export sales are concentrated at the end and turn of the year. Also, the seasonal peak of expenditure occurs in the winter, but that of income in the summer.

The PDF includes a summary in English.

  • Ervasti, E-mail: se@mm.unknown (email)
article id 7137, category Article
Yrjö Roitto. (1963). Ison-Saimaan yhteisuitto-ongelma. Acta Forestalia Fennica vol. 75 no. 3 article id 7137. https://doi.org/10.14214/aff.7137
English title: Problem of co-operative floating on the Iso-Saimaa in Eastern Finland.
Original keywords: uitto; puun kuljetus; vesikuljetus; Saimaa; Saimaan vesistöalue; Iso-Saimaa; yksityinen uitto; yhteisuitto
English keywords: Finland; floating; wood transportation; water transportation; private floating; co-operative floating; Lake Saimaa
Abstract | View details | Full text in PDF | Author Info

In Finland roundwood is floated either privately or co-operatively. In the later, a co-operative floating association is established to operate floating. The association is compulsory association of those enterprises who want to have wood floated along the floating routes of the area. It is favoured when the number of enterprises and the wood to be floated is large. In addition, costs are lower than in private floating.

Floating in Lake Saimaa area in Central Finland can be divided into Iso-Saimaa, where floating is private, and into Saimaa Water System, where floating is operated by a co-operative floating association. It has been suggested that adoption of co-operative floating in Iso-Saimaa would be to the common interest. This study aimed at finding out if co-operative floating influences the transport costs, and if co-operative floating increases competition of roundwood by forest industry companies.

According to the study, the costs of most enterprises would decrease. The total decrease in costs would amount to 65 million Finnish marks annually, about 20% less than the present costs. The change of organization would not alter the competitive relationship in buying roundwood. On the other hand, it would seem that co-operative floating would be less flexible than private floating. The management of a large organization, whose effective operation time would cover only a part of the year, would meet with some difficulties. Also, co-operative floating would reduce competition among enterprises.

The PDF includes a summary in English.

  • Roitto, E-mail: yr@mm.unknown (email)
article id 7127, category Article
Jouko Einola. (1961). Puutavaran hankintakustannusten ennakkolaskenta. Acta Forestalia Fennica vol. 73 no. 5 article id 7127. https://doi.org/10.14214/aff.7127
English title: Precalculation of logging costs.
Original keywords: hakkuu; hakkuukustannukset; kustannukset; kustannuslaskenta
English keywords: costs; wood sales; cost accounting
Abstract | View details | Full text in PDF | Author Info

The investigation studies the whole logging operation from the stump to the consumption. The main purpose is to obtain a maximum profit. Proceeds and costs have been studied from the view point of precalculation. First, basic costs theory concepts are introduced. Second, the role of precalculation is described and finally a survey of the practical calculation problems and its results are described.

The purpose of precalculation is to achieve the best possible total financial result for the whole enterprise. The aim is to maximize the difference between future proceeds and the costs. When an alternative calculation is prepared, as many promising alternatives as possible is sought, and the most advantageous of these are selected after a rough survey. Since contributory factors are changing, precalculation is a continuous operation.

Logging operations can be handled in various alternative ways, of which the most advantageous has to be chosen. If there is a large number of different courses of action, the target must be maximum contribution margin per time unit. With labour, too, the aim is to maximize the differentiation between proceeds and costs of a long-term point of view. A working plan of the alternative selected can be formed into a target calculation with the aid of budgets and standards. When purchasing timber, procurement plans can be drawn up and priced for each consignment, and then combined and scrutinized to give target calculations. If the factors affecting them change, the targets must be altered.

The PDF includes a summary in English.

  • Einola, E-mail: je@mm.unknown (email)
article id 7126, category Article
Viljo Holopainen. (1960). On the price elasticity of the supply of sawn wood for export. Acta Forestalia Fennica vol. 73 no. 4 article id 7126. https://doi.org/10.14214/aff.7126
Keywords: Finland; sawn timber; supply; export; demand; sawn wood; sawn goods
Abstract | View details | Full text in PDF | Author Info

The present investigation is concerned with the price elasticity of sawn wood, concentrating on the price elasticity of sawn wood supply for export. The supply of sawn wood for export is referred to the joint attitude to price changes of all producers participating in the market.

The study concludes that producers cannot in the short- and medium-term view use the price parameter to increase total utilization in the sawn wood market. Demand holds a primary position in price formation. The capacity reserve of the sawmills permits great variations in output at the mill level, and thus elasticity in the supply of sawn wood. High timber costs are typical for the industry. Supply of roundwood can easily be adapted even to large variations in demand. The price elasticity of roundwood supply is rather great.

The long process of sawn wood production and the resulting relatively long lead-time of deliveries result in a long adaptation time of supply. Expansion and contraction of sawn wood exports cause, via the effect of exports, on income similar fluctuations in the domestic sales of sawn wood. This weakens the price elasticity of exports in some degree.

The ‘instantaneous elasticity’ upwards of sawn wood supply might be great, but speculation with stocks at the different levels of production often makes it ‘incalculable’. The price elasticity of a medium-long and long period can be expected to be relatively great upwards. The downward elasticity of a period of medium length is probably small. The elasticity of a prolonged period may be influenced by the substitution of other materials for sawn wood.

The PDF includes a summary in Finnish.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 7125, category Article
L. Runeberg. (1960). European trade in raw wood during the 1950’s and prospects in the days of EEC and EFTA. Acta Forestalia Fennica vol. 73 no. 3 article id 7125. https://doi.org/10.14214/aff.7125
Keywords: Finland; Europe; roundwood; export; timber sales
Abstract | View details | Full text in PDF | Author Info

This paper concentrates on the roundwood commerce in Western Europe as seen from the point of view of Finland, considering the role of Eastern Europe. The first part analyses exports and imports both quantitatively and qualitatively, and the balance of the trade in the export countries. Second part covers the new market groups in Europe and the opportunities for a common market.

Arter the Second World War, a surprisingly large trade in roundwood reappeared in Europe. The European countries exported in average 11 million m3 of roundwood annually, of which 4.3 million m3 was pulpwood, and 2.8 million m3 pitprops. Finland leads exports during the 1950s with a yearly average of 4.2 million m3, followed by France and Sweden. Western Germany is the largest importing country with a negative balance of 2.8 million m3. It is concluded, from a theoretical point of view, that in Western Europe only Finland can maintain a large roundwood export. From a national point of view, however, it would be more favourable to expand the countries’ own refining industries.

On the whole, it seems as if the European roundwood trade should continue on a rather large scale during the 1960s, partly because the border trade can be expected to increase, with a freer trade, and partly because the European timber deficit needs filling from sources outside Europe. In addition, the pulp industries in the importing countries will compete more and more keenly with the exporting countries for pulpwood supplies.

The PDF includes a summary in Finnish.

  • Runeberg, E-mail: lr@mm.unknown (email)
article id 7122, category Article
Kullervo Kuusela. (1960). Pinotavaraleimikon taksatoriset tunnukset ja niiden vaikutus leimikkoarvioinnin tarkkuuteen. Acta Forestalia Fennica vol. 72 no. 5 article id 7122. https://doi.org/10.14214/aff.7122
English title: Mensurational characteristics of cordwood stock market for felling and their effect on the precision of stock estimation.
Original keywords: kuitupuu; metsänarviointi; kuutiomäärä; koeala; kuitupuuleimikko
English keywords: pulpwood; forest mensuration; methods; sample plots; pulpwood marked for felling
Abstract | View details | Full text in PDF | Author Info

The annual fellings and sales of pulpwood from the State Forests of Finland comprised 4.0–4.6 million m3 in 1955–1959. In order to improve the accuracy of the methods used in estimating the pulpwood stocks marked for felling, a pilot survey of 18 marked stocks was carried out in 1959. The stock area, average plot volume, variation of the plot volumes, size and shape of the plot and the distribution of the trees by diameter classes as factors affecting the precision have been studied in this paper.

The greater the mean volume of a plot the more homogenous is the structure of the marked stock. The same number of plots gives a better relative precision for the south Finnish marked stock than for the north Finnish ones, which are heterogenous and less valuable. Stocks smaller than 50 ha can often be estimated more advantageously by the strip method or visually than by the plot method. The proper size of plot in Southern Finland is 0.02–0.03 ha. In Northern Finland the plots should be larger due to the heterogenous stocks, about 0.05 ha. The shape can be either circular or rectangular. The former may be more practical and reliable in the field. The minimum number of sample trees is considered to be about 200 per 100 sample plots 0.03 ha in size.

The PDF includes a summary in English.

  • Kuusela, E-mail: kk@mm.unknown (email)
article id 7121, category Article
Viljo Holopainen. (1960). Marketing roundwood in Finland and the Scandinavian Countries. With special regard to marketing channels and trade customs. Acta Forestalia Fennica vol. 72 no. 4 article id 7121. https://doi.org/10.14214/aff.7121
Keywords: forest owners; roundwood; private forests; wood sales; timber sales; marketing of wood
Abstract | View details | Full text in PDF | Author Info

The present investigation set out to find out the structures of supply and demand, channels and methods of marketing, developments in marketing methods, trade customs, similarities and differences in marketing of the private forest owners and the State, local features of the market of domestic roundwood trade in Finland, and compares marketing of unprocessed wood between Finland and Scandinavian countries. The study is based on statistics of various sections of trade and from the State Boards of Forestry.

The channels of marketing from private forests in Finland and the Scandinavian countries are different. In Norway the wood is primarily marketed through the forest owners’ associations, in Finland direct individual selling is applied, while in Sweden both channels are common. In Norway and in Sweden the forest owners’ marketing organizations were probably formed mainly to protect the forest owners’ interest in price formation. The price is determined on the organizational level, while in Finland the price formation mechanism has retained a competitive nature. In Sweden the creation of demand for roundwood has been one reason for establishment of the associations, which have established new forest industry particularly in areas of low demand.

The institutions affect also the trade customs in Norway and Sweden. For instance, measuring of roundwood is performed in Scandinavia according to detailed public regulations and often carried out by the officials of special measuring boards. The Forms Committee has also since 1950 brought significant unification in the trade customs of Finland. Greatest differences in trade customs between the State and private forestry is observed in Finland.

The producer’s role in marketing has increased since 1930s, which is demonstrated by the increasing activity in marketing by the forest owners’ associations in Norway and Sweden. Also, the relative importance of sales with contract for delivery has been growing. A second line of development appears in the more detailed norms in trade customs.

The PDF includes a summary in Finnish.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 7119, category Article
Paavo J. Ollinmaa. (1960). Eräistä ojitetuilla soilla kasvavan puun fysikaalisista ominaisuuksista. Acta Forestalia Fennica vol. 72 no. 2 article id 7119. https://doi.org/10.14214/aff.7119
English title: Physical properties of wood growing on drained peatlands.
Original keywords: kuusi; ojitus; mänty; puun laatu; turvekankaat; rauduskoivu; hieskoivu; puuaine; lujuus
English keywords: Pinus sylvestris; Norway spruce; Betula pendula; Picea abies; Betula pubescens; drained peatlands; Scots pine; wood; mechanical strength
Abstract | View details | Full text in PDF | Author Info

The objective of the investigation was to determine the differences between faultless timber grown on a peatland before and after draining, in respect of compressive strength to the grain, volume weight, and shrinkage. In addition, the influence of the boundary zone between the close-ringed wood formed before draining and the wide-ringed wood produced after draining on strength of the timber was studied. The material consisted of 15 sample trees of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), white birch (Betula pubescens Ehrh.) and silver birch (B. Pendula Roth).

The volume weight of wood of the tree species in ascending order is; spruce, pine, white birch, silver birch. The volume weight of Scots pine seems to decrease from the butt end upwards, while no trend was revealed for spruce. In the coniferous trees, the wide-ringed wood formed subsequent to draining was slightly lighter than the close-ringed wood produced prior draining. No distinct trend was seen in the birch species. The volume weight of pine and spruce increased with decreasing width of the growth rings up to a certain limit, after which the conditions inverted.

The compressive strength of the different kinds of wood seems to increase from the butt end upwards, but after height of two meters it begins to decrease considerably. In birch, this point of inversion is in somewhat greater height. In spruce timber, the compressive strength parallel to the grain is lowest for wood which contains exclusively wide-ringed wood formed after draining. The boundary zone between the woods formed before and after draining is very distinguishable, but has no remarkable influence on the compressive strength parallel to the grain. Shrinkage of close-ringed wood is higher in all three principal directions than that of wide-ringed wood. This can be explained by the variations in volume weight and fibrillar orientation of the tracheid walls.

The PDF includes a summary in English.

  • Ollinmaa, E-mail: po@mm.unknown (email)
article id 7118, category Article
Paavo J. Ollinmaa. (1959). Reaktiopuututkimuksia. Acta Forestalia Fennica vol. 72 no. 1 article id 7118. https://doi.org/10.14214/aff.7118
English title: Study on reaction wood.
Original keywords: kuusi; mänty; havupuut; kataja; haapa; reaktiopuu; vetopuu; lujuus; leppä; kutistuminen; lehtipuut; lylypuu; ligniini
English keywords: Populus tremula; Pinus sylvestris; Norway spruce; Picea abies; Scots pine; compression wood; lignin; mechanical strength; Alnus incana; tension wood; shrinkage; Juniperus communis; raction wood; common juniper
Abstract | View details | Full text in PDF | Author Info

Compression wood of the tree species studied in this investigation, Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.) and common juniper (Juniperus communis L.), was found to be characterized in its cross section by the thick walls and rounded shape of its tracheids and the profuse occurence of spaces. Tension wood of aspen (Populus tremula L.) and alder (Alnus incana (L.) Moench) was found in microscopic examination to be characterized by the gelatinous appearance of the wood fibres, by its small cell cavities and by the thickness and buckling of the inner layer of the cecondary wall. Tracheids of the compression wood were found to have shorter length than normal on an average, while the tension wood fibres were found to be longer.

The microchemical studies suggest a higher than normal lignin content in compression wood and lower than normal lignin content in tension wood, as compared to normal wood. The reverse would be true for the cellulose contents. Volume weight of absolute dry reaction wood was distinctly higher than that of normal wood. The longitudinal shrinkage of reaction wood, particularly of compression wood, is several times that of normal wood. Transversal shrinkage of compression wood is much less than normal wood. Swelling tests revealed pushing effect of compression wood on elongation and pulling effect on tension wood on constraction. Volume shrinkage of compression wood is less than that of normal wood, in contrast to tension wood. The strength of compression wood in absolutely dry condition was nearly same as that of normal wood.

The PDF includes a summary in English.

  • Ollinmaa, E-mail: po@mm.unknown (email)
article id 7488, category Article
Viljo Holopainen. (1959). The concept of a roundwood price level and its determination in forestry. Acta Forestalia Fennica vol. 68 no. 6 article id 7488. https://doi.org/10.14214/aff.7488
Keywords: roundwood; roundwood prices; timber sales; price statistics; roundwood sales
Abstract | View details | Full text in PDF | Author Info

Roundwood statistics are essential in a country such as Finland, where the roundwood market costitutes one of the most important internal markets. Determining the price level of roundwood can, however, be problematic due to the difficulty of the empirical determination. The main difficulties are the many timber assortments, quality differcences within a timber assortment, large variation of local prices due to variations in demand and harvesting conditions and in sales methods. The article discusses these problems from the perspective of composing a roundwood statistics for different timber assortments that would allow local and temporal comparison of the prices. It seems impossible to compose price statistics that could eliminate totally the variation in the material, transport conditions and demand fluctuations caused by technical development. However, one can suffice to a compromise that would eliminate the major disturbances and take into account other factors that are not related with market when studying the price series. In addition, the paper discusses methods for calculation of price indices.

The PDF includes a summary in Finnish.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 7484, category Article
Seppo Ervasti. (1959). Suomen havusahatavaranmyynnin kausi- ja suhdannevaihteluista vuosina 1951-1958. Acta Forestalia Fennica vol. 68 no. 2 article id 7484. https://doi.org/10.14214/aff.7484
English title: On the seasonal and business cycle fluctuations of Finnish sawn softwood sales in 1951-1958.
Original keywords: vienti; sahatavara; suhdannevaihtelut; havusahatavara
English keywords: sawn timber; export; business cycles; sawn goods; sawn softwood; sawn sofwood sales
Abstract | View details | Full text in PDF | Author Info

The investigation examines export sales of Finnish sawn softwood sales in 1951-1958, concentrating on the volume of the sales. The material was collected from the archives of Finnish Sawmill Owner’s Association and the Finnish Sawmill Control Organization and the annual reports of the former. Correlation analysis was used in assessing the interdependence of the monthly sales volume and the price, and opening sales and the total sales volume of the year.

A slightly negative correlation was seen between the sale price and the monthly sales volume. Goods sold at under average prices are more abundant than goods sold at over average prices. Generally, with a rising price trend, the annual sales volume increased, but with falling prices the situation was reverse. The sales volume has been dependent on the business cycle development of prices. There was positive correlation between the opening sales and the total sales quantity for the year. The sales volume was at its maximum in the period between November and January, and at the minimum between March and September.

The time of the sales made to different countries differed little judged by quarterly statistics. It seems that the major shippers have generally concluded opening sales first. Northern Finnish shippers and the small shippers of Southern Finland have sold proportionately least during the last quarter. In general, the poorer the qualities in question the smaller on an average the proportion of opening sales but the greater the share of clearance sales.

The PDF includes a summary in English.

  • Ervasti, E-mail: se@mm.unknown (email)
article id 7480, category Article
Seppo Ervasti. (1958). Suomesta myydyn havusahatavaran hintasuhteiden muutokset vuosina 1932-38 ja 1951-56. Acta Forestalia Fennica vol. 67 no. 6 article id 7480. https://doi.org/10.14214/aff.7480
English title: Changes in the price ratios of sawn softwood sold by Finland in 1932-38 and 1951-56.
Original keywords: vienti; sahatavaran laatu; havusahatavara; hinnat; hintasuhteet
English keywords: Finland; sawn timber; prices; export; sawn goods; softwood; price indices; timber qualities
Abstract | View details | Full text in PDF | Author Info

The aim of the investigation was to estimate the changes in the price ratios of different tree species of sawn timber, timber sizes and qualities, the ratios of the prices obtained by different shippers and from different countries, and their changes, especially the trends and business cycles. The data can be utilized in the organization of sawing and the drawing up of the price scales. The price ratios were calculated by taking 100 as the basic quantity and calculating the values for the other quantities accordingly, the values are called price indices. The data is collected from the sales reports in the archives of the Finnish Sawmill Owners’ Association.

Comparing the ratios of the basic prices, the prices of unsorted pine goods by shipper B (the leading marks of Northern Finland), were considerably higher than the others. The North Finnish pine goods are of the best quality in Finland. The price differences between the other shippers were small. The prices of unsorted spruce goods differed very little with different shippers. In some years the basic prices obtained for pine from different countries showed considerable differences although, in the overall view, the differences were small.

In the leading marks of Northern Finland, the differences between pine and spruce prices was greater than the other price differences. The quality of pine logs in Northern Finland is extremely high. During the periods of prosperity, the price difference between pine and spruce was relatively smaller than during depression. With spruce goods, the relative price difference for the qualities is smaller than with pine goods. For the both species the relative price differences diminished with the increase in the basic price. In the broadest sizes of unsorted pine goods, the price difference of the inch class is much bigger than in the small sizes. This is true especially for boards. The relative price difference between boards and battens increased distinctly with the advance in the basic price. A similar, though not as clear change took place in the price ratio of board and 7” sizes. The price differences between battens and boards are much smaller for spruce than for pine. The trends of the price indices of the different sizes show from the middle of 1920s and as far as the 9” u/s pine sizes very gentle, and in regards of the corresponding spruce sizes, a fairly sharp rising tendency.

The PDF includes a summary in English.

  • Ervasti, E-mail: se@mm.unknown (email)
article id 7477, category Article
Yrjö Roitto. (1958). Raakapuun kaukokuljetus Saimaan vesistössä. Acta Forestalia Fennica vol. 67 no. 3 article id 7477. https://doi.org/10.14214/aff.7477
English title: Transportation of round timber in the Lake Saimaa water system.
Original keywords: uitto; puun kuljetus; vesikuljetus; kuljetuskustannukset; Saimaa; proomukuljetus; höyrylaiva; aluskanta; sisävesikuljetus
English keywords: barges; tugboats; roundwood; floating; water transport; Lake Saimaa; transport of wood; inland waterways; ships; steamships; transport costs; freight carrying vessels
Abstract | View details | Full text in PDF | Author Info

This paper aims at investigating which factors, in the point of view of the entrepreneur, define the choice of long-distance transport either as floating in bundles, steamship transport or barge transport in the waterway system of Lake Saimaa in 1950s. It defines the usage, kind of fleet, operation and costs of the abovesaid modes of transport. The investigation is mainly based on statistics of Enso-Gutzeit Oyj and the fuel office of the Finnish State Railways.

Location of the industrial enterprise sets the limits for use of the different modes of transport of roundwood. Previous decisions can influence the future choices, for instance, the capital the company has earler invested on the transportation system. Also, the type and amount of timber acquired by the company, transportation distance, time, and means of transport affect the choice of mode of transport. Those factors that direct decision-making, often lead the entrepreneur to stick to the chosen mode of transport.

Floating becomes the more inexpensive the larger the scale of operation is, and if the timber assortment is suitable for floating and water storage. For instance, dry wood is an asset for a wood export agency, and their sales have often time pressures, which rules floating out of their choices. Transportation in vessels has decreased to 4% of all roundwood haulage, but has its function as a supplementary way of transport.

The PDF includes a summary in German.

  • Roitto, E-mail: yr@mm.unknown (email)
article id 7474, category Article
Jouko Einola. (1957). Puutavaran hankinnan yhteiskustannukset. Acta Forestalia Fennica vol. 66 no. 4 article id 7474. https://doi.org/10.14214/aff.7474
English title: Joint costs of logging in Finland.
Original keywords: hakkuu; hakkuun kustannukset; kustannusanalyysi; puutavaran hankinta
English keywords: harvesting; logging; cost analysis; costs; wood harvesting
Abstract | View details | Full text in PDF | Author Info

The analysis of costs is the foundation for the efficient management of logging activities. However, there is little research on cost accounting of logging. This article is an overview on harvesting of timber and its cost accounting, concentrating on joint costs. Costs have to be divided on their structural elements and then regrouped according to different accounting needs to be investigated. This investigation bases the structural cost analysis on running booking of costs. Due to the variability of logging, the costs are divided in detail into categories. The costs of logging are classified by their origin into personnel cost, material costs, costs of services, compensation for use, unrequited costs, risks, depreciation and interest. Further, the costs are classified according to the subject and quality of performance, and by location.

The PDF includes a summary in English.

  • Einola, E-mail: je@mm.unknown (email)
article id 7471, category Article
Kalle Putkisto. (1956). Tutkimuksia pyörätraktoreiden käytöstä puutavaran metsäkuljetuksessa. Acta Forestalia Fennica vol. 66 no. 1 article id 7471. https://doi.org/10.14214/aff.7471
English title: Investigations of the use of wheel tractors for the forest transport of timber.
Original keywords: hakkuut; koneellistuminen; metsäkuljetus; maataloustraktori; hevoskuljetus; puutavaran kuljetus; traktori
English keywords: mechanization; timber harvesting; fellings; timber transport; horse haulage; forest transport of wood; tractor
Abstract | View details | Full text in PDF | Author Info

Forest transport of timber in Finland has been arranged as horse haulage during winter time using horses vacant from farm work. Tractors have now begun to replace horses in agriculture, which will lead to shortage of horses for timber harvesting in future. The aim of this investigation was to find a method of mechanized forest transport suitable for Finnish conditions. The method should be provided by an agricultural wheel tractor that is shared with agriculture. It should also be applicable to timber transport of relatively small forest holdings.

A method for time studies of tractor driven timber harvesting was developed. The competitivity of tractor transport of timber against the traditional method was studied in four pulpwood harvesting sites. The results suggest that if the tractor forest transport method in question is to be applied in practice, conditions should first be chosen which favour it most. A tractor forest transport method evolved on the basis of experiments presupposes certain conditions to be successful. These include snow for the construction of the packed-snow driveway, frost to harden the driveway, the location of strip roads in relatively easy topography, and of the main haulage road that is gently sloping in the haulage-loaded direction. The optimal transport distance for this method are about 3-10 km.

The PDF includes a summary in English.

  • Putkisto, E-mail: kp@mm.unknown (email)
article id 7463, category Article
Paavo J. Ollinmaa. (1955). Koivun vetopuun anatomisesta rakenteesta ja ominaisuuksista. Acta Forestalia Fennica vol. 64 no. 3 article id 7463. https://doi.org/10.14214/aff.7463
English title: On the anatomical structure and properties of the tension wood in birch.
Original keywords: koivu; rakenne; selluloosa; sahaus; rauduskoivu; hieskoivu; vetopuu; kemialliset ominaisuudet
English keywords: birch; Betula pendula; Betula pubescens; silver birch; downy birch; sawing; technical properties; structure; tension wood; pulp; chemical properties
Abstract | View details | Full text in PDF | Author Info

The investigation concerns with the strength of the eccentric growth accompanying formation of tension wood in silver birch  (Betula pendula Roth.) and downy birch (Betula pubescens Ehrh.), behaviour of wood in wood-working machines and its macroscopic characteristics, its microscopic and sub-microscopic structure, chemical composition, resistance against certain chemicals, physical properties, and the strength characteristics of wood.

The most detrimental properties of tension wood used in wood working industry are high longitudinal shrinkage, warping, twisting and checking. The wooliness of the cut is unwanted, for instance, in plywood and furniture. In pulp industry tension wood is better raw material than normal wood because it yields more and purer cellulose than normal wood. However, it has poorer strength properties.

The PDF includes a summary in English.

  • Ollinmaa, E-mail: po@mm.unknown (email)
article id 7462, category Article
Seppo Ervasti. (1955). Suomesta Pohjanmeren maihin vuosina 1920-1952 viety havusahatavara : koostumuksen muutokset. Acta Forestalia Fennica vol. 64 no. 2 article id 7462. https://doi.org/10.14214/aff.7462
English title: Export of sawn softwood from Finland to the North Sea Countries in 1920-1952.
Original keywords: vienti; sahatavara; Iso-Britannia; havusahatavara; sahatavaravienti; Alankomaat; Belgia; Ranska
English keywords: Finland; sawn timber; export; Great Britain; sawn goods; sawn softwood; the Netherlands; Belgium; France
Abstract | View details | Full text in PDF | Author Info

The objective of the investigation was to study the trends and fluctuations in the composition of sawn goods, changes due to business cycles, and casual fluctuations. The subject is confined to sawn softwood export to Great Britain, the Netherlands, Belgium and France (The North Sea countries) in 1920-1952. The data was based mainly on statistics of the Board of Customs, Series of Foreign Trade, Finnish Sawmill Owner’s Association and the Finnish Official Statistics.

The North Sea countries took 75-85% of the sawn softwood exported from Finland before World War II, and 50-70% of the quantity exported since the war. Sawn softwood export from Finland is almost exclusively long and small-dimension timber. The composition of the export from Finland to the North Sea countries was defined already during the 1900th century, and no big chances were observed even during the period of 1920-1952. The only definite trend was decrease in the proportion of u/s grade.

The PDF includes a summary in English.

  • Ervasti, E-mail: se@mm.unknown (email)
article id 7448, category Article
Viljo Holopainen. (1954). Suomen havusahatavaran viennin kausimaisuus. Acta Forestalia Fennica vol. 61 no. 36 article id 7448. https://doi.org/10.14214/aff.7448
English title: The seasonal fluctuations in the Finnish exports of sawn softwood.
Original keywords: vienti; kausivaihtelu; havusahatavara; kysyntä
English keywords: sawn timber; softwood lumber; export; demand; seasonal variations; sawn softwood; seasonal fluctuations
Abstract | View details | Full text in PDF | Author Info

The purpose of the investigation was to examine the seasonal pattern in Finnish export shipments and export sales of sawn softwood in 1927-1953. Statistics concerning shipments have been obtained from the Board of Customs, and material relating to sales has been provided by the Finnish Sawmill Owner’s Association (now Finnish Sawmills Association). On the basis of original monthly statistics, 13-month moving averages were computed. Finally, a seasonal index was calculated.

According to the results, the export shipments have a fairly apparent seasonal pattern with very low figures from January to April, a peak from June to August, and thereafter a gradual decline up to the end of the year. There are also considerable variations from year to year but in general the exports follow this rhythm. In contrast to export shipments the seasonal pattern of export sales is characterised by significant irregularity. Market developments and speculation play a far greater role than the seasonal factors. Indeed, a seasonal character in export sales can scarcely be discerned.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in English.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 7434, category Article
Jarl Lindfors. (1954). Sahatukkien kaukokuljetuksen eräitä piirteitä. Acta Forestalia Fennica vol. 61 no. 22 article id 7434. https://doi.org/10.14214/aff.7434
English title: Long-distance transport of saw logs in Finland.
Original keywords: puutavara; raakapuu; puunkuljetus; autokuljetus; vesikuljetus; hevoskuljetus; rautatiekuljetus
English keywords: roundwood; timber transportation; water transport; rail transport; truck transport; horse transport
Abstract | View details | Full text in PDF | Author Info

Central Association of Finnish Forest Industries decided in 1953 to begin collecting annual statistics of timber transportation of its members. The survey of members covers almost 97% of the timber transportations of the member companies, which have production over 1,000 cu ft. In all 79 companies answered the survey. Their total timber transportation was 166,4 million cu ft in 1952.

The long-distance transportation of saw logs by horse transport directly to the mill or other such location was 1,297 cu ft, by truck transport 42,644 cu ft, by rail transport 6,707 cu ft, and by water transport 115,789 cu ft. The average transportation distance was for horse transport 2.4 km, truck transport 27 km, rail transport 224 km and water transport 209 km.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.
The PDF includes a summary in German.

  • Lindfors, E-mail: jl@mm.unknown (email)
article id 7433, category Article
Yrjö Ilvessalo. (1954). Nationwide surveys of forest resources and wood utilization in Finland. Acta Forestalia Fennica vol. 61 no. 21 article id 7433. https://doi.org/10.14214/aff.7433
Keywords: forestry; National Forest Inventory; Finland; forest resources; wood utilization; forest balance; National Forest Survey; growth balance
Abstract | View details | Full text in PDF | Author Info

The first estimates on the forest resources of Finland were presented in the middle of the 1900th century. The first line survey was conducted in 1912 in Central Finland. In 1921-1923 a survey of the forests of the whole country was commenced. The method consisted in measurement of sample plots in conjunction with ocular estimation of all the stands within the range of the lines. The methods were further developed in the second National Forest Survey in 1936-1938, which payed special attention to the silvicultural condition of the forests, and the growth in the light of climatic variation. When 3.3 million ha of forests were ceded to the Soviet Union in the peace treaty of 1944, the results of the survey had to be recalculated. The next survey was conducted 1951-1953. In this survey, the recovery of stands on drained peatlands was studied. The results of the inventories show that forest resources of Finland had icreased since the 1936-1938 survey.

The first investigation of wood utilization in Finland was carried out in 1927, after the first National Forest Survey had provided information on the forest resources, and knowledge of the other side of the forest balance was desired. The most difficult part was to determine the domestic wood consumption of the rural population. This was accomplished by studying 1,337 sample farms. The second investigation was commenced in 1938, and third in 1954.

These two investigations have made it possible to determine the annual removal and annual growth, and by comparing these results, growth balance. A forest balance is an essential condition for judicious forestry.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
article id 7430, category Article
Veijo Heiskanen. (1954). Paperipuurankojen mittauksen tarkkuudesta Perä-Pohjolassa. Acta Forestalia Fennica vol. 61 no. 18 article id 7430. https://doi.org/10.14214/aff.7430
English title: On the accuracy of measurements of pulpwood boles in Northern Finland.
Original keywords: kuitupuu; tilavuus; paperipuu; mittaus; kuutioimistaulukot; tyvi-latvamittaus
English keywords: pulpwood; volume; wood measurement; volume tables; top measurement
Abstract | View details | Full text in PDF | Author Info

The study examines the accuracy of volume tables for top measurement of pulpwood boles, and that of top measurement in general in Northern Finland. In this method only top diameter and length of the boles are measured, and the volume is obtained from volume tables. The boles have previously been measured in the middle of the bole, but the method is very time consuming in practice.

The result indicates that the form of both Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) varies greatly. A pulpwood parcel, however, contains both rapidly and gently tapering logs, and the average form differences are much smaller. The difference between the real volume and the volume obtained from the volume tables is generally less than 12% and for more than third of the stock less than 4%.

Pine boles from private forests have been somewhat more and spruce boles less rapidly tapering than boles cut from state forests. The significance of the differences is not clear. Also, the boles in the northern part of the investigation area taper more sharply than those in the southern part.
It is concluded that the accuracy of the top measurement should be improved, but this is only theoretically possible by means of special tables and correction coefficients.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.
The PDF includes a summary in English.

  • Heiskanen, E-mail: vh@mm.unknown (email)
article id 7419, category Article
Paavo Aro. (1954). On the reasons for differences in the measurements of exported pulpwood. Acta Forestalia Fennica vol. 61 no. 7 article id 7419. https://doi.org/10.14214/aff.7419
Keywords: pulpwood; measurement; export; paper wood
Abstract | View details | Full text in PDF | Author Info

Exported wood is measured at the port in Finland by certified measurers. Wood is paid according to these measuring certificates. However, in many cases the buyer measures the wood again in the country of destination, and gets smaller amounts. This sometimes causes awkward situations.

To examine the phenomenon one lot of pulpwood was measured both in Finland and in the destination country Germany. Several differences were found for the amounts of wood, and the author discussed the possible reasons for these differences.

However, because of the possible scattering in the measurements, several reductions are always made to the measurements. Hence it was proved that the buyer got the amount of wood they paid for. It is clear that the current practices and tools used to measure the amount of wood do not allow for any more accurate measures.     

The PDF contains a summary in Finnish. 

  • Aro, E-mail: pa@mm.unknown (email)
article id 7417, category Article
N. Stolpe. (1954). Uittoa, sen organisatiota ja tulevaisuutta koskevia näkemyksiä. Acta Forestalia Fennica vol. 61 no. 5 article id 7417. https://doi.org/10.14214/aff.7417
English title: Observations on floating, its organizations and future in Finland.
Original keywords: uitto; puunkuljetus; autokuljetus; rautatiekuljetus
English keywords: floating; road transport; timber transportation; rail transport; transportation of rounwood; truck transport
Abstract | View details | Full text in PDF | Author Info

The costs of floating have increased by about 20-fold after the Second World War in Finland, which has raised concerns in the forest sector. At the same time, the costs of road transport have increased by 16% and costs of rail transport by 15%. Floating has been replaced mainly by road transport in transport of roundwood, especially near the factories. This development is likely to continue as new roads are built and the truck fleet develops.  

In spite of the changes in timber transportation, floating was still the most common way of transporting roundwood in 1952: 69% of saw logs, 53% of veneer timber, 42% of domestic pulp wood, 14% of exported pulp wood and mining timber and 14% of firewood was transported by a water route. There are several ways to improve the efficiency of floating and decrease its costs. This can be achieved in two ways. First, using modern technology, such as tugboats, bundlers and other equipment, and second, improving the operation and co-operation between different actors.  

The PDF includes a summary in German. 

  • Stolpe, E-mail: ns@mm.unknown (email)
article id 7415, category Article
W. E. Roitto. (1954). Eräitä näkökohtia Saimaan vesistöalueen puutavaran kaukokuljetuksen kehittymismahdollisuuksista. Acta Forestalia Fennica vol. 61 no. 3 article id 7415. https://doi.org/10.14214/aff.7415
English title: Development potential of transportation of roundwood in the river and lake system of Lake Saimaa in Finland.
Original keywords: uitto; puunkuljetus; uittoväylät; nippu-uitto; Saimaa; vesistö
English keywords: floating; floating channels; water transportation; timber transportation; Lake Saimaa; watersystem; transportation of wood
Abstract | View details | Full text in PDF | Author Info

About 17.5% of forest lands of Finland is situated around the river and lake system of Lake Saimaa. Furthermore, the growth of the forests  of the area correspond about 25% of the total growth of forests in Finland. The watersystem is one of the most important portages of roundwood in the country. It consists 11,000 km of floating channels, 2,000 km of which suit for floating in bundles. Annually 30-35 million cu ft of saw logs, 7 million cu ft of veneer timber and 2,5-3 million cu ft of pulp wood is floated in the area.

Even if the water system at present still suits well for floating, there are many opportunities for development, which would improve its competitiveness against other modes of transport. Several different sites where building of floating channels or improving the floatways are needed are described in the article.

The PDF includes a summary in German.

  • Roitto, E-mail: wr@mm.unknown (email)
article id 7414, category Article
Peitsa Mikola. (1954). Suomen maaseudun tulisijat. Acta Forestalia Fennica vol. 61 no. 2 article id 7414. https://doi.org/10.14214/aff.7414
English title: Rural fireplaces in Finland.
Original keywords: Suomi; puun käyttö; tulisijat; kiukaat
English keywords: firewood; Finland; fireplaces
Abstract | View details | Full text in PDF | Author Info

Wood consumption in Finland in 1938-1939 was studied by investigating the wood consumption of aprroximately 2,000 farms. One of the surveys connected to the investigation studied fireplaces and heating equipment in rural districts, and recorded the types of fireplaces in the farms.

The majority of the rural fireplaces are rather old-fashioned and the technically best equipment are rare. The fireplaces in Eastern and Northern Finland are often more primitive than in Western and Southern Finland.

In Western Finland, where hard bread is common, the baking oven is lit 30-50 times a year. In Eastern Finland, where soft bread is baked, the oven is lit about 200 times a year. The sauna i heated about 40 times a year in the west, and 80 times a year in the east.

The PDF includes a summary in English.

  • Mikola, E-mail: pm@mm.unknown (email)
article id 7413, category Article
V. Pöntynen. (1954). Tutkimuksia Suomen teollisuuden vuonna 1950 käyttämistä polttoaineista. Acta Forestalia Fennica vol. 61 no. 1 article id 7413. https://doi.org/10.14214/aff.7413
English title: Investigations into industrial fuel in Finland in 1950.
Original keywords: polttopuu; polttoaine; öljy; tuonti; tuontipolttoaineet; kysyntä; polttopuun hinta; kivihiili
English keywords: firewood; fuel; coal; coke; demand; import; price of fuel; domestic fuels
Abstract | View details | Full text in PDF | Author Info

The use of imported fuels has increased in Finland, which has resulted in a growing disregard of domestic fuels, primarily firewood, on fuel market. This has affected forest management and economy of forest owners as well as diminishing the working opportunities in the countryside by decreasing the demand of small-sized timber. This investigation studies the fuel problem in the industrial field by a survey sent to all industrial plants in the country.

The different fuels were converted to the calorific value of pine firewood measured in piled cubic meters (p-m3, cu.m.). In 1950 the industry utilized 14.1 million cu.m piled measure of imported and domestic fuels. Of this 47% was domestic fuels and 53% imported fuels. The share of coal was 40%, wood waste almost 30%, and firewood 18%. The relatively small proportion of firewood suggests that it could be possible to increase the industrial demand for firewood. However, it should be noted that industry uses fuel mainly for power production, where imported fuels are highly effective. Forest industry used 2/3 of all domestic fuel.

According to the report, waste wood was cheapest kind of fuel for industry. It was, however, often the plant’s own waste material. The cost of coal at the mill was 60% of the corresponding price of firewood. The location of the industry affects greatly the price relations between domestic and imported fuels. Coal is cheaper close to the harbours and the coastline of the country. The state has supported firewood transportation by lower freight rates for firewood.

The PDF includes a summary in English.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7406, category Article
Jaakko O. Murto. (1951). Mäntypuumme pihka voiteluöljyn raaka-aineena : puunkäyttöopillinen tutkimus. Acta Forestalia Fennica vol. 59 no. 2 article id 7406. https://doi.org/10.14214/aff.7406
English title: Finnish Scots pine resin as raw material for lubricating oil.
Original keywords: mänty; sota-aika; kannot; pihka; voiteluöljy; pihkaöljy; männynpihka; mäntyöljy; sulffaattiselluloosa
English keywords: Pinus sylvestris; Scots pine; resin; lubricating oil; war-time; tall oil; tar wood; sulphate pulp mill
Abstract | View details | Full text in PDF | Author Info

After the Second World War shortage of lubrication oil forced Finland to develop a substitute product that was produced of indigenous materials. This report is an overview of the history of the already terminated lubricating oil industry and it gives a detailed description of lubricating oil production.

The annual lubricating oil consumption in Finland was 15,000 tons before the war, but during the war it decreased to 7-8,000 tons. In 1943 Oy Tervaöljy Ab (Tar Oil Limited) was established with the state of Finland as the main shareholder. It was commissioned to plan and build tar and tar oil plants, and it also transmitted tar from stump wood pyrolyzing plants to oil factories. Two raw materials were used to produce tar oil: tar wood collected from Scots pine (Pinus sylvestris L.) stumps and tall oil, a by-product of sulphate pulp mills. A total of 9,000 tons of lubricating oil substitutes was produced in 1943-1947, 53% of this from sulphate pulp mill by-products and 47% from tar and shale oil.

The PDF includes a summary in English.

  • Murto, E-mail: jm@mm.unknown (email)
article id 7405, category Article
Viljo Holopainen. (1950). Eräiden Suomen kaupunkien halkojen hankinta-alueet : markkinatieteellinen tutkimus. Acta Forestalia Fennica vol. 59 no. 1 article id 7405. https://doi.org/10.14214/aff.7405
English title: The firewood supply areas of four Finnish towns.
Original keywords: polttopuu; Turku; polttopuun kysyntä; vesikuljetus; polttopuun kuljetus; rautatiekuljetus; Helsinki; Tampere; Vaasa
English keywords: firewood; supply; transportation; demand; water transportation; rail transport; shipping
Abstract | View details | Full text in PDF | Author Info

In the present investigation, the problems connected to demand of firewood are dealt with by studying the fuel markets of the three biggest towns in Finland – Helsinki, Turku and Tampere as well as those of Vaasa. The purpose of the investigation was to study the firewood supply areas in two time periods, in 1933-1939 and in 1945-1947, after the Second World War.

Railway and shipping were the most important ways for transporting firewood in 1933-1939. Towards the end of the period, road transport increased especially in Turku and in Vaasa. In 1945-47 almost 90% of the firewood transported to Helsinki, 60% to Tampere and Turku, and over 50% of the firewood transpors to Vaasa were carried by rail. One factor supporting rail transport was that the tariff policy of the State Railways gave preference to firewood transports.

The supply areas increased markedly from 1933-1939 to 1945-1947. Supply of firewood near the towns in the southern, southwestern and western parts of the country was small. Also, pulp industry began to use small-sized timber in 1930s, which increased competition of the wood. Coal and coke began to replace firewood in the 30s, but their use decreased during and after the war due to supply shortage.

The PDF includes a summary in English.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 7401, category Article
Veijo Heiskanen. (1950). Tutkimuksia pinopuutavaran proomuun lastauksesta. Acta Forestalia Fennica vol. 58 no. 1 article id 7401. https://doi.org/10.14214/aff.7401
English title: Investigations on loading piled wood into barges.
Original keywords: polttopuu; puunkuljetus; vesikuljetus; kuljetuskustannukset; proomukuljetus; proomu; lastaus; työtutkimus; työaika
English keywords: firewood; barges; time studies; transportation costs; water transport; transportation of timber; loading
Abstract | View details | Full text in PDF | Author Info

In Finland, transportation of wood by vessels has decreased, but is still an important mode of transport especially for firewood. In 1941-1947, nearly 25% of the firewood procured by the State Fuel Board was transported by vessels. This investigation concentrates on loading of wood into barges, since the share of wages of total expenses is greatest in this phase. The loading work amounts to nearly 40% of the total wages.

Two methods of loading barges are used in Finland: loading from the shore and truck loading. This study concentrates on the more common method, loading from the shore. A time study was conducted on the different stages of loading and piling wood into barges, most of which is done by hand. Most time-consuming part of the work is transporting the logs to the barge with a wheelbarrow, comprising over 40% of the working time. Time required for loading firewood is almost twice as much as loading pulp wood. Recommendations for loading places and organization of work are given in the article to improve the efficiency of the work.

The PDF includes a summary in English.

  • Heiskanen, E-mail: vh@mm.unknown (email)
article id 7374, category Article
Paavo Aro. (1942). Eräitä halkosahoilla suoritettujen sahauskokeiden tuloksia. Acta Forestalia Fennica vol. 50 no. 21 article id 7374. https://doi.org/10.14214/aff.7374
English title: Results of sawing experiments using wooden bow saw.
Original keywords: aikatutkimus; katkonta; sahanterät; halkosaha
English keywords: time study; cross-cutting; saw blades; wooden bow saw; bow saw
Abstract | View details | Full text in PDF | Author Info

Effectiveness of 18 different saw blades of wooden bow saw from four producers (Oy Suomen Sandvik Sahat, Epilä Oy, Ab Orsa Sågbladsfabrik Oy, Kone ja Terä Oy) was tested in 1937. The experiments were divided into test series according to type of maintenance of the blade and tree species (Scots pine, Norway spruce and birch) to be sawn. Each saw blade was sharpened into four different sharpening angles (54°, 60°, 64°, 70°). Four blades had markedly longer sawing times compared to the others. These blades had a special serration. In addition, two blades with sparse serration had slightly poorer results than the blades in general. When the tree species were compared, birch (Betula sp.) was slowest to saw followed by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.).

The PDF includes a summary in German.

  • Aro, E-mail: pa@mm.unknown (email)
article id 7371, category Article
Einari Wuoti. (1942). Kuusisahapuun teknillisen ja pinokuution välinen suhde sekä sen riippuvaisuus muotoluokasta. Acta Forestalia Fennica vol. 50 no. 18 article id 7371. https://doi.org/10.14214/aff.7371
English title: Relation between technical and piled cubic meter of Norway spruce saw logs and their relation to form class.
Original keywords: kuitupuu; tukkipuu; kuusitukki; puun hinta; kuusisahapuu; tekninen kuutiometri; pinokuutiometri; muotoluokka
English keywords: saw logs; pulpwood; form class; price of timber; wood price; technical cubic meter; piled measure; piled cubic meter
Abstract | View details | Full text in PDF | Author Info

Due to shortage of large logs, sawmill industry has been forced to buy also smaller logs, which also pulp industry uses as a raw material. Sawmills must be careful in the pricing of the logs, because profitability of sawing of timber depends on the size of the logs. These industries use different measures when they buy timber: pulp industry uses piled measure in meters, while saw logs are measured individually in cubic feet. The aim of the study was to develop sets of figures on technical cubic measure of a saw log and its relation to a piled cubic meter from the same log used as pulp wood. In addition, the effect of form class on the measures was studied.

The relation was assessed for trunks that had good, mediocre or unfavourable form class, which distinction is easy to make for a forest worker buying timber. The relations can be used by a buyer of saw logs or pulpwood who need to compare the prices or when the seller of the wood compares the offers.

The PDF includes a summary in German.

  • Wuoti, E-mail: ew@mm.unknown (email)
article id 7358, category Article
Arvo Ylinen. (1942). The effect of the amount of the summer wood on the elastic and tensile properties of coniferous trees. Acta Forestalia Fennica vol. 50 no. 5 article id 7358. https://doi.org/10.14214/aff.7358
Keywords: coniferous trees; tensile properties; elasticity; summer wood; autumn wood; linear function
Abstract | View details | Full text in PDF | Author Info

The dependence of elastic and tensile properties of coniferous trees on the share of summer wood can be presented as linear functions, if the soft wood is considered as a statically indefinite structure. By eliminating the share of summer wood by a certain function presented in the article, the elastic and tensile properties are the linear functions of density.

The functions are proved right by conducting strength tests on pine. Practical implications of the derived functions in rating the quality of wood are also presented.

The PDF contains a summary in Finnish. 

  • Ylinen, E-mail: ay@mm.unknown (email)
article id 7346, category Article
Th. Wegelius. (1939). The presence and properties of knots in finnish spruce : investigations concerning the origin and characteristics of branch and knot wood in finnish spruce with particular consideration given to the raw material needs of the paper industry. Acta Forestalia Fennica vol. 48 no. 1 article id 7346. https://doi.org/10.14214/aff.7346
Keywords: Picea abies; pulpwood; quality of wood
Abstract | View details | Full text in PDF | Author Info

The most important characteristics for the quality of round timber is knottiness. Knots decrease the strength of the wood in sawn goods. Knots in pulpwood obstruct the production process of ground pulp and lower the quality. A qualitative classification of saw logs has been suggested, and the abundance of knots could also be used to determine the quality of pulpwood. In this study, visual observations on the preparation of pulpwood in pulp mill were made to observe the quality of the wood. Samples of the wood was collected, and they were divided in five quality classes. To study the influence of age, forest site type and stand on knots, 140 sample trees of Norway spruce (Picea abies (L.) H. Karst.) were analyzed. The article includes detailed analysis of the abundance and position of knots in the stems of spruce, anatomical structure of the knots, microscopic structure of the fibers, and mechanical properties of the branch and knot wood.

  • Wegelius, E-mail: tw@mm.unknown (email)
article id 7317, category Article
Erkki Laitakari. (1935). Tutkimuksia metsikön ja kasvupaikan vaikutuksesta kuusen rungon kelpoisuuteen. Acta Forestalia Fennica vol. 41 no. 4 article id 7317. https://doi.org/10.14214/aff.7317
English title: Studies on the influence of stand and forest site type on the quality of Norway spruce stem.
Original keywords: kuusi; Picea abies; laatupuu; oksikkuus; rungon laatu
English keywords: branchiness; knottiness; quality timber; quality of wood
Abstract | View details | Full text in PDF | Author Info

Healthy, straight, more or less free from branches and slowly tapering stems are good raw material for woodworking industry. The aim of the study was to investigate, from the stand point of forest management, the influence of stand and forest site type on the technical quality of the stems. Sample plots were measured in Norway spruce (Picea abies (L.) H. Karst.) stands in Eastern Finland. Norway spruce growing in a stand with closed crowns developed thin branches and self-pruned, if the stand was dense in the early stages. The decisive time for the stand is, therefore, when it is at seedling stage and young stand. The stems are more branchy if the stand has been planted. The adequate planting density is discussed based on earlier studies. The sufficient density seems to be achieved when the spacing is at maximum two meters. When the stems are branchless up to four meters, thinning of spruce stand does not affect knottiness or stem form. A sparsely stocked, knotty young stand does not produce good-quality timber even if the stand is later dense. Selective thinning from above can be used to improve the quality of the wood.

The PDF includes a summary in German.

  • Laitakari, E-mail: el@mm.unknown (email)
article id 7309, category Article
I. Lassila. (1934). Kestävyys puun laadun tunnuksena. Acta Forestalia Fennica vol. 40 no. 32 article id 7309. https://doi.org/10.14214/aff.7309
English title: Durability as indication of wood quality.
Original keywords: puun laatu; puuaine; lujuus; kestävyys
English keywords: wood; strength; timber; durability
Abstract | View details | Full text in PDF | Author Info

The article reviews the change in how the most sufficient wood material was chosen for different uses. The craftsmen used different characteristics to determine the quality of wood, for instance, tree species, location in the stem, whether it was sapwood or heartwood etc. Scientifically, the quality of the wood has been described by, for instance, specific gravity, bending strength and compressive strength. Durability would, however, be better attribute than strength to describe the quality of wood, because circumstances, like humidity and temperature can change where the wood is used. The article discusses further the development of durability indexes.

The PDF includes a summary in German.

  • Lassila, E-mail: il@mm.unknown (email)
article id 7291, category Article
Paul Wallden. (1934). Tutkimuksia koivupuun anatoomisen rakenteen ja teknillisten ominaisuuksien keskinäisestä riippuvuudesta solumittauksien perusteella. Acta Forestalia Fennica vol. 40 no. 14 article id 7291. https://doi.org/10.14214/aff.7291
English title: Studies on relationship between anatomical structure and technical properties of birch wood.
Original keywords: koivu; puu; taivutuslujuus; Betula pubescens; putkilo
English keywords: wood; downy birch; bending strength; tracheid; libriform cell
Abstract | View details | Full text in PDF | Author Info

Birch wood is used widely in wooden structures where mechanical strength is needed. The aim of the research was to study the influence of the relative share of mechanically weak tracheids, and length of the wood fibers on specific gravity and bending strength of downy birch (Betula pubescens Ehrh.) wood. According to the results, the strength of wood is strongly dependent on the relative share of tracheids, and length of the libriform cells. The strength of the wood increases when the share of tracheids decreases and the length of libriform cells increases. The specific gravity can be used as an indication of the strength of wood, especially if it is possible to analyze the structure of the wood.

The PDF includes a summary in German.

  • Wallden, E-mail: pw@mm.unknown (email)
article id 7286, category Article
Matti Jalava. (1934). Havaintoja puun aseman vaikutuksesta puun ominaisuuksiin. Acta Forestalia Fennica vol. 40 no. 9 article id 7286. https://doi.org/10.14214/aff.7286
English title: Influence of the position of a tree in the stand upon the properties of the wood.
Original keywords: mänty; puun laatu; harvennushakkuu; puuaine; lujuus; latvus; kesäpuu; puun mekaaniset ominaisuudet
English keywords: Pinus sylvestris; thinning; Scots pine; crown; properties of wood; strength of wood; summerwood
Abstract | View details | Full text in PDF | Author Info

The growth of a tree is influenced by inherited properties and external circumstances, including climate, soil, the position of the tree in the stand, and the position of the wood in the stem. The tree species have optimum climate and optimum conditions. The aim of this study was to determine if the summerwood content of the wood of Scots pine (Pinus sylvestris L.) is dependent on the rate of growth of the tree. Comparing the position of the sample trees in the stand, it seems that the position of the tree and the size of its crown influences strongly the quality of the wood. In a dense stand the summerwood content was higher in the trees that had small crowns. Thinning of the stand decreased the difference in summerwood content of the trees.

The PDF includes a summary in English.

  • Jalava, E-mail: mj@mm.unknown (email)
article id 7277, category Article
Einari Wuoti. (1933). Kuusipaperipuun kutistumisesta ja kutistumisen osuudesta pinon painumiseen. Acta Forestalia Fennica vol. 39 no. 6 article id 7277. https://doi.org/10.14214/aff.7277
English title: Studies on shrinkage of Norway spruce pulpwood and its effect on sinking of the stacks.
Original keywords: kuitupuu; puukauppa; pino; pinomitta
English keywords: pulpwood; stacked wood; stack; piled wood; measuring of stacked wood
Abstract | View details | Full text in PDF | Author Info

When the volume of the pulpwood was determined from the dimensions of the stack, the practice was to add an agreed percentage to the height of the stack which took account of the sinking of the stack as the wood dried. The stack was piled to the agreed added height, or the percentage was compensated when the stack was delivered to the buyer. The aim of the study was to determine a more accurate percentage to be used in the pulpwood sales.

The dimensions of a stack of Norway spruce (Picea abies (L.) H. Karst) pulpwood and the diameter of each log was measured during the drying. The 223 cm high pile sank by 0.8% to 221 cm, and the stacked cubic meter decreased from 4.46 m3 to 4.42 m3. However, the shrinkage of a solid cubic meter of the wood was 2.8%, markedly more than the sinking of the stack.

The PDF includes a summary in German.

  • Wuoti, E-mail: ew@mm.unknown (email)
article id 7268, category Article
V. Pöntynen. (1932). Höyryalusten polttopuun kulutus. Acta Forestalia Fennica vol. 38 no. 2 article id 7268. https://doi.org/10.14214/aff.7268
Original keywords: polttopuu; polttoaine; höyryalus
English keywords: fuelwood; fuel; coal; steamboat; steamship
Abstract | View details | Full text in PDF | Author Info

A questionnaire was sent to the steamship owners to investigate the annual fuelwood consumption of the steamships in Finland in 1927‒1929. Most of the steamships used split spillet as fuel, and the share of coal and waste wood remained low. The fuelwood consumption of cargo ships, passenger ships and tugboats was calculated for different kinds of steamships, and by the engine power of the ships and by the fuelwood type. The annual fuelwood consumption of cargo ships was 22,768‒27,390 m3, passenger ships 24,738­‒33,616 m3 and tugboats 76,764‒113,791 m3 in 1927‒1929.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7267, category Article
V. Pöntynen. (1932). Jalostamattoman puutavaran vienti Suomesta vuosina 1911-1931. Acta Forestalia Fennica vol. 38 no. 1 article id 7267. https://doi.org/10.14214/aff.7267
English title: Export of roundwood from Finland in 1911‒1931.
Original keywords: vienti; raakapuu; sahatukki; puun vienti; parru
English keywords: roundwood; export; saw timber; rafters; spars; spillet
Abstract | View details | Full text in PDF | Author Info

The export of roundwood from Finland was studied based on the official statistics of foreign trade. The volumes were converted to solid volumes under bark. Roundwood (logs and masts) or raw timber trade consisted mainly of saw logs. The main tree species was Scots pine (Pinus sylvestrs L.) and Norway spruce (Picea abies (L.) H. Karst.). The annual volumes varied from 29,200 m3 in the war year 1918 to 657,200 m3 in 1924. Before the World War I the roundwood was exported mainly to Sweden and Russia, after the war the trade to Russia ceased. Also split spillet was a significant export item before the war. The export peaked in 1916 to 3 million m3, but decreased after the war to 30,000‒40,000 m3. The most important export item in the group of hewn timber has been Egyptian rafters, with annual export of 15,000‒284,600 m3 with the exception of the time of war. The export of spars exported to other countries than Egypt was highest before the war with 125,000 m3. The export of sleepers varied strongly, peaking in 1922. The total export of roundwood varied from 131,000 m3 in 1918 to 4.3 million m3 in 1927. Roundwood has mainly been exported to the European countries. Before the war, the main trading partners were United Kingdom and Russia. After the war the share of United Kingdom was nearly half of the volume, and Russia was replaced with Sweden.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7266, category Article
Eino Saari. (1931). Tutkimuksia Suomen puuvanuketeollisuuden raaka-ainekustannuksista. Acta Forestalia Fennica vol. 37 no. 4 article id 7266. https://doi.org/10.14214/aff.7266
English title: Investigations into the costs of raw material in the Finnish pulp industry.
Original keywords: kuitupuu; selluteollisuus; puun hinta; mekaaninen massa; puuhioke; kemiallinen massa
English keywords: pulpwood; pulp industry; mechanical pulp; chemical pulp; wood prices
Abstract | View details | Full text in PDF | Author Info

The article is a review on the wood procurement and cost of pulpwood in the Finnish mechanical and chemical pulp industry in 1922‒1926, based on statistics collected from the members of the Central Association of the Finnish Woodworking Industries (now Finnish Forest Industries), and the series Statistics of Industry and Foreign Trade. Wood trade is carried out by three types of sale: standing sales where the buyer of the wood takes care of fellings and transport (55% of the volume), contracts for the delivery of pulpwood (45% of the volume), and fellings in the own forests of the industry. Norway spruce (Picea abies (L.) H. Karst.) was the most important tree species, and was used almost exclusively especially in the mechanical pulp mills. According to the study, the demand of pulpwood increased markedly during the period. The stumpage prices did, however, not increase accordingly until in 1926. It is assumed that also the supply of wood was high after the World War I.

The PDF includes a summary in English.

  • Saari, E-mail: es@mm.unknown (email)
article id 7265, category Article
V. Pöntynen. (1931). Suomen puunjalostusteollisuuden raaka-aineen käyttö vuosina 1911-29. Acta Forestalia Fennica vol. 37 no. 3 article id 7265. https://doi.org/10.14214/aff.7265
English title: Wood consumption of wood manufacturing industry in Finland in 1911‒1929.
Original keywords: metsäteollisuus; sahateollisuus; selluteollisuus; puun käyttö; puu raaka-aine; vaneriteollisuus; puuhiomo
English keywords: forest industry; wood consumption; pulp industry; sawmilling industry; plywood industry; mechanical pulp
Abstract | View details | Full text in PDF | Author Info

The main source of data was the official industrial statistics in 1911‒1929. The data was complemented with information from other sources, and the figures converted to solid volumes under bark. The wood consumption of wood manufacturing industry in the period varied strongly, being lowest in 1918 (2.2 million m3) and highest in 1927 (18.1 million m3). The wood consumption dropped during the World War I.

The wood manufacturing industry in Finland concentrated on sawmilling industry which has used annually 70‒80% of the wood consumed in the whole wood manufacturing industry. Other sectors of industry using wood were plywood industry, wood-wool industry, spool factories, match industry, mechanical pulpwood industry and pulp industry.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7259, category Article
I. Lassila. (1929). Metsätyypin vaikutuksesta puun painoon. Acta Forestalia Fennica vol. 36 no. 1 article id 7259. https://doi.org/10.14214/aff.7259
English title: The influence of forest site type on the weight of wood.
Original keywords: mänty; Pinus sylvestris; metsätyyppi; puuaineen paino
English keywords: Scots pine; wood; basic density; weight of wood
Abstract | View details | Full text in PDF | Author Info

Earlier research has presented contradictory results of the influence of forest site type on the weight of wood. In this study, dominant trees of Scots pine (Pinus sylvestris L.) was chosen as sample trees on four forest site types: Calluna, Vaccinium, Myrtillus and Oxalis site types. The trees were felled in autumn, when the water content of the wood is low. Weight of the test samples was measured weigh before and after drying. Undried wood, both sapwood and heartwood, is heavier in Myrtillus type than in Vaccinium type. The weight of the air-dried heartwood did not differ between the two forest site types. Air-dried- sapwood was heaviest in Myrtillus site type. Air-dried heartwood was heaviest in Vaccinium site type, and lightest in Oxalis type. Owen-dried sapwood was heaviest in Calluna site type, where the tree growth is slow, but weight differences were small in owen-dried heartwood. It can be claimed that forest type affects wood quality.

The PDF includes a summary in English.

  • Lassila, E-mail: il@mm.unknown (email)
article id 7203, category Article
I. Lassila. (1926). Puun mekaanillis-teknillisten ominaisuuksien tutkimuksesta, sen tuloksista ja tehtävistä. Acta Forestalia Fennica vol. 31 no. 4 article id 7203. https://doi.org/10.14214/aff.7203
English title: Research on mechanic technical properties of wood.
Original keywords: puuaine; puun rakenne; lujuus; puun mekaaniset ominaisuudet
English keywords: mechanical strength; technical properties of wood
Abstract | View details | Full text in PDF | Author Info

The article includes a detailed review on the technical properties of wood. The weight, water content, strength and conductivity of the wood, and the factors affecting them are discussed. The mechanical and technical properties of wood are influenced, for instance, by tree species, age and part of the tree, geographical situation, site and growth conditions of the stand, anatomical structure of the wood, and temperature. The author summarizes the topics where further research should be addressed. For instance, the forest site types developed in Finland could be utilized in studies of the mechanic technical properties of wood.

The PDF includes a summary in English.

  • Lassila, E-mail: il@mm.unknown (email)
article id 7095, category Article
Eino Saari. (1923). Sahapuun kantohinta ja menekki Suomen valtionmetsissä vv. 1913-1922. Acta Forestalia Fennica vol. 27 no. 2 article id 7095. https://doi.org/10.14214/aff.7095
English title: The stumpage prices and demand of saw timber in state forests of Finland in 1913-1922.
Original keywords: sahateollisuus; kantohinta; puun hinta; havutukki
English keywords: roundwood; stumpage price; sawmill industry; saw timber; timber price
Abstract | View details | Full text in PDF | Author Info

The survey focuses on the stumpage prices of standing sales, where the buyer of the wood takes care of felling and transport of the timber. The study concentrates further on conifer sawn timber. The prices of the sawn timber rose continuously from 1891 to 1910. After 1913 the stumpage price fluctuations reflected the changes in the market. The article includes a detailed description on the changes of the saw timber in 1913-1922 and the factors affecting the prices. The prices are shown for different parts of the Finland. The first world war affects the prices and demand on saw timber in 1917-1918. In Northern Finland the prices of sawn timber increased slower than in Southern Finland. In general, the unfavorable factors have had stronger impact on the stumpage prices than the favorable.

The PDF includes a summary in German.

  • Saari, E-mail: es@mm.unknown (email)
article id 7091, category Article
August Renvall. (1923). The degree of radial shrinkage of pine stem wood from Lapland according to behavior of increment cores. Acta Forestalia Fennica vol. 26 no. 3 article id 7091. https://doi.org/10.14214/aff.7091
Keywords: pine; stem wood; shrinkage; increment core
Abstract | View details | Full text in PDF | Author Info

Shrinking of timber when drying is a phenomenon that causes variation in measuring of timber in timber trade and on using the timber for construction or other purposes.   

The data for the article consists of 332 increment core samples from pine trees different ages, sizes and growth rate. There were collected in years 1910-1912 in Finnish Lapland, regions Utsjoki and Inari. The increment cores were collected on the height of 1.3 meters in south-north direction straight crosswise through the whole tree. The samples are 6mm thick. The diameter of the samples was measured immediately after making the sample and after several years’ storage in room temperatures. Also the age of the trees was determined.

The results are presented in tables. The degree of shrinkage varies heavily between the samples but stays anyhow between 1.5 and 3.9%. The mean degree of shrinkage for 314 samples was 2.9%. The results seem to indicate that the bigger the shrinkage the denser the annual growth ring system of the tree, meaning the slower the growth has been.  The older and of diameter bigger trees shrink less than younger and smaller trees. 

  • Renvall, E-mail: ar@mm.unknown (email)
article id 7039, category Article
Olli Heikinheimo. (1920). Pohjois-Suomen kuusimetsien esiintyminen, laajuus ja puuvarastot. Acta Forestalia Fennica vol. 15 no. 1 article id 7039. https://doi.org/10.14214/aff.7039
English title: The distribution and volume of Norway spruce forests in Northern Finland.
Original keywords: Pohjois-Suomi; kuusi; Picea abies; puuvarat; levinneisyys; valtion maat
English keywords: state forests; wood volume; Norway spruce area
Abstract | View details | Full text in PDF | Author Info

Norway spruce (Picea abies (L.) H. Karst.) forests in Northern Finland are situated mainly in the state lands. The survey is based on silvicultural surveys made in the northernmost districts of the state forests. The quality of private lands of the area was deduced based on the adjacent state lands and specific observations. A map was drawn on the distribution of productive Norway spruce forest in the study area.

The continuous Norway spruce forest areas covered 1,112,000 hectares, of which 866,000 hectares were on the state lands. Especially in the northern parts of the area also more fragmented spruce forest could be found (130,000 hectares in the state lands). The estimated total volume of the wood in the forests in the state and private lands was 57.78 million m3 in the continuous spruce forest area. The spruce forests were often situated on hill and fell areas relatively high above the sea level. In the areas north of the 66th parallel, almost half of the forests were above 300 meters above the sea level. Because spruce forests of the state lands were concentrated near watershed areas, the wood harvesting was more expensive, and reduced the value of the state forests. The spruce forests grow usually on fresh mineral soil sites. However, towards north the species was found on drier sites. The stands were mostly pure spruce stands or mixed birch-spruce stands. The older age groups were the most common, but young stands were rare.

  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 7010, category Article
O. J. Lakari. (1915). Studies on seed years and age-class distribution of pine forests on heathlands of northern Finland. Acta Forestalia Fennica vol. 5 no. 1 article id 7010. https://doi.org/10.14214/aff.7010
Keywords: seed years; age class distribution; age gradation distribution; heathy woodland; heathland
Abstract | View details | Full text in PDF | Author Info

The data has been collected from northern Finland between about 64th and 68th north latitudes, excluding the polar tree line areas. The sample plots have been selected to represents greatest variation of the habitats in altitude, rainfall and other site factors. The selected trees were cut, their age, height, and diameter at various heights examined and possible signs of forest fires noticed. The age of the trees was examined also with microscope. The age class distribution of the sample plots was studied. The determination of historical seed years was based on age class distribution of the sample plots.  

Grouping of the trees into different age classes was too weak a method to make any conclusions about the periodicity or even less about the frequency of the seed years.  There were also noticeable differences in determining the age of the trees between macroscopic and microscopic age examination. There are also differences in the amount of seedlings between different forest types.

The growth of pines in northern Finland is very slow particularly in the young ages but the growth increases after they reach 1,3 meters, which may take up to 30 years. The development of the forest has been similar through last centuries
  • Lakari, E-mail: ol@mm.unknown (email)
article id 7535, category Article
Olli Heikinheimo. (1915). Observations about manufacturing and storage of firewood. Acta Forestalia Fennica vol. 4 no. 3 article id 7535. https://doi.org/10.14214/aff.7535
Keywords: percentage of moisture; fire wood; experiment
Abstract | View details | Full text in PDF | Author Info

The moisture content of the wood has negative impact on transport, storage and use of wood, particularly this can be noticed on firewood. The moister the wood the harder is the transportation and storing. The high percentage of moisture also reduces the heating power of fire wood.

Drying of the wood of different tree species was studied at the forestry institute Tuomarniemi with following experiment setup: pines, spruces, birches, aspens and alders were logged and cut into one-meter split billets. Then they were dices according Huber’s formula. The wood was stacked in three similar ricks (stacks), varying the direction of the cut surface. The various tree species were distributed evenly to every rick. The split billets were weighted straight after manufacturing and after every month.

The wood dries fastest during spring and summer months. The direction of the cut surface of split billets in the rick makes no big differences in drying. The coniferous wood dries up to lower moisture content than broadleaved   woods.
  • Heikinheimo, E-mail: oh@mm.unknown (email)
article id 7511, category Article
Jukka Tyrväinen. (1995). Wood and fiber properties of Norway spruce and its suitability for thermomechanical pulping. Acta Forestalia Fennica no. 249 article id 7511. https://doi.org/10.14214/aff.7511
Keywords: Picea abies; wood properties; pulpwood; fiber properties; thermomechanical pulping; pulp properties
Abstract | View details | Full text in PDF | Author Info

In the first part of the study, the selected wood and fiber properties were investigated in terms of their occurrence and variation in wood, as well as their relevance for thermomechanical pulping process and related end-products. It was concluded that the most important factors were the fiber dimensions, juvenile wood content, and in some cases, the content of heartwood being associated with extremely dry wood with low permeability in spruce. The following pulpwood assortments of which pulping potential was assumed to vary were formed: wood from regeneration cuttings, first-thinnings wood, and sawmill chips.

In the experimental part of the study, the average wood and fibre characteristics and their variation were determined for the raw material groups. Subsequently, each assortment – equalling about 1,500 m3 roundwood – was pulped separately for 24 h period. The properties of obtained newsgrade thermomechanical pulps were then determined.

Thermomechanical pulping (TMP) from sawmill chips had the highest proportion of long fibres, smallest proportion of fines, and had generally the coarsest and longest fibers. TMP from first-thinned wood was the opposite, whereas that from regeneration cuttings fell in between these two. High proportion of dry heartwood in wood originating from regeneration cuttings produced a slightly elevated shives content. However, no differences were found in pulp specific energy consumption. The obtained pulp tear index was clearly the best in TMP made from sawmill chips and poorest in pulp from first-thinned wood, which had generally inferior strength properties. No big differences in any of the strength properties were found between pulp from sawmill residual wood and regeneration cuttings. Pulp optical properties were superior in TMP from first-thinnings. No noticeable differences were found in sheet density, bulk, air permeance or roughness between the three pulps.

The most important wood quality factors were the fibre length, fibre cross-sectional dimensions and percentage juvenile wood. Differences found in the quality of TMP assortments suggest that they could be segregated and pulped separately to obtain specific product characteristics and to minimize unnecessary variation in the raw material and pulp quality.

  • Tyrväinen, E-mail: jt@mm.unknown (email)
article id 7510, category Article
Arto Rummukainen, Heikki Alanne, Esko Mikkonen. (1995). Wood procurement in the pressure of change. Acta Forestalia Fennica no. 248 article id 7510. https://doi.org/10.14214/aff.7510
Keywords: productivity; cost; timber harvesting; wood procurement; future scenarios
Abstract | View details | Full text in PDF | Author Info

Linear optimization model was used to calculate seven wood procurement scenarios for years 1990, 2000 and 2010. Productivity and cost functions for seven cutting, five terrain transport, three long distance transport and various work supervision and scaling methods were calculated from available work study reports. All methods are based on Nordic cut to length conditions. Finland was divided in three parts for description on harvesting conditions. Twenty imaginary wood processing points and their wood procurement areas were created for these areas. The procurement systems, which consists of the harvesting conditions and work productivity function, were described as a simulation model. In the LP-model the wood procurement system has to fulfil the volume and wood assortment requirements of processing points by minimizing the procurement cost. The model consists of 862 variables and 560 restrictions.

Results show that it is economical to increase the mechanical work in harvesting. Cost increment alternatives effect only little on profitability of manual work. The areas of later thinnings and seed tree- and shelterwood cuttings increase on cost of first thinnings. In mechanized work one method, 10-tonne one grip harvester and forwarder, is gaining advantage among other methods. Working hours of forwarder are decreasing opposite to the harverster. There is only little need to increase the number of harvesters and trucks or their drivers from today’s level. Quite large fluctuations in level of procurement and cost can be handled by constant number of machines, by alternating the number of season workers and by driving machines in two shifts. It is possible, if some environmental problems of large-scale summer time harvesting can be solved.

  • Rummukainen, E-mail: ar@mm.unknown (email)
  • Alanne, E-mail: ha@mm.unknown
  • Mikkonen, E-mail: em@mm.unknown
article id 7684, category Article
Pekka Mäkinen. (1993). Puutavaran kuljetusyritysten menestymisen strategiat. Acta Forestalia Fennica no. 238 article id 7684. https://doi.org/10.14214/aff.7684
English title: Strategies used by timber truck companies to ensure business success.
Original keywords: kannattavuus; puutavaran kuljetus; strategiset ryhmät; puutavaran autokuljetus; kuljetusyritykset; kilpailustrategia; liikkuvuuden esteet
English keywords: competitive strategy; profitability; wood transport; Timber truck transportation; mobility barriers; strategic group
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to determine how timber truck transport business succeeds in the competition within its sector, and the effect it has on profitability structure of the sector. Furthermore, strategic groups were looked at in depth, as well as the competitive strategies of the most successful companies and groups of companies. The theoretical competitive strategy was operationalized.

A total of 53 timber truck transport entrepreneurs were interviewed. The average age of the entrepreneurs was 51 years. Of the businesses, 35% were partnership companies, 6% open companies, and 59% self-employed. The business owned an average 1.5 trucks, and at the time of interviewing their average age was four years. Nearly nine out of ten entrepreneurs had no schooling for the line of business, and four out of five had no short-term training. The attitude of the timber truckers toward their activities was more like that of self-employed persons than that of entrepreneurs. A total of 61.5% of them reporter that they carried on entrepreneurship simply to assure themselves a job.

The operational profitability of the sector has been good in the years 1984 to 1990, and the business profitability fairly good. The median equity ratio in the sector has remained at about 20% and the ratio of debts to turnover about 40%. The sector has been more profitable than forest machine contracting primarily due to the barriers to entry into the sector.

Cluster analysis, using Ward’s method, was used for seeking out strategic groups. The lengths of the customer relationships proved a significant barrier to mobility. The most successful business used the competitive strategy of cost weighted focussing. This was done through optimization of the capacity utilization rate and through choice of correct customers. The strategic position for successful business was judged to be good in the future. Success in the future will require above all activeness and innovation ability.

The PDF includes a summary in English.

  • Mäkinen, E-mail: pm@mm.unknown (email)
article id 7682, category Article
Juha Nurmi. (1993). Heating values of the above ground biomass of small-sized trees. Acta Forestalia Fennica no. 236 article id 7682. https://doi.org/10.14214/aff.7682
Keywords: heating value; small-sized trees; whole-tree biomass; wood chemistry
Abstract | View details | Full text in PDF | Author Info

The heating values of wood, inner and outer bark, and foliage components of seven small-size tree species (Pinus sylvestris L., Picea abies (L.) H. Karst., Betula pubescens Erhr., B. pendula Roth, Alnus incana (L.) Moench, A. glutinosa (L.) Gaertn., Populus tremula L.) were studied. Significant differences were found between species within each component. However, the differences between species for weighted stem, crown and whole-tree biomass are very small. The weighted heating value of the crown mass is slightly higher than that of the stem in all species. The heating value of stem, crown and whole-tree material was found to increase with increasing latitude.

The effective heating value of wood correlated best with the lignin content, inner bark with carbohydrate, and outer bark with carbohydrates and the extractives soluble in alkalic solvents. It is suggested that the determination of the heating value might be used as an indicator of the cellulose content of coniferous wood.

The PDF includes a summary in Finnish.

  • Nurmi, E-mail: jn@mm.unknown (email)
article id 7681, category Article
Eero Nikinmaa. (1992). Analyses of the growth of Scots pine: matching structure with function. Acta Forestalia Fennica no. 235 article id 7681. https://doi.org/10.14214/aff.7681
Keywords: Pinus sylvestris; Scots pine; pipe model; nutrients; heartwood; growth models; carbon budget; structure; partitioning of growth; growht
Abstract | View details | Full text in PDF | Author Info

A theoretical framework to analyse the growth of Scots pine (Pinus sylvestris L.) is presented. Material exchange processes and internal processes that transport, transform and consume materials are identified as the components of growth. Hierarchical system is lined out. Momentary uptake of material at a single exchange site depends on the environmental condition next to the exchange site, the internal state of the biochemical system of the plant and the structure of the plant. The internal state depends on the exchange flows over period of time and the structural growth depends on the internal state. The response of these processes to the fluxes is controlled by the genetic composition of the plant.

The theoretical framework is formulated into a mathematical model. A concept of balanced internal state was applied to describe the poorly known internal processes. Internal substrate concentrations were assumed to remain constant but tissue-specific. A linear relationship between the quantity of foliage and wood cross-sectional area was assumed to describe balanced formation of structure. The exchange processes were thus described as a function of external conditions. The stand level interactions were derived from shading and effects of root density on nutrient uptake.

The approach was tested at different levels of hierarchy. Field measurements indicated that the hypothesis of the linear relationship described well the regularities between foliage and sapwood of a tree within a stand when measured at functionally corresponding height. There was considerable variation in the observed regularities in the range of geographic occurrence of Scots pine. Model simulations gave a realistic description of stand development in Southern Finland. The same model was also able to describe growth differences in Lapland after considering the effect of growing season length in the parameter values. Simulations to South Russia indicate stronger deviation from the observed patterns.

The simulations suggest interesting features of stand development. They indicate strong variability in the distribution of carbohydrates between tree parts during stand development. Internal circulation of nutrients and the reuse of the same transport structure by various needle generations had a strong influence on the simulation results.

The PDF includes a summary in Finnish.

  • Nikinmaa, E-mail: en@mm.unknown (email)
article id 7680, category Article
Jouko Hämäläinen, Markku Kuula. (1992). An integrated planning model for a farm with an adjoining woodlot. Acta Forestalia Fennica no. 234 article id 7680. https://doi.org/10.14214/aff.7680
Keywords: farms; integrated planning; woodlots; economic planning
Abstract | View details | Full text in PDF | Author Info

The study deals with medium-term economic planning for a multi-branched farm enterprise on which agriculture and forestry plus associated livelihoods are practiced. A personal enterprise consisting of the earning economy sphere of an individual person or family is found to provide a suitable point of departure and framework for farm enterprise planning. In this case, the consumer economy cash withdrawals of the entrepreneur and members of his family are linked to the planning model. In a combined planning model of this type serving the management of the agricultural entrepreneur’s entire economy, the problems of both the real process (chiefly pertaining to agriculture and forestry) and the financial process are solved simultaneously and optimally with regard to the goal function, taking into consideration the model’s production factor, financing, taxation and other such constraints. The model also takes into account the possibility of investing money in financial targets (e.g. governments bonds and stocks).

The study consists of constructing a multi-periodic, combined planning model in the form required by linear optimization. The model is applied to the economic planning of a farm and its adjoining woodlot located in south-western Finland. In order to simplify the presentation of the matter, the case calculation is made to apply to a planning period only two years; the time span in the formulae used in the model is actually ten years. For the same reason, the number of treatment alternatives for the stands in the woodlot may appear to be unrealistically small.

Within the planning period the model does not require the use of the calculation rate of interest typical of partial models; instead, it itself provides the solution to where to invest and what the financing costs will be. An essential feature of the model is that the plan for the entire farm is not compiled by adapting to one another the plans made separately for farming, forestry etc., and financing; instead, the entire real process and financial process plan are obtained as the solution for the model.

The PDF includes a summary in Finnish.

  • Hämäläinen, E-mail: jh@mm.unknown (email)
  • Kuula, E-mail: mk@mm.unknown
article id 7673, category Article
Jimin Tan. (1992). Planning a forest road network by a spatial data handling-network routing system. Acta Forestalia Fennica no. 227 article id 7673. https://doi.org/10.14214/aff.7673
Keywords: spatial analysis; road network; wood transport; forest roads; locating
Abstract | View details | Full text in PDF | Author Info

The basic objective in planning a forest road network is to minimize the total cost of terrain transportation, road transportation, road construction and maintenance by controlling the road location, road network density and road quality, besides environmental and ecological considerations. Studies on the optimization of forest road network have encountered difficulties in taking into account the spatial diversity of forest terrain and stands. The spatial data handling-network routing system developed in this study proves to be useful in assisting forest managers to carry out the planning of forest road networks by covering the spatial and economic analysis.

The PDF includes a summary in Finnish.

  • Tan, E-mail: jt@mm.unknown (email)
article id 7665, category Article
Seppo Vehkamäki. (1990). Woodlot price formation in the early 1980s. Acta Forestalia Fennica no. 218 article id 7665. https://doi.org/10.14214/aff.7665
Keywords: forest ownership; forest holdings; woodlot sales; woodlot purchasing price; woodlot transaction price
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to explain both theoretically and empirically the formation of the unit price of a woodlot in the early 1980’s in Finland. The structure of the market in which woodlot transactions take place is described by analysing the volume of markets, the heterogeneity of the woodlots, institutional regulation of woodlot ownership and information concerning the market. The decision-making processes of both woodlot seller and buyer are examined using a theoretical model. Using a woodlot transaction sample for 1983 and 1984 woodlot unit price is explained empirically.

The PDF includes a summary in Finnish.

  • Vehkamäki, E-mail: sv@mm.unknown (email)
article id 7656, category Article
Kari Leinonen, Matti Leikola, Antti Peltonen, Pentti Räsä­nen. (1989). Kuusen luontainen uudistaminen Pirkka-­Hämeen metsälautakunnassa. Acta Forestalia Fennica no. 209 article id 7656. https://doi.org/10.14214/aff.7656
English title: Natural regeneration of Norway spruce in Pirkka-Häme Forestry Board District, Southern Finland.
Original keywords: kuusi; luontainen uudistaminen; taimettuminen; suojuspuumenetelmä
English keywords: Picea abies; natural regeneration; shelterwood method; restocking
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.

The standing volume prior to the shelterwood cutting was on average 236 m3/ha (ranging from 80 to 428 m3/ha) and after the cutting 120 m3/ha (39–220 m3/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.

The PDF includes a summary in English.

  • Leinonen, E-mail: kl@mm.unknown (email)
  • Leikola, E-mail: ml@mm.unknown
  • Peltonen, E-mail: ap@mm.unknown
  • Räsä­nen, E-mail: pr@mm.unknown
article id 7640, category Article
Seppo Vehkamäki. (1986). The economic basis of forest policy: a study on the goals and means of forest policy. Acta Forestalia Fennica no. 194 article id 7640. https://doi.org/10.14214/aff.7640
Keywords: forest policy; forest ownership; forest taxation; wood supply
Abstract | View details | Full text in PDF | Author Info

The goal-setting in forest policy and the means available for achieving the desired goal of forest policy are examined in this study. Examination of the goal is done using a macromodel of a closed economy. In the model GNP is assumed to be linearly dependent on the supply of raw wood. The model is used to derive the marginal conditions of the optimum equilibrium forestry with respect to the growing stock and the silviculture. The effect on the forest owners’ behaviour of the following means are examined: the taxation of ”pure income” from forestry, the taxation of income from selling raw wood, unit sales taxation and ad valorem sales taxation of forestry and corresponding sales subsidies, the support of silvicultural investments and the channelling of income from wood sales into silvicultural investments. The marginal conditions have been defined according to the maximum principle. An empirical study concerning the raw wood market in the case of softwood logs, and silvicultural investments in the case of young stand tending, has been carried out on the basis of the theoretical examination.

The PDF includes a summary in Finnish.

  • Vehkamäki, E-mail: sv@mm.unknown (email)
article id 7637, category Article
Jouko Silvola, Jukka Välijoki, Heikki Aaltonen. (1985). Effect of draining and fertilization on soil respiration at three ameliorated peatland sites. Acta Forestalia Fennica no. 191 article id 7637. https://doi.org/10.14214/aff.7637
Keywords: wood ash; soil respiration; drained peatlands; nitrogen fertilization; groundwater table; PK fertilization
Abstract | View details | Full text in PDF | Author Info

Soil respiration readings are reported for three ameliorated peatland sites of different types, covering a period of four years, during which the sites were drained and treated with various fertilizers. Respiration is shown to increase exponentially with temperature, varying mostly in the range 100–500 mg CO2 m-2 h-1. The changes in soil respiration followed those in surface temperature with a time-lag of approximately 3–3.5 hours. At one site, where the groundwater table dropped by about 0.5 m after ditching, soil respiration increased 2.5-fold within a few weeks, whereas at the other two sites both the fall in the groundwater table and the resultant changes in soil respiration were small.

The fertilizers tested were slow-dissolving PK, fast-dissolving PK, wood ash, slow-dissolving PK + urea, slow-dissolving PK + Nitroform (urea formaldehyde) and slow-dissolving PK + urea + a micro-element mixture. Application of fast-dissolving PK + urea led to a rapid increase in soil respiration at the site poorest in nutrients, and slow-dissolving PK to a slow increase in respiration. The greatest, steady increase of all was achieved by treatment with ash. At the sites with a higher natural nutrient content the application of fertilizers usually led to a decline in soil respiration lasting 1–2 years, after which the initial level was normally regained. Treatment with micro-elements caused an initial fall in soil respiration values in all three biotopes, followed by a pronounced increase.

The PDF includes a summary in Finnish.

  • Silvola, E-mail: js@mm.unknown (email)
  • Välijoki, E-mail: jv@mm.unknown
  • Aaltonen, E-mail: ha@mm.unknown
article id 7630, category Article
Esko Mikkonen. (1983). Eräiden matemaattisen ohjelmoinnin menetelmien käyttö puun korjuun ja kuljetuksen sekä tehdaskäsittelyn menetelmävalinnan apuvälineenä. Acta Forestalia Fennica no. 183 article id 7630. https://doi.org/10.14214/aff.7630
English title: The usefulness of some techniques of the mathematical programming as a tool for the choice of timber harvesting system.
Original keywords: matemaattinen ohjelmointi; standardi lineaarinen optimointi; parametrinen optimointi; tavoiteoptimointi; sekalukuoptimointi; kokonaislukuoptimointi; puunhankinnan suunnittelu
English keywords: mixed integer programming; integer programming; goal programming; wood procurement; mathematical programming; standard linear programming; parametric programming
Abstract | View details | Full text in PDF | Author Info

The applicability of five mathematical programming methods, namely standard linear programming, parametric programming, goal programming, mixed integer programming and integer programming is discussed as a planning tool for the choice of wood procurement method.

Theoretically, the goal programming approach seems to be the best routine for mathematical handling of problems related to wood procurement. The parametric approach must include enough large post-optimality analysis routine. If the effect of the variables expressed with different measures is to be studied, interpretation of the economic information given by the approach becomes a problem. The other drawback is that the approach does not allow determination of the hierarchy of the goals objectively as they depend on the subjective preferences of the decision maker.

From the practical point of view, standard linear programming is the best method if the objective function can be formulated in economic terms, for instance. If there are several goals to be attained or satisfied the best method is goal programming.

According to the sub-studies, every method under consideration can be used as a solution routine for the minimization of wood procurement costs. In cost minimization the best methods are goal programming and standard linear programming. The best method for harvesting system evaluation purposes is parametric because it allows varied cost calculations within a certain cost range. The best method for harvesting equipment investment planning is mixed integer programming with binary decision variables.

The more complicated and restricted the problem environment is, the better the mathematical programming approach will be, also in harvesting related problems.

The PDF includes a summary in English.

  • Mikkonen, E-mail: em@mm.unknown (email)
article id 7628, category Article
Eljas Pohtila, Tapani Pohjola. (1983). Lehvästöruiskutuksen ajoitus kasvukauden aikana. Acta Forestalia Fennica no. 181 article id 7628. https://doi.org/10.14214/aff.7628
English title: The timing of foliage spraying during the growing season.
Original keywords: mänty; herbisidit; taimikonhoito; lehdistöruiskutus; havupuutaimikot
English keywords: Pinus sylvestris; Scots pine; herbicides; seedling stands; MCPA; spraying of foliage; clearing of seedling stands; Roundup; DM; softwood seedling stand; hardwood sprouts
Abstract | View details | Full text in PDF | Author Info

An attempt was made in the study to determine the annual periods available for foliage spraying when cleaning Scots pine (Pinus sylvestris L.) dominated seedling stands. The study was made in nine experimental fields which were established in different parts of Finland. The spraying was applied throughout the growing season by DM, MCPA and Roundup. The results were inventoried one year after the treatments.

The results showed that there were big differences both in the destruction of hardwood sprouts and in the survival of pine seedlings due to the time period of the spraying. Threshold points were observed in the range of effect of DM and MCPA. By means of these it is possible to time the spraying treatments in such a way that there remains only slight damage to pine, but hardwood sprouts are destroyed totally. The results varied with Roundup so much, among other things due to rain, that such threshold points could not be determined. This preparation both had a milder effect on the hardwood seedlings and caused slighter damage to pine than the other preparations.

In Sodankylä in Northern Finland, the pines attained a good resistance to arboricides when the efficient temperature sum of the growing season was 550, but in Punkaharju in Central Finland only when it was 850. The seed provenance of the seedlings had an effect on the resistance. The threshold temperature sums of resistance in pine were on the average 70–74% from the long-term average number of degree days at the origin of the seed. The effect on the hardwood trees grew weaker as the long-term average was filled. Resistance of pine followed with a specific lag the lignification of the shoot and the ceasing of the growth of the needles.

The PDF includes a summary in English.

  • Pohtila, E-mail: ep@mm.unknown (email)
  • Pohjola, E-mail: tp@mm.unknown
article id 7587, category Article
Yrjö Roitto. (1976). The economic transport unit size in roundwood towing on Lake Iso-Saimaa [in eastern Finland]. Acta Forestalia Fennica no. 153 article id 7587. https://doi.org/10.14214/aff.7587
Keywords: Finland; roundwood; floating; floating in bundles; timber transportation; water transport; Lake Saimaa; bundle raft; towing enterprise; unit cost
Abstract | View details | Full text in PDF | Author Info

The transport unit in roundwood towing on Lake Iso-Saimaa in Central Finland comprises a tug and a raft of bundled wood with a towline between them. There are several factors influencing the economic size of the transport unit in roundwood towing. These are changing with the enterprises and along with general developments. In this paper these factors or factor groups are seen from the point of view of the enterprise. The main question is to determine the most economic combination of tug and raft size.

From the point of view of the towing enterprises the unit costs of transport are the most decisive factor. Both the size of the raft as well as the power of the tug influence strongly the unit costs. As a long-term goal a raft of about 35,000 m3 and a tug of 550 kW or more is considered to be advisable. The width of channels and sounds then allow a free passage for rafts being 36–40 m wide.

The PDF includes a summary in Finnish and in French.

  • Roitto, E-mail: yr@mm.unknown (email)
article id 7578, category Article
Yrjö Ilvessalo, Mikko Ilvessalo. (1975). Suomen metsätyypit metsiköiden luontaisen kehitys- ja puuntuottokyvyn valossa. Acta Forestalia Fennica no. 144 article id 7578. https://doi.org/10.14214/aff.7578
English title: The forest types of Finland in the light of natural development and yield capacity of forest stands.
Original keywords: metsätyypit; puuntuotantokyky; alueellinen jakautuminen
English keywords: wood production; forest types; regional differences; yield capacity
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to describe the forest types of Finnish mineral forest lands as a uniform whole in the light of stand development and wood production.

The study shows that it has been possible to work out uniform age-based development series for different stand characteristics for forest types on mineral forest lands in Finland. There is generally a clear difference in the development series of various stand characteristics and their average values between different forest types. The exceptions in a few places have been explained as depending on certain factors. The differences between adjacent forest types in order of their quality are of varying magnitude, thus differing from a schematic site quality classification obtained through calculation. Consequently, each forest type has its own development series with regard to the stand characteristics.

The number of forest types in the whole country is rather high. However, the different forest types are limited to different parts cf the country in such a way that there is no need for more than 5–6 forest types and 4 northerly sub-forms (-types) in each region, except in the border areas between the regions. In Finland the forest types have been the basis of forest site classification in forest research and practical forestry over a period of half a century. In pointing out the necessity of further study of forest types, Cajander has stressed the examination of differences in the compositions of vegetation between different classes of density of tree-stand and building up average descriptions of vegetation in such classes in young, middle-age and old stands. The same may be caused by some other factors which also are of essential influence to the composition of the vegetation.

The PDF includes a summary in English.

  • Ilvessalo, E-mail: yi@mm.unknown (email)
  • Ilvessalo, E-mail: mi@mm.unknown
article id 7574, category Article
Olavi Isomäki. (1974). Sahateollisuuden kuorintajätteiden käyttömahdollisuudet. Erityisesti käyttö maanparannusaineena ja kasvualustana. Acta Forestalia Fennica no. 140 article id 7574. https://doi.org/10.14214/aff.7574
English title: Using possibilities of barking waste in sawmill industry specially using as a soil improver and substrate for plants.
Original keywords: sahateollisuus; raaka-aine; selluteollisuus; hyötykäyttö; kuorintajäte; maanparannusaine
English keywords: bark; recycling; waste wood; sawmill industry; pulp industry; raw material; soil improvement; barking waste
Abstract | View details | Full text in PDF | Author Info

Residue of the wood is good raw material for pulp and board industries, but the question of the use of barking waste still remains to a great extent unsolved. This research deals with the possibilities to utilize the barking waste of sawmill industry in general and, in particular, its use as a soil improver and substrate for plants. It also explains the industrial manufacturing method of composted bark, bark humus, developed by the author as well as the properties of bark humus and the economy of bark humus and the economy of manufacturing.

The PDF includes a summary in Finnish.

  • Isomäki, E-mail: oi@mm.unknown (email)
article id 7572, category Article
Tauno Kallio, Pekka Tamminen. (1974). Decay of spruce (Picea abies (L.) Karst.) in the Åland Islands. Acta Forestalia Fennica no. 138 article id 7572. https://doi.org/10.14214/aff.7572
Keywords: Norway spruce; Picea abies; timber quality; Heterobasidion annosum; pulpwood; decay; Fomes annosus; Armillaria mellea; injuries; timber trees
Abstract | View details | Full text in PDF | Author Info

In 1972, all Norway spruce (Picea abies (L.) H. Karst.) trees of a minimum 7 cm diameter at breast height growing in the sample plots of the Sixth National Forest Inventory were examined on the main island of Aland, Finland. The soundness of standing trees was estimated by means of external characteristics and increment borer chips. The trees were then felled and measured. They were cut into lengths, and the type and extent of decay were studied.

30% of the trees examined was affected by butt rot, ca. 3% by wound decay. A comparison of the results with those of the Sixth National Forest Inventory justifies the estimate that in Aland 23% of spruce trees exceeding 7 cm in diameter at 1.3 m had butt rot.

The proportion of decayed trees in the cubic volume was 31%. Decayed wood material accounted for 5% of the volume including bark. Butt rot increased towards the mature stands. The reduction in the number of timber trees due to decay was 14.5%, in their volume 21.5%, and in the volume of sulphite pulpwood 12%. The share of sulphate pulpwood increased from 1 to 10%. The total reduction in usable wood was 6.3%. The stumpage price of the trees fell by 10.3%. As the degree of decay increased the increment percentage of the trees decreased. The most common cause of butt rot was Fomes annosus (Heterobasidion annosum) found in 46% of the number of decayed trees. Armillaria mellea was found in 16%. Bacteria were found in 50% of the decayed trees.

The PDF includes a summary in Finnish.

  • Kallio, E-mail: tk@mm.unknown (email)
  • Tamminen, E-mail: pt@mm.unknown
article id 7571, category Article
Tauno Kallio. (1974). Bacteria isolated from injuries to growning spruce trees (Picea abies (L.) Karst.). Acta Forestalia Fennica no. 137 article id 7571. https://doi.org/10.14214/aff.7571
Keywords: wood; Heterobasidion annosum; Stereum sanguinolentum; Phlebiopsis gigantea; bacteria; Fomes annosus; microbes; injuries; antagonists; Peniophora gigantea
Abstract | View details | Full text in PDF | Author Info

Infection of living Norway spruce (Picea abies (L.) H. Karst.) trees by bacteria, and the properties of these bacteria were studied. Bacterial antagonism to three decay fungi was also studied in laboratory conditions.

Bacteria could be found in 26% of all spruce injuries. Bacterial infection was most frequent in injuries made in March–April and June, and least frequent in December–February. Bacteria infected most often sapwood injuries in roots above soil level, 55% of the bacterial colonies were isolated from these injuries. 27% of the colonies were isolated from injuries made by increment borer at breast height, extending to heartwood, 16% from sapwood injuries at breast height, and 2% from injuries at stump height. The main bacterial groups were gram-positive rods (55%) and gram-negative rods (29%).

In 65% of the bacteria the metabolism was fermentative, in 14% slowly fermentative, in 7% oxidative, in 8% slowly oxidative, and in 6% alkalizing. 19% utilized cellulose, 15% in the presence of organic, 3% in the presence of inorganic nitrogen.

One bacterial strain was the only micro-organism growing in the injury a year after the damage, although the injury had been infected with Peniophora gigantea (Phlebiopsis gigantea). In laboratory experiments, this rod bacterium, gram-negative strain proved to be antagonistic to Fomes annosus (Heterobasidion annosum), Stereum sanguinolentum and P. gigantea. It had no capacity for cellulose utilization.

The PDF includes a summary in Finnish.

  • Kallio, E-mail: tk@mm.unknown (email)
article id 7570, category Article
Antti Isomäki, Tauno Kallio. (1974). Consequences of injury caused by timber harvesting machines on the growth and decay of spruce (Picea abies (L.) Karst.). Acta Forestalia Fennica no. 136 article id 7570. https://doi.org/10.14214/aff.7570
Keywords: logging; Heterobasidion annosum; Stereum sanguinolentum; decay; wood harvesting; stem damage; fellings; Fomes annosus; root damage
Abstract | View details | Full text in PDF | Author Info

The study material was collected from 10 localities in South Finland in 1971–72. The material comprised 816 damaged Norway spruce (Picea abies (L.) H. Karst.) trees with a total of 978 injuries.

Decay (discoloration) spread upward from the damaged point was about three times as fast as downward. The mean rate of advance upward was 21 cm/year. The decay spreading at the quickest rate started from above-ground root collar injuries. The size of the damaged area (surface area, width and depth) correlated positively with the rate of increase in decay initiated by the injury. For the first 10 years the decay advanced at the same rate after which the advance became slower though not ceasing. Damage produced in the early summer caused a faster spread of decay than that produced in the late summer or winter. The rate of advance was the greater the larger the stem involved. When decay started from trunk damage its rate of advance was greater the faster the growth of the trees. With a better soil type, the rate of advance in decay increased. Fertilization increased the rate of advance.

The widest stem injuries reduced tree growth by about one-third, and severed roots by nearly half of the growth of trees where the width of the injuries was 0–4 cm. Fomes annosus (Heterobasidion annosum) infected spruce injuries especially in the southern coastal district. The farthest tips of discoloration proved in most cases to be sterile. The most common fungus isolated from these sites was Stereum sanguinolentum.

The PDF includes a summary in Finnish.

  • Isomäki, E-mail: ai@mm.unknown (email)
  • Kallio, E-mail: tk@mm.unknown
article id 7537, category Article
Yrjö Roitto. (1970). Fuelwood consumption in the city of Monrovia ( Liberia) in 1965. Acta Forestalia Fennica no. 103 article id 7537. https://doi.org/10.14214/aff.7537
Keywords: firewood; fuelwood; Monrovia; Liberia; use of fuelwood
Abstract | View details | Full text in PDF | Author Info

This paper deals with fuelwood consumption in the city of Monrovia (Liberia) in 1965. Buyers of fuelwood were interviewed at market places, relevant data were recorded, and the average size of fuelwood bundles was measured by applying Archimedes Law.

The results showed that the annual average consumption of fuelwood per caput was 1.3 solid m3, and by household 6.5–6.6 solid m3. The average annual per caput expenditure on fuelwood was $ 9.7. This corresponds to a household of about 5 persons and means a household (family) expenditure of slightly less than $ 50 per annum, which is about 8% of the total household costs. Applying the Monrovia data to the whole of Liberia, it was estimated that fuelwood consumption in the whole country was 1.62 million m3 in 1965.

The PDF includes a summary in Finnish.

  • Roitto, E-mail: yr@mm.unknown (email)
article id 7607, category Article
Eino Oinonen. (1969). The time table of vegetative spreading of the lily-of-the-valley (Convallaria majalis L.) and the wood small-reed (Calamagrostis epigeios (L.) Roth) in southern Finland. Acta Forestalia Fennica no. 97 article id 7607. https://doi.org/10.14214/aff.7607
Keywords: regeneration; forest fire; Calamagrostis epigeios; lily-of-the-valley; Convallaria majalis; wood small-reed
Abstract | View details | Full text in PDF | Author Info

The purpose of this study has been to compile a time-table for the vegetative spreading o the lily-of-the-valley and the wood small-reed. The diameters of the mainly solitary stands of these species have been compared to stand diameters of bracken (Lycopodium clavatum, L. annotium, and L. complanatum), to tree age determined by basal borings, and to times of fires in the site.

Regeneration of the lily-of-the-valley (Convallaria Majalis L.) and the wood small-reed (Calamagrostis epigeios (L.) Roth) from seed is relatively infrequent, and distance between stands may be considerable. Regeneration is more common after fire. The stands of the species are relatively fire resistant, especially on heathlands, where the subsurface parts are safe in the mineral soil. Large stands are generally due to vegetative spreading.

The rate of vegetative spreading of both of the species is practically constant, and about equal, 12.5 cm/year in diameter and 6.2 cm/year in the radial direction. When the actual regeneration time after the fire is not known, the rate of the spreading can be lower than this number.

  • Oinonen, E-mail: eo@mm.unknown (email)
article id 7603, category Article
Olli Makkonen. (1969). Ancient forestry : A historical study. Part II, The procurement and trade of forest products. Acta Forestalia Fennica no. 95 article id 7603. https://doi.org/10.14214/aff.7603
Keywords: logging; timber trade; history; wood transportation; roman times
Abstract | View details | Full text in PDF | Author Info

The present paper presents a study on the works of ancient writers that deal with trees, forests and the use of forests before the time of actual forest sciences. The work describes the development of knowledge pertaining to the forest and trees and the progress made on utilizing them. This second part of a series of two articles is concerned with logging, transportation and trade of timber, as well as procurement and trade of other forest products. These activities have been practiced as long as the history of mankind is known.

The article introduces the most important ancient written sources from the standpoint of the subject of the article, and related modern literature. The second part describes the texts concerning felling and primary conversion, and skidding and transportation. The third part concentrates on timber trade, and the fourth on the procurement and trade of other forest products.

  • Makkonen, E-mail: om@mm.unknown (email)

Category : Research article

article id 23040, category Research article
Jānis Liepiņš, Ieva Jaunslaviete, Kaspars Liepiņš, Līga Jansone, Roberts Matisons, Andis Lazdiņš, Āris Jansons. (2023). Effect of stem rot on wood basic density, carbon, and nitrogen content of living deciduous trees in hemiboreal forests. Silva Fennica vol. 57 no. 3 article id 23040. https://doi.org/10.14214/sf.23040
Keywords: wood specific gravity; birch; climate change mitigation; biomass estimation; alder; aspen; wood decay
Highlights: Stem rot significantly reduces the basic density of wood and increases its nitrogen content in living deciduous trees, while the carbon content appears irresponsive; The effect of the distance from the pith on the basic density and nitrogen content of wood varies, depending on presence of discoloration or decomposition in the wood.
Abstract | Full text in HTML | Full text in PDF | Author Info
While numerous studies have focused on analyzing various aspects of the carbon (C) budget in forests, there appears to be a lack of comprehensive assessments specifically addressing the impact of stem rot on the C budget of broadleaf tree species, especially in old-growth forests where stem rot is prevalent. One of the main challenges in accurately quantifying C losses caused by stem rot is the lack of precise data on the basic density and C content of decayed wood, which are crucial for converting decayed wood volume into biomass and C stocks. Using linear mixed-effects models, we examine the variability of wood basic density, C content, and nitrogen (N) content. Discolored and decomposed wood was collected from the stems of 136 living deciduous trees common in hemiboreal forests in Latvia. Our research indicates a noticeable reduction in the wood basic density, coupled with an increase in the N content within the stem wood throughout the decomposition process in birch (Betula spp.), European aspen (Populus tremula L.), grey alder (Alnus incana (L.) Moench), and common alder (Alnus glutinosa (L.) Gaertn.). While aspen wood showed a decreasing trend in C content as decay progressed, a pairwise comparison test revealed no significant differences in C content between discolored and decomposed wood for the studied species, unlike the findings for basic density and N content. This study emphasizes the need to account for stem rot in old-growth forest carbon budgets, especially in broadleaf species, and calls for more research on stem rot-induced carbon losses.
  • Liepiņš, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia ORCID https://orcid.org/0000-0003-3030-1122 E-mail: janis.liepins@silava.lv (email)
  • Jaunslaviete, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia ORCID https://orcid.org/0009-0000-7322-2729 E-mail: ieva.jaunslaviete@silava.lv
  • Liepiņš, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia ORCID https://orcid.org/0000-0002-1179-8586 E-mail: kaspars.liepins@silava.lv
  • Jansone, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia ORCID https://orcid.org/0000-0003-2748-3797 E-mail: liga.jansone@silava.lv
  • Matisons, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia E-mail: roberts.matisons@silava.lv
  • Lazdiņš, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia ORCID https://orcid.org/0000-0002-7169-2011 E-mail: andis.lazdins@silava.lv
  • Jansons, Latvian State Forest Research Institute “Silava,” Rigas Street 111, LV-2169 Salaspils, Latvia ORCID https://orcid.org/0000-0001-7981-4346 E-mail: aris.jansons@silava.lv
article id 10767, category Research article
Semo Mogeia, Alberto A. Manhiça, Andrade F. Egas. (2023). Wood ash content variation in Eucalyptus grandis clones in Mozambique. Silva Fennica vol. 57 no. 1 article id 10767. https://doi.org/10.14214/sf.10767
Keywords: sapwood; heartwood; base-top; bioenergy quality; woody fuel
Highlights: Eucalyptus grandis heartwood produces better fuel than sapwood, if assuming ash content as energy quality parameter; Younger individuals have higher ash content in sapwood, and older individuals in the heartwood; There was not significant stem end variation of ash content in heartwood and sapwood.
Abstract | Full text in HTML | Full text in PDF | Author Info

The sustainability of native forests in Sub-Saharan Africa depends on the diversification of sources to generate bioenergy, and Eucalyptus spp. wood has been highlighted. However, the determination of energy quality parameters has been a challenge to enable plantation wood to generate energy. The research assessed the ash content of radial and longitudinal samples of Eucalyptus grandis (Hill) clone with different ages and growth sites. Samples were collected in three pre-established plots in the center of Mozambique. Five trees were cut down in each plot and six discs were removed from each tree. Grinded samples with <0.5 mm particle size were generated from the heartwood and sapwood of each disk to determine the ash content. Wood from 7-year-olds had a higher ash content compared to 9-year-olds. The two sample plots differed from each other in terms of wood ash content. Heartwood samples had smaller ash content than sapwood samples. In general, the ash content of the intermediate positions was lower than those from the base and top of the stem, for both radial sections. No conclusive differences were found between samples from the base and the top of the trees, indicating that the material from the top of the trees can also be used as wood fuel. Ash content can be a considerable parameter to assess the quality of the wood of Eucalyptus spp. as a fuel.

  • Mogeia, Universidade Lúrio, Faculdade de Ciências Agrárias, Departamento de Silvicultura e Maneio [Lurio University, Faculty of Agricultural Sciences, Department of Forestry and Management], Campus de Wanaango, EN733, Km 42, Unango, Niassa, Mozambique E-mail: smogeia@unilurio.ac.mz (email)
  • Manhiça, Centro de Investigação Florestal, [Forestry Research Center], Marracuene, EN1, Maputo província, Mozambique E-mail: albertomanhica@gmail.com
  • Egas, Universidade Eduardo Mondlane, Faculdade de Agronomia e Engenharia Florestal, Departamento de Florestas, [Eduardo Mondlane University, Faculty of Agronomy and Forestry Engineering, Department of Forests], Av. Julius Nyerere, Maputo cidade, Mozambique E-mail: aegas8@gmail.com
article id 10660, category Research article
Åsa Gustafsson, Jimmy Johansson. (2022). Identifying present drivers of product development and describing roles of identified actors primarily affecting the development of harvesters: a multiple-case study. Silva Fennica vol. 56 no. 3 article id 10660. https://doi.org/10.14214/sf.10660
Keywords: forest operations; logging contractor; industry driver; interview; softwood lumber supply chain
Highlights: Legislators, logging contractors, and expert and research organizations are present drivers of product development of harvesters; They appear to prioritize meeting legal regulations and lowering costs for logging contractors as they outline requirements for manufacturing harvesters.
Abstract | Full text in HTML | Full text in PDF | Author Info

Forest operations involve several different actors. Each actor imposes their own requirements on the harvester in relation to their differing roles in the industry, whether they are concerned with the harvester itself, information, environmental concerns, etc. The manufacturers of harvesters need to meet the requirements imposed by multiple actors, among them logging contractors, whose survival depends on their harvesters. This paper aims to identify the present drivers of product development and describe the roles of the actors who have been identified as those currently affecting the development of harvesters. A multiple-case study of harvester manufacturers was conducted. In total, 4 cases were studied. Each case was comprised of five interviewees: two from each harvesting manufacturer, two logging contractors, and one dealer. Following 20 interviews and 3 validation interviews (with experts from both the industry and academia), the paper concludes that the present drivers of product development of harvesters are legislators, logging contractors, and expert and research organizations. Harvester manufacturers appear to develop harvesters aligned with requirements coming from both logging contractors and legislators. Logging contractors are the primary customers, and they prioritize requirements that reduce cost and improve work environments. Legislators, and expert and research organizations are supporting development in relation to current regulations.

  • Gustafsson, Department of Accounting and Logistics, Linnaeus University, Universitetsplatsen 1, 352 52 Växjö, Sweden E-mail: asa.gustafsson@lnu.se (email)
  • Johansson, Department of Forestry and Wood Technology, Linnaeus University, 391 82 Kalmar, Sweden E-mail: jimmy.johansson@lnu.se
article id 10550, category Research article
Miro Demol, Phil Wilkes, Pasi Raumonen, Sruthi M. Krishna Moorthy, Kim Calders, Bert Gielen, Hans Verbeeck. (2022). Volumetric overestimation of small branches in 3D reconstructions of Fraxinus excelsior. Silva Fennica vol. 56 no. 1 article id 10550. https://doi.org/10.14214/sf.10550
Keywords: aboveground biomass; crown architecture; LIDAR; quantitative structure models; common ash; woody tree volume
Highlights: We compare branch diameter and tree woody volume estimates from terrestrial laser scanning data with manual measurements of two Fraxinus excelsior trees; Smaller branch diameters are generally overestimated due to scattering and misalignment errors in the point cloud; Consequently, tree woody volume is overestimated by 38% to 52%; Filtering by reflectance and improved alignment partly mitigate this effect.
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Terrestrial laser scanning (TLS) has been applied to estimate forest wood volume based on detailed 3D tree reconstructions from point cloud data. However, sources of uncertainties in the point cloud data (alignment and scattering errors, occlusion, foliage...) and the reconstruction algorithm type and parameterisation are known to affect the reconstruction, especially around finer branches. To better understand the impacts of these uncertainties on the accuracy of TLS-derived woody volume, high-quality TLS scans were collected in leaf-off conditions prior to destructive harvesting of two forest-grown common ash trees (Fraxinus excelsior L.; diameter at breast height ~28 cm, woody volume of 732 and 868 L). We manually measured branch diameters at 265 locations in these trees. Estimates of branch diameters and tree volume from Quantitative Structure Models (QSM) were compared with these manual measurements. The accuracy of QSM branch diameter estimates decreased with smaller branch diameters. Tree woody volume was overestimated (+336 L and +392 L) in both trees. Branches measuring < 5 cm in diameter accounted for 80% and 83% of this overestimation respectively. Filtering for scattering errors or improved coregistration approximately halved the overestimation. Range filtering and modified scanning layouts had mixed effects. The small branch overestimations originated primarily in limitations in scanner characteristics and coregistration errors rather than suboptimal QSM parameterisation. For TLS-derived estimates of tree volume, a higher quality point cloud allows smaller branches to be accurately reconstructed. Additional experiments need to elucidate if these results can be generalised beyond the setup of this study.

  • Demol, CAVElab – Computational and Applied Vegetation Ecology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; PLECO – Plants and Ecosystems, Faculty of Science, Antwerp University, Universiteitsplein 1, B-2610 Wilrijk, Belgium ORCID https://orcid.org/0000-0002-5492-2874 E-mail: miro.demol@ugent.be (email)
  • Wilkes, UCL Department of Geography, Gower Street, London WC1E 6BT, UK; NERC National Centre for Earth Observation (NCEO), UK ORCID https://orcid.org/0000-0001-6048-536X E-mail: p.wilkes@ucl.ac.uk
  • Raumonen, Mathematics, Tampere University, FI-33101 Tampere, Finland ORCID https://orcid.org/0000-0001-5471-0970 E-mail: pasi.raumonen@tuni.fi
  • Krishna Moorthy, CAVElab – Computational and Applied Vegetation Ecology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium ORCID https://orcid.org/0000-0002-6838-2880 E-mail: Sruthi.KrishnaMoorthyParvathi@ugent.be
  • Calders, CAVElab – Computational and Applied Vegetation Ecology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium ORCID https://orcid.org/0000-0002-4562-2538 E-mail: kim.calders@ugent.be
  • Gielen, PLECO – Plants and Ecosystems, Faculty of Science, Antwerp University, Universiteitsplein 1, B-2610 Wilrijk, Belgium ORCID https://orcid.org/0000-0002-4890-3060 E-mail: bert.gielen@uantwerpen.be
  • Verbeeck, CAVElab – Computational and Applied Vegetation Ecology, Department of Environment, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium ORCID https://orcid.org/0000-0003-1490-0168 E-mail: hans.verbeeck@ugent.be
article id 10605, category Research article
Charlotta Harju, Katja Lähtinen. (2021). Perceptions of wooden interior product quality – insights on sustainability views among Finnish consumers. Silva Fennica vol. 55 no. 5 article id 10605. https://doi.org/10.14214/sf.10605
Keywords: wood products; consumer behavior; perceived quality; sociodemographic variables; sustainable consumption
Highlights: The quality indicators of wooden interior products can be grouped into four factors relating to products’ environmental friendliness, fit with lifestyle and home design, visual and tactile attractiveness, and technical solidity, which are in multiple ways connected with sustainability; The sociodemographic background of the respondents was found to be linked with consumer scores for those factors; Wooden interior products should be designed to meet different types of product quality expectations in the home environment.
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Evaluation of product attributes and the overall quality significantly affect consumer purchasing decisions. Previous studies on wooden products have mostly addressed wood product quality from technical viewpoints, while largely disregarding environmental, social, and economic aspects in the assessments. Therefore, knowledge on how sustainability aspects are evaluated as a feature of wood product quality is narrow. This study investigated consumer perceptions of different quality indicators (i.e., quality cues and attributes) of wooden interior products with a special focus on sustainability and value chain phases. In addition, the connections between consumers’ sociodemographic background and their perceptions of the quality features of wooden interior products were evaluated. The material of the study was based on data gathered in 2018 with a postal survey sent to 1000 people living in Finland with a response rate of 25.6%. As methods of analysis, exploratory factor analysis, the Mann-Whitney U test, and the Kruskall-Wallis test were utilized. The results show that the quality indicators of wooden interior products can be grouped into four factors relating to products’ environmental friendliness, fit with lifestyle and home design, visual and tactile attractiveness, and technical solidity, which are in multiple ways connected with sustainability. The sociodemographic background of the respondents was found to be linked with consumer scores for those factors. Engaging consumers in sustainable consumption choices requires providing them with information on wooden product value chains that meets their individual needs in relation to their existing knowledge of those issues and individual values.
 

  • Harju, University of Vaasa, School of Marketing and Communication, P.O. Box 700, FI-65200 Vaasa, Finland ORCID https://orcid.org/0000-0002-0432-2598 E-mail: charlotta.harju@uwasa.fi (email)
  • Lähtinen, Natural Resources Institute Finland (Luke), Bioeconomy and Environment Unit, P.O. Box 2, FI-00790 Helsinki, Finland ORCID https://orcid.org/0000-0001-6260-5062 E-mail: katja.lahtinen@luke.fi
article id 10525, category Research article
Markus Melin, Tiina Ylioja, Leena Aarnio, Katri Hamunen, Seppo Nevalainen, Antti Pouttu, Heli Viiri. (2021). Emergence levels of pine shoot beetles from roundwood piles of Scots pine and the cascading damage in the surrounding forests. Silva Fennica vol. 55 no. 5 article id 10525. https://doi.org/10.14214/sf.10525
Keywords: forest management; forestry; Tomicus piniperda; Tomicus minor; roundwood; legislation; timber storage
Highlights: Emerged pine shoot beetles were counted from piles of harvested Scots pine, and the shoot damage in the surrounding forests was measured; Damage was noticeable up to a distance of 40–60 m, being more severe near large piles; For piles smaller than 50 m3 the level of damage (fallen shoots) was mainly below known thresholds for growth losses; Logs with harvester-damaged bark were significantly less colonized by the beetles.
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Bark beetles are amongst the most aggressive pest agents of coniferous forests. Due to this, many boreal countries have designated laws aiming to lower the risk of bark beetle epidemics. Finland’s forest legislation has pre-emptive measures targeted against bark beetles, and for Scots pine (Pinus sylvestris L.), the law concerns pine shoot beetles (Tomicus spp.). This study used data collected around 25 piles of Scots pine roundwood that were harvested in the winter but left in the forest until the following November. Thus, the pine shoot beetles were able to use the piles for breeding. We assessed the number of emerged insects from the piles and the cascading damage they caused in the surrounding forests. All roundwood piles, regardless of their volume, were used by the beetles for breeding. Highest densities of beetle exit holes were found from the parts of the log with thick and intact bark. If the bark of the log was damaged by the harvester head, the number of beetles decreased significantly. Depending on the volume of the roundwood pile, the cascading damage (fallen shoots) was noticeable up to ca. 40–60 m from the roundwood pile. Storing of piles smaller than 50 m3 did not cause excess damage. The number of fallen shoots per tree was generally below the known thresholds for when growth losses can occur. However, the study was conducted in mature forests, and it can be assumed that the recorded damage levels would severely affect the growth of young pines, raising the question of where to store the roundwood. As with other bark beetles, the role of Tomicus beetles as damage agents may change in the future, but based on this as well as past studies, the species can be viewed as a notable damage agents only around long-term wood storage sites in the current northern conditions.

  • Melin, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6b, FI-80100 Joensuu, Finland E-mail: markus.melin@luke.fi (email)
  • Ylioja, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: tiina.ylioja@luke.fi
  • Aarnio, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: leena.aarnio@luke.fi
  • Hamunen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6b, FI-80100 Joensuu, Finland E-mail: katri.hamunen@luke.fi
  • Nevalainen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6b, FI-80100 Joensuu, Finland E-mail: seppo.nevalainen@gmail.com
  • Pouttu, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: antti.pouttu@kolumbus.fi
  • Viiri, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6b, FI-80100 Joensuu, Finland; UPM-Kymmene Oyj, UPM Forest, Peltokatu 26 C, PL 85, FI-33100, Tampere, Finland E-mail: heli.viiri@upm.com
article id 10539, category Research article
Jaakko Repola, Juha Heikkinen, Jari Lindblad. (2021). Pulpwood green density prediction models and sampling-based calibration. Silva Fennica vol. 55 no. 4 article id 10539. https://doi.org/10.14214/sf.10539
Keywords: pulpwood; conversion factor; green density
Highlights: The developed models provided a realistic description of the observed seasonal variation in pulpwood green density; The model predictions were more reliable than those obtained with current practices.
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Pulpwood arriving at the mills is mainly measured by weighing. In the loading phase of forwarding and trucking, timber is weighed using scales mounted in the grapple loader. The measured weight of timber is converted into volume using a conversion factor defined as green density (kg m–3). At the mill, the green density factor is determined by sampling measurements, while in connection with weighing with grapple-mounted scales during transportation, fixed green density factors are used. In this study, we developed predictive regression models for the green density of pulpwood. The models were constructed separately by pulpwood assortments: pine (contains mainly Pinus sylvestris L); spruce (mainly Picea abies (L.) Karst.); decayed spruce; birch (mainly Betula pubescens Ehrh. and Betula pendula Roth); and aspen (mainly Populus tremula L.). Study material was composed of the sampling-based measurements at the mills between 2013–2019. The models were specified as linear mixed models with both fixed and random parameters. The fixed effect produced the expected value of green density as a function of delivery week, storage time, and meteorological conditions during storage. The random effects allowed the model calibration by utilizing the previous sampling weight measurements. The model validation showed that the model predictions faithfully reproduced the observed seasonal variation in green density. They were more reliable than those obtained with the current practices. Even the uncalibrated (fixed) predictions had lower relative root mean squared prediction errors than those obtained with the current practices.

  • Repola, Natural Resources Institute Finland (Luke), Natural resources, Ounasjoentie 6, 96200 Rovaniemi, Finland E-mail: jaakko.repola@luke.fi (email)
  • Heikkinen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: juha.heikkinen@luke.fi
  • Lindblad, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: jari.lindblad@luke.fi
article id 10441, category Research article
Dipak Mahatara, Amul K. Acharya, Bishnu P. Dhakal, Dipesh K. Sharma, Sunita Ulak, Prashant Paudel. (2021). Maxent modelling for habitat suitability of vulnerable tree Dalbergia latifolia in Nepal. Silva Fennica vol. 55 no. 4 article id 10441. https://doi.org/10.14214/sf.10441
Keywords: rosewood; satisal; distribution mapping; environmental variables; Maxent modelling
Highlights: Dalbergia latifolia is a vulnerable species of Nepal with very few conservation priorities; Habitat suitability modelling for this species is essential to endorse different conservation interventions; 43 presence locations and different environmental variables were retained for model prediction in Maxent; Province 2 was found most suitable habitat for the growth of D. latifolia, with western most province as unsuitable.
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Dalbergia latifolia Roxb., commonly known as rosewood, is one of the highly valuable tropical timber species of Nepal. The tree species was widely distributed in the past, however, over-exploitation of natural habitat, deforestation, forest conversion for agriculture, illegal logging and the invasion of alien species resulted in the classification of this species as vulnerable by the IUCN (International Union for Conservation of Nature) category. So, the prediction of habitat suitability and potential distribution of the species is required to develop restoration mechanisms and conservation interventions. In this study, we modelled the suitable habitat of D. latifolia over the entire possible range of Nepal using a Maxent model. We compiled 23 environmental variables (19 bioclimatic, 3 topographic and a vegetative layer), however, only 12 least correlated variables along with 43 spatially representative presence locations were retained for model prediction. We used a receiver operating characteristic (ROC) curve to assess the model’s performance and a Jackknife procedure to evaluate the relative importance of predictor variables. The model was statistically significant with an area under the curve (AUC) value of 0.969. The internal Jackknife test indicated that elevation was the most important variable for the model prediction with 71.3% contribution followed by mean temperature of driest quarter (9.8%). The most (>0.6) suitable habitat for the D. latifolia was 235 484 hectares with large sections of area in two provinces whereas, the western most provinces were not suitable for D. latifolia as per Maxent model. The information presented here can provide a framework for nature conservation planning, monitoring and habitat management of this rare and endangered species.

  • Mahatara, Forest Research and Training Centre, Government of Nepal, P.O. Box 3339, Babarmahal, Kathmandu 44600, Nepal E-mail: honeystar73@gmail.com (email)
  • Acharya, Forest Research and Training Centre, Government of Nepal, P.O. Box 3339, Babarmahal, Kathmandu 44600, Nepal E-mail: acharya.amulkumar@gmail.com
  • Dhakal, Forest Research and Training Centre, Government of Nepal, P.O. Box 3339, Babarmahal, Kathmandu 44600, Nepal E-mail: dhakalbp.shorea@gmail.com
  • Sharma, Forest Research and Training Centre, Government of Nepal, P.O. Box 3339, Babarmahal, Kathmandu 44600, Nepal E-mail: dipeshsharmadiyu2015@gmail.com
  • Ulak, Forest Research and Training Centre, Government of Nepal, P.O. Box 3339, Babarmahal, Kathmandu 44600, Nepal E-mail: sunitaulak@gmail.com
  • Paudel, Agriculture Forestry University, P.O. Box 13712 Rampur, Chitwan, Nepal E-mail: prashant.paudel88@gmail.com
article id 10555, category Research article
Ferréol Berendt, Felix Wolfgramm, Tobias Cremer. (2021). Reliability of photo-optical measurements of log stack gross volume. Silva Fennica vol. 55 no. 3 article id 10555. https://doi.org/10.14214/sf.10555
Keywords: photogrammetry; timber trade; logistic; volume estimation; wood pile
Highlights: Gross volume estimations of larger log stacks showed a smaller deviation compared to those of piles with smaller volumes; Log stack quality affects estimation accuracy; The deviations between the manual section-wise estimations were of similar amplitude as those for the photo-optical estimations.
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In terms of assessing economic impact, one of the most important elements in the wood supply chain is the measurement of round wood. Besides the one-by-one measurement of logs, logs are often measured when stacked at the forest road. The gross stacked volume includes the volume of the wood, bark and airspace and is widely used for industrial wood assortments. The increasing international attention given to photo-optical measurement systems for portable devices is due to their simplicity of use and efficiency. The aim of this study was to compare the gross volumes of hardwood log stacks measured using one widespread photo-optical app with two manual section-wise volume estimations of log stacks based on the German framework agreement for timber trade (RVR). The manual volume estimations were done starting from the left (RVRleft) and right (RVRright) sides of the log stacks. The results showed an average deviation of the photo-optical gross volume estimation in comparison to the manual estimation of –2.09% (RVRleft) and –3.66% (RVRright) while the deviation between RVRleft and RVRright was +2.54%. However, the log stack gross volume had a highly significant effect on the deviation and better accuracy with smaller deviation were reached for larger log stacks. Moreover, results indicated that the gross volume estimations of higher quality log stacks were closer for the three analyzed methods compared to estimations of poor-quality log stacks.

  • Berendt, Department of Forest Utilization and Timber Markets, Eberswalde University for Sustainable Development, 16225 Eberswalde, Germany ORCID https://orcid.org/0000-0002-6285-7590 E-mail: ferreol.berendt@hnee.de (email)
  • Wolfgramm, Landesforst MV Anstalt des öffentlichen Rechts, Forstamt Billenhagen, 18182 Blankenhagen, Germany E-mail: felixwolfgramm@yahoo.de
  • Cremer, Department of Forest Utilization and Timber Markets, Eberswalde University for Sustainable Development, 16225 Eberswalde, Germany E-mail: tobias.cremer@hnee.de
article id 10545, category Research article
Karol Tomczak, Tomczak Arkadiusz, Bartłomiej Naskrent, Tomasz Jelonek. (2021). The radial gradient of moisture content of silver birch wood in different seasons. Silva Fennica vol. 55 no. 3 article id 10545. https://doi.org/10.14214/sf.10545
Keywords: birch; Betula pendula; wood properties; living trees; seasonal changes; trunk cross section
Highlights: Seasonal variation in moisture content is significant, the greatest moisture content of wood was recorded in winter, and the lowest in summer; The greatest moisture content on cross-section was observed near to the pith, and lower values near to the bark; From environmental perspective results of this study may have an impact for log transport planning, weight-scaling systems, lumber drying.
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Silver birch (Betula pendula Roth) is classified in diffuse-porous wood category. In this case structure of wood tissue is quite similar across whole cross-sectional area. The aim of this study was to analyse cross-section variability of moisture content (MC) of growing silver birch wood, significant hardwood species in Polish forests. Investigations were performed on 120 model trees. In the trunk of each model tree, an increment core was collected at breast height. Samples were collected of 30 different trees in four different seasons. The greatest MC was observed during winter, lowest MC in summer. Differences in MC were statistically significant only between winter versus spring, summer, and autumn. Distribution of MC on cross-section was similar in each season. The greatest average value was observed close to pith, then it was decreasing in bark direction. The greatest difference between observed in spring – 19.51% (p < 0.05) and lowest in autumn – 4.66%. Distribution of green density (GD) on cross section was inverse proportional to MC value. Variations in GD and MC are relevant for log transport planning, weight-scaling systems, lumber drying and dynamic assessment of stiffness. Therefore, from an environmental loss perspective, it is important to determine changes in MC and GD across the year.

  • Tomczak, Department of Forest Utilization, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 71A, 60-625 Poznań, Poland ORCID https://orcid.org/0000-0001-5192-0294 E-mail: karol.tomczak@up.poznan.pl (email)
  • Arkadiusz, Department of Forest Utilization, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 71A, 60-625 Poznań, Poland ORCID https://orcid.org/0000-0003-1140-8282 E-mail: arkadiusz.tomczak@up.poznan.pl
  • Naskrent, Department of Forest Utilization, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 71A, 60-625 Poznań, Poland ORCID https://orcid.org/0000-0002-0756-4162 E-mail: bartlomiej.naskrent@up.poznan.pl
  • Jelonek, Department of Forest Utilization, Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Wojska Polskiego 71A, 60-625 Poznań, Poland ORCID https://orcid.org/0000-0001-9558-9951 E-mail: tomasz.jelonek@up.poznan.pl
article id 10391, category Research article
Victoria A.M. Poljatschenko, Lauri T. Valsta. (2021). Carbon emissions displacement effect of Finnish mechanical wood products by dominant tree species in a set of wood use scenarios. Silva Fennica vol. 55 no. 1 article id 10391. https://doi.org/10.14214/sf.10391
Keywords: avoided emissions; mechanical forest industry; substitution effect; wooden construction
Highlights: Wood product consumption patterns are combined with production-based displacement factors to estimate displacement factors for logs by tree species; The main tree species in Finland have somewhat unequal displacement factors; Historical and projected wood use scenarios show large variation in the levels of avoided emissions between individual years and scenarios.
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The carbon emissions displacement effect of Finnish logs for mechanical wood products by dominant tree species (Scots pine, Pinus sylvestris L.; Norway spruce, Picea abies (L.) H. Karst.; Birch, Betula spp.) was assessed by combining information from previous studies of current consumption patterns with displacement factors (DF) for structural construction, non-structural construction, and energy usage. We did not conduct additional life cycle analyses compared to the current literature. Our aim was to identify the factors that most extensively influence the displacement effect and to estimate the overall climate effect of Finnish logs in light of current production levels of mechanical forest industry. The analyses were based on information from both statistics and proprietary sources. Contrary to previous studies, we provide DFs by main tree species in Finland, which has been an unidentified area of research to date. Additionally, we apply a more detailed classification of structural and non-structural wood products. This study did not include effects on the forest carbon sink, as they depend case-wise on forest resources and forest management. According to our results, with current production and consumption trends, the average displacement effects for domestic Scots pine, Norway spruce, and birch logs were 1.28, 1.16, and 1.43 Mg C/Mg C, respectively. The corresponding overall annual displacement effect caused by the current production of sawn wood and wood-based panels was 12.3 Tg CO2 for Finland for the BAU scenario and varied between 8.6 and 16.3 Tg CO2 depending on the wood use scenario.

  • Poljatschenko, Simosol Oy, Hämeenkatu 10, FI-11100 Riihimäki, Finland E-mail: victoria.poljatschenko@simosol.fi (email)
  • Valsta, Department of Forest Sciences, University of Helsinki, Latokartanonkaari 7, FI-00014 University of Helsinki, Finland E-mail: lauri.valsta@helsinki.fi
article id 10379, category Research article
Juha Laitila, Kari Väätäinen. (2020). Productivity of harvesting and clearing of brushwood alongside forest roads. Silva Fennica vol. 54 no. 5 article id 10379. https://doi.org/10.14214/sf.10379
Keywords: logging; energy wood; time study; harwarder; spiral cutter; whole-trees
Highlights: The results can be used as a basis to determine in what kinds of cases brushwood biomass should be recovered and where it should be left to decay; The average volume of harvested brushwood and forwarding distance are the key elements to harvesting productivity with a harwarder; Stump diameter has a strong impact on clearing productivity of brushwood.
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Expertise in the cost-efficient utilization and treatment of brushwood on forest roadside sites is limited. In the present study, the productivity of brushwood clearing and harvesting on forest roadside sites was defined by creating time-consumption models or parameters for the aforementioned working methods. Compiled time consumption models and parameters for the brushwood clearing and harvesting can be used as a basis for evaluating alternative management practices and to determine when brushwood biomass should be harvested and when it should be left to decay. The harvesting of brushwood was based on the harwarder system and the clearing of brushwood was done with a spiral cutter, which is a novel accessory for cutting roadside vegetation. Based on the study results, the average volume of harvested brushwood and forwarding distance are the key elements that have an effect on harvesting productivity with harwarders. Correspondingly, stump diameter has a strong impact on the clearing productivity of brushwood. The plot-wise productivity of the spiral cutter in brushwood clearings varied in the range of 0.19–0.61 ha per PMh. An increase in stump diameter slowed down the clearing productivity of the spiral cutter and there was a clear step downward in clearing productivity as the average diameter increased from 30 mm to 40 mm. The machinery under study operated well and there were no interruptions due to machine breakdowns.

  • Laitila, Natural Resources Institute Finland (Luke), Production systems, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juha.laitila@luke.fi (email)
  • Väätäinen, Natural Resources Institute Finland (Luke), Production systems, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: kari.vaatainen@luke.fi
article id 10392, category Research article
Paula Jylhä, Pasi Rikkonen, Katri Hamunen. (2020). Size matters – an analysis of business models and the financial performance of Finnish wood-harvesting companies. Silva Fennica vol. 54 no. 4 article id 10392. https://doi.org/10.14214/sf.10392
Keywords: profitability; business model; business model canvas; entrepreneur; success factor; wood-harvesting enterprise
Highlights: Economic success was related to company’s size, Small companies with a turnover of less than 600 000 € a–1 are struggling with profitability; Large enterprises continue to grow and innovate new business concepts; The competitive edge of large companies was reflected in large production capacity, efficient operations, versatile supply of services, and power in negotiations.
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The size of Finnish wood harvesting enterprises has grown, and entrepreneurs have become responsible for various additional tasks, resulting in networking with other harvesting enterprises of various sizes and suppliers of supporting services, but the profitability of the wood harvesting sector has remained low. In the present study, the financial performance of 83 wood harvesting companies in Eastern and Northern Finland was evaluated, based on public final account data from a five-year period between 2013 and 2017. The factors underlying economic success were identified based on 19 semi-structured entrepreneur interviews. The Business Model Canvas framework was applied in the analyses. In particular, the smallest companies (with an annual turnover of less than 600 000 €) struggled with profitability. They showed increasing indebtedness, suffered from poor power in negotiations, had typically short-term contracts, and faced difficulties in retaining skilled operators. Most of the small companies were subcontractors of larger wood-harvesting companies. The better economic success of larger companies was likely based on their capacity to provide wood harvesting services in large volumes and supply versatile services, power in negotiations, and more cost-effective operations. The future development of wood harvesting seems to be polarised: larger enterprises are likely to continue growing, while the size of smaller enterprises has stabilised. Enhancing business management skills and practices is required in enterprises of all size groups.

  • Jylhä, Natural Resources Institute Finland (Luke), Production systems, Teknologiakatu 7, FI-67100 Kokkola, Finland E-mail: paula.jylha@luke.fi (email)
  • Rikkonen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland E-mail: pasi.rikkonen@luke.fi
  • Hamunen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Yliopistokatu 6B, FI-80100 Joensuu, Finland E-mail: katri.hamunen@luke.fi
article id 10205, category Research article
Michel Soucy, Martin Béland. (2020). A crop tree release variant of precommercial thinning using a backpack mounted chain saw. Silva Fennica vol. 54 no. 3 article id 10205. https://doi.org/10.14214/sf.10205
Keywords: thinning; hardwood; spacing; time study; brushsaw; motor-manual; work performance
Highlights: Backpack mounted chain saws offer an opportunity to effectively cut larger stems in precommercial thinning treatments compared to conventional circular blade brushsaws; Productivity in performing precommercial crop tree release (PCTR) in a hardwood stand using a backpack mounted chain saw varied between 0.22 to 0.47 ha h–1.
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Although crop tree release (CTR) in hardwood stands is an accepted variant of precommercial thinning (PCT), the lack of an affordable and feasible method hinders its adoption. CTR implies selecting between 150 and 500 trees ha–1 when trees are between 7 and 12 m high and cutting only stems competing with the target crop trees. We performed a field trial of a CTR variant of PCT in a 27.8 ha hardwood stand using a backpack mounted chain saw. A detailed time study was performed to document the trial over 13 days. Compared to conventional PCT performed earlier in the life of a stand, precommercial crop tree release required cutting larger stems, which showed to be feasible and productive using a backpack mounted chain saw. Productivity varied between 0.22 to 0.47 ha h–1 during the trial, Although productivity could vary with stand characteristics and worker, this proof of concept trial demonstrates some of the potential uses that this new saw configuration offers and sets the basis for an eventual larger scale deployment of this treatment.

article id 10259, category Research article
Jyrki Hytönen, Hannu Hökkä. (2020). Comparison of granulated and loose ash in fertilisation of Scots pine on peatland. Silva Fennica vol. 54 no. 2 article id 10259. https://doi.org/10.14214/sf.10259
Keywords: Pinus sylvestris; wood ash; nutrition; fertilisation; granulation; PK fertiliser
Highlights: Granulated ash and commercial PK fertilizer increased stand growth in similar way during 15-year study period; Loose ash gave stronger and faster response than granulated ash.
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The effects of wood ash fertilisation on tree nutrition and growth on forested peatlands has been studied using loose ash, but in practice, ash fertilisation is done almost exclusively with granulated ash. In this study, the effects of granulated ash and loose ash (both 5 Mg ha–1) on the growth and nutrition of Scots pine (Pinus sylvestris L.) stands were compared between a nitrogen-poor and a nitrogen-rich site over 15 years. On the nitrogen-rich site, wood ash application was also compared with commercial PK fertilisation. On the nitrogen-rich site, mean stand volume growth increase over unfertilised control treatment during the 15 year study period using granulated ash and commercial PK fertiliser was of the same magnitude (on average, 2.2–2.3 m3 ha–1 a–1). However, when loose ash was used growth increase over control was higher (3.7 m3 ha–1 a–1). On the nitrogen-poor site, the mean growth increase gained by loose or granulated ash (1.4–1.5 m3 ha–1 a–1) over the unfertilised control treatment was not significant. Fertilisation with loose ash or PK increased foliar P, K and B concentrations already in the first or second growing season, following fertilisation on both sites. Granulated ash increased foliar P concentrations on the nitrogen-rich site less than loose ash. After an initial increase, foliar P, K and B concentrations decreased at the end of study period. On the nitrogen-poor site, foliar P concentrations were below the deficiency limit by the end of the study period.

  • Hytönen, Natural Resources Institute Finland, Natural Resources, Teknologiakatu 7, FI-67100 Kokkola, Finland ORCID https://orcid.org/0000-0001-8475-3568 E-mail: jyrki.hytonen@luke.fi (email)
  • Hökkä, Natural Resources Institute Finland, Natural Resources, Paavo Havaksentie 3, FI-90570 Oulu, Finland E-mail: hannu.hokka@luke.fi
article id 10084, category Research article
Mihails Čugunovs, Eeva-Stiina Tuittila, Jari Kouki. (2020). Proximity to charred logs in burned forests likely affects decomposition processes in the soil. Silva Fennica vol. 54 no. 1 article id 10084. https://doi.org/10.14214/sf.10084
Keywords: coarse woody debris; forest fire; prescribed burning; cellulose decomposition; tea-bag method
Highlights: Standardised organic substrate decomposition was tentatively observed to be faster adjacent to non-charred downed logs than away from the logs or adjacent to charred logs; A spatial linkage was observed between non-charred logs and decomposition in the soil in burned boreal forests; Proximity to a charred log may provide a micro-environment where decomposition rates differ from the surrounding forest soil.
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We studied the spatial decomposition rates of standardised organic substrates in soils (burned boreal pine-dominated sub-xeric forests in eastern Finland), with respect to charred and non-charred coarse woody debris (CWD). Decomposition rates of rooibos plant litter inside teabags (C:N = 42.870 ± 1.841) and pressed-sheet Nordic hardwood pulp (consisting of mainly alpha-cellulose) were measured at 0.2 m distance from 20 charred (LC0.2) and 40 non-charred logs (LNC0.2). We also measured decomposition at 60 plots located 3–10 m away from downed logs (L3,10). The rooibos decomposition rate constant ‘k’ was 8.4% greater at the LNC0.2 logs than at the L3,10 or LC0.2 logs. Cellulose decomposed more completely in 1 micron mesh bags at LNC0.2 (44% of buried bags had leftover material) than at LC0.2 (76%) or L3,10 (70%). Decomposition of cellulose material was rapid but varied greatly between sampling plots. Our results indicate that decomposition of the standardised organic matter was more rapid close to CWD pieces than further away. However, only the plots located near non-charred logs (LNC0.2) exhibited high decomposition rates, with no corresponding increase observed at the charred logs (LC0.2). This suggests a possible noteworthy indirect effect of forest burning on soil organic matter (SOM) decomposition rates close to charred CWD after forest fires. We urge for more studies on this tentative observation as it may affect the estimates on how fires affect carbon cycling in forests.

  • Čugunovs, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: mihails.cugunovs@gmail.com (email)
  • Tuittila, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID https://orcid.org/0000-0001-8861-3167 E-mail: eeva-stiina.tuittila@uef.fi
  • Kouki, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID https://orcid.org/0000-0003-2624-8592 E-mail: jari.kouki@uef.fi
article id 10151, category Research article
Jyri Hietala, Riitta Hänninen, Matleena Kniivilä, Anne Toppinen. (2019). Networks in international opportunity recognition among Finnish wood product industry SMEs. Silva Fennica vol. 53 no. 4 article id 10151. https://doi.org/10.14214/sf.10151
Keywords: wood products; business networks; institutional networks; internationalization; opportunity recognition; social networks
Highlights: In line with earlier literature, we found the networks in our study to positively impact international opportunity recognition; Despite the reliance on various network forms and levels, a strategic stance towards opportunity recognition can be characterized as being more reactive than proactive; Institutional networks represented a more systematic way of recognizing international opportunities among case companies.
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Bioeconomy development will create new opportunities for firms operating in the international wood products markets, and identifying and exploiting these opportunities is emphasized as a key concept to achieving business success. Our study will attempt to address a gap in the literature on sawmill industry business development from the viewpoint of international opportunity recognition. The aim of our study is to provide a holistic description on how small and medium-sized enterprises (SMEs) in the wood products industry recognize and exploit international business opportunities, and how they utilize network perspectives in this context. The subject was examined through Finnish wood product industry SMEs by interviewing 11 managers and industry representatives. The results suggest that SMEs recognize international opportunities reactively per se. Social networks formed in professional forums were an important information channel for identifying international opportunities. Through vertical business networks, such as sales agents, firms have been able to increase their international market presence and free their own resources for other important activities. Horizontal dyadic business networks were seen to facilitate new international opportunities through cooperation, while excessive reliance on vertical networks raised concerns and seemed not to be effective in international opportunity recognition. Institutional networks formed a systematic way of recognizing international opportunities, but more so at the initial market entry stage.

  • Hietala, United Bankers, Aleksanterinkatu 21 A, FI-00100 Helsinki, Finland E-mail: jyri.hietala@unitedbankers.fi (email)
  • Hänninen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: riitta.hanninen@luke.fi
  • Kniivilä, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: matleena.kniivila@luke.fi
  • Toppinen, University of Helsinki, Helsinki Institute of Sustainability Science, Latokartanonkaari 7, P.O. 27, FI-00014 University of Helsinki, Finland E-mail: anne.toppinen@helsinki.fi
article id 10010, category Research article
Panu Halme, Jenna Purhonen, Emma-Liina Marjakangas, Atte Komonen, Katja Juutilainen, Nerea Abrego. (2019). Dead wood profile of a semi-natural boreal forest – implications for sampling. Silva Fennica vol. 53 no. 4 article id 10010. https://doi.org/10.14214/sf.10010
Keywords: coarse woody debris; coniferous forest; forest structure; fine woody debris; forest disturbance dynamics; saproxylic
Highlights: We constructed a full dead wood profile of a semi-natural boreal forest; Abundance-diameter distributions were different among tree species; Extensive sampling is needed if focus on large dead wood and rare tree species.
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Dead wood profile of a forest is a useful tool for describing forest characteristics and assessing forest disturbance history. Nevertheless, there are few studies on dead wood profiles, including both coarse and fine dead wood, and on the effect of sampling intensity on the dead wood estimates. In a semi-natural boreal forest, we measured every dead wood item over 2 cm in diameter from 80 study plots. From eight plots, we further recorded dead wood items below 2 cm in diameter. Based on these data we constructed the full dead wood profile, i.e. the overall number of dead wood items and their distribution among different tree species, volumes of different size and decay stage categories. We discovered that while the number of small dead wood items was immense, their number dropped drastically from the diameter below 1 cm to diameters 2–3 cm. Different tree species had notably different abundance-diameter distribution patterns: spruce dead wood comprised most strikingly the smallest diameter fractions, whereas aspen dead wood comprised a larger share of large-diameter items. Most of the dead wood volume constituted of large pieces (>10 cm in diameter), and 62% of volume was birch. The variation in the dead wood estimates was small for the numerically dominant tree species and smallest diameter categories, but high for the sub-dominant tree species and larger size categories. In conclusion, the more the focus is on rare tree species and large dead wood items, the more comprehensive should the sampling be.

  • Halme, Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland; School of Resource Wisdom, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: panu.halme@jyu.fi (email)
  • Purhonen, Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: jenna.e.i.purhonen@jyu.fi
  • Marjakangas, Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway E-mail: emma-liina.marjakangas@ntnu.no
  • Komonen, Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland; School of Resource Wisdom, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: atte.komonen@jyu.fi
  • Juutilainen, Department of Biological and Environmental Science, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: kjuutilainen@yahoo.com
  • Abrego, Department of Agricultural Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: nerea.abrego@helsinki.fi
article id 10048, category Research article
Urszula Zajączkowska, Karina Kaczmarczyk, Janusz Liana. (2019). Birch sap exudation: influence of tree position in a forest stand on birch sap production, trunk wood anatomy and radial bending strength. Silva Fennica vol. 53 no. 2 article id 10048. https://doi.org/10.14214/sf.10048
Keywords: biomechanics; wood anatomy; forest edge; xylem sap
Highlights: Birch trees along the forest edge exude more xylem sap but less concentrated than the trees from the interior; Radial bending strength of wood in birch trunk is higher in the trees from forest edge; Trees exhibit higher bending strength in western side of the trunk, where the number of vessels and the wood potential conductivity index are smaller.
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It is commonly accepted that the period of early-spring xylem sap exudation marks a stage during which a positive pressure builds inside the tree trunks. This state changes when leaves appear, initiating water transport within the trunk. It is unknown, however, how the wood anatomical structure and its mechanical resistance influences the sap. We present the results of research on the relationship between exudation of sap from Betula pendula Roth trees from the interior of a forest stand and from its edge, and the anatomical structure of the trunk wood and its bending strength. During the period between March 21 and April 18, we performed five sets of measurements of sap exudation from trees at the edge of the stand and from the forest interior. The resulting radial wood samples were tested for bending strength using a fractometer. We tested the sap for electrolytic conductivity and sugars content. For the anatomical analysis of the wood, we determined the number of vessels per 1 mm2, average vessel lumen area and potential conductivity index. We found that the trees along the edge of the stand exude more sap, but it is less concentrated than the sap from the trees from the interior. Bending strength perpendicular to wood fibres is higher in the trees from the stand edge and in the western side of the trunk, where the number of vessels per 1 mm2 and conductivity index are smaller. Seemingly, this is the result of western winds, which are dominant in Poland.

  • Zajączkowska, Department of Forest Botany, Faculty of Forestry, Warsaw University of Life Sciences, 159 Nowoursynowska St., 02-776 Warsaw, Poland E-mail: urszula.zajaczkowska@wl.sggw.pl (email)
  • Kaczmarczyk, Department of Forest Botany, Faculty of Forestry, Warsaw University of Life Sciences, 159 Nowoursynowska St., 02-776 Warsaw, Poland E-mail: karina.kaczmarczyk@wl.sggw.pl
  • Liana, Department of Forest Botany, Faculty of Forestry, Warsaw University of Life Sciences, 159 Nowoursynowska St., 02-776 Warsaw, Poland E-mail: janusz.liana@wl.sggw.pl
article id 9968, category Research article
Hubert Lachowicz, Anna Bieniasz, Rafał Wojtan. (2019). Variability in the basic density of silver birch wood in Poland. Silva Fennica vol. 53 no. 1 article id 9968. https://doi.org/10.14214/sf.9968
Keywords: Betula pendula; tree age; forest habitat type; thickness of trees; geographical location; physical properties of wood
Highlights: Location, tree age and forest habitat type, and the interactions between those factors, have a statistically significant impact on the basic density of silver birch wood; The average basic density of silver birch wood increases with the age of the tree.
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This work presents the findings of a study concerning variability in the basic density of silver birch (Betula pendula Roth) wood, depending on the geographical location of tree stands, the age and thickness of the trees, the forest habitat type, and interactions between some of these factors. The study was carried out on wood from trees aged approximately 30, 50 and 70 years in 12 forest districts located throughout Poland. In total 4777 wood samples, taken from 306 trees from 51 test plots, were measured. The location, the age of the trees, the thickness of the trees and the forest habitat type, as well as interactions between these factors, proved to have a significant influence on the basic density of silver birch wood. The highest mean values of the basic density of the birch wood were found in Sokołów forest district on the FBF habitat type (549 kg m–3) and in Giżycko forest district on the FMBF habitat type (548 kg m–3). For the entire set of examined material, the average values of the basic density of wood increase with tree age. For the examined material originating in FBF and FMBF habitats the average values of basic density showed no significant differences; however, in the cases of the forest districts of Giżycko, Łobez and Rudziniec, significant differences in the analysed property were observed.

  • Lachowicz, Department of Forest Utilization, Warsaw University of Life Sciences SGGW, Nowoursynowska 159 02-787 Warsaw, Poland E-mail: hubert.lachowicz@wl.sggw.pl
  • Bieniasz, Department of Forest Utilization, Warsaw University of Life Sciences SGGW, Nowoursynowska 159 02-787 Warsaw, Poland E-mail: anna.bieniasz@wl.sggw.pl (email)
  • Wojtan, Laboratory of Dendrometry and Forest Productivity, Warsaw University of Life Sciences SGGW, Nowoursynowska 159 02-787 Warsaw, Poland E-mail: rwojtan@wl.sggw.pl
article id 10001, category Research article
Karoliina Hämäläinen, Teemu Tahvanainen, Kaisa Junninen. (2018). Characteristics of boreal and hemiboreal herb-rich forests as habitats for polypore fungi. Silva Fennica vol. 52 no. 5 article id 10001. https://doi.org/10.14214/sf.10001
Keywords: biodiversity; species richness; coarse woody debris; threatened species; wood-decaying fungi
Highlights: Polypore species richness and diversity were affected positively by dead-wood diversity, and negatively by increasing latitude; Red-listed species responded only to the abundance of large-diameter dead wood; Main factor determining composition of polypore assemblages was host-tree species; High proportion of deciduous dead-wood in herb-rich forests provides complementary effect on polypore assemblages in boreal forest landscapes.
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Herb-rich forests are often considered biodiversity hotspots in the boreal zone but their fungal assemblages, particularly those of wood-decaying fungi, remain poorly known. We studied herb-rich forests as habitats for polypores, a distinct group of wood-decaying fungi, and assessed the importance of tree- and stand-scale variables for polypore species richness, abundance, and diversity, including red-listed species. The data include 71 herb-rich forest stands in Finland and 4797 dead wood items, on which we made 2832 observations of 101 polypore species. Dead-wood diversity was the most important variable explaining polypore species richness and diversity, whereas increasing latitude had a negative effect. Red-listed species showed a positive response to the abundance of large-diameter dead wood, which, especially birch, supported also high general abundance of polypores. The composition of polypore assemblages reflected their host-tree species. The red-listed species did not show explicit patterns in the ordination space. Compared to old-growth spruce forests, herb-rich forests seem to host lower polypore species richness and less red-listed species. However, because of high proportion of deciduous trees in the dead wood profile, herb-rich forests have a clear complementary effect on polypore assemblages in boreal forest landscapes.

  • Hämäläinen, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: karoham@uef.fi (email)
  • Tahvanainen, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: teemu.tahvanainen@uef.fi
  • Junninen, Metsähallitus Parks & Wildlife Finland, c/o UEF/Borealis, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: kaisa.junninen@metsa.fi
article id 9938, category Research article
Jyrki Hytönen, Egbert Beuker, Anneli Viherä-Aarnio. (2018). Clonal variation in basic density, moisture content and heating value of wood, bark and branches in hybrid aspen. Silva Fennica vol. 52 no. 2 article id 9938. https://doi.org/10.14214/sf.9938
Keywords: moisture content; wood; bark; hybrid aspen; basic density; branches; clonal variation; heating value; ash content
Highlights: Hybrid aspen clones differed in their moisture content, ash content, basic density and heating value; Stem wood had lower ash content, basic density and effective heating value than stem bark; There was significant vertical variation in wood and bark along the stem in moisture content and basic density.
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Hybrid aspen (Populus tremula × P. tremuloides) is one of the fastest growing tree species in Finland. During the mid-1990s, a breeding programme was started with the aim of selecting clones that were superior in producing pulpwood. Hybrid aspen can also be grown as a short-rotation crop for bioenergy. To study clonal variation in wood and bark properties, seven clones were selected from a 12-year-old field trial located in southern Finland. From each clone, five trees were harvested and samples were taken from stem wood, stem bark and branches to determine basic density, effective heating value, moisture and ash content. Vertical within-tree variation in moisture content and basic density was also studied. The differences between clones were significant for almost all studied properties. For all studied properties there was a significant difference between wood and bark. Wood had lower ash content (0.5% vs. 3.9%), basic density (378 kg m–3 vs. 450 kg m–3) and effective heating value (18.26 MJ kg–1 vs. 19.24 MJ kg–1), but higher moisture content (55% vs. 49%) than bark. The values for branches were intermediate. These results suggest that the properties of hybrid aspen important for energy use could be improved by clonal selection. However, selecting clones based on fast growth only may be challenging since it may lead to a decrease in hybrid aspen wood density.

  • Hytönen, Natural Resources Institute Finland (Luke), Natural resources, Teknologiakatu 7, FI-67100 Kokkola, Finland E-mail: jyrki.hytonen@luke.fi (email)
  • Beuker, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 6, FI-57200 Savonlinna, Finland E-mail: egbert.beuker@luke.fi
  • Viherä-Aarnio, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: anneli.vihera-aarnio@luke.fi
article id 9914, category Research article
Jun Tanabe, Futoshi Ishiguri, Akira Tamura, Yuya Takashima, Jyunichi Ohshima, Kazuya Iizuka, Shinso Yokota. (2018). Within-tree radial and among-family variations in wood density, microfibril angle, and mechanical properties in Picea glehnii. Silva Fennica vol. 52 no. 2 article id 9914. https://doi.org/10.14214/sf.9914
Keywords: modulus of elasticity; modulus of rupture; early selection; tree breeding for wood quality
Highlights: The modulus of elasticity was affected by both microfibril angle and wood density, whereas the modulus of rupture was mainly affected by wood density in Picea glehnii; A larger degree of among-family variation in wood properties was detected in juvenile wood than in mature wood, indicating that genetic improvements in the mechanical properties may be more effective for juvenile wood.
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Genetic improvements in the mechanical properties of wood are important in forestry species used for lumber, such as Picea. The within-tree radial and among-family variations for the modulus of elasticity (MOE), modulus of rupture (MOR), and their related traits [i.e., microfibril angle (MFA) of the S2 layer in latewood tracheid and air-dry density (AD)] were evaluated in nine open-pollinated families of Picea glehnii (F. Schmidt) Mast. The radial variation in MOR was mainly affected by AD, whereas MOE was affected by MFA and AD. Higher F-values obtained by analysis of variance and coefficient of variation were observed for all properties at the 6th–15th annual ring, except for AD at the 6th–10th annual ring. This result suggests that the contribution of genetic effect is larger in these highly variable regions. In addition, positive correlation coefficients were obtained between wood properties at the 6th–15th annual ring and mean values of these properties. Therefore, genetic improvements for MOE, MOR, and their related traits in P. glehnii is likely to be more effective in juvenile wood, specifically at the 6th–15th annual ring from the pith.

  • Tanabe, Faculty of Education, Chiba University, Chiba, 263-8522, Japan E-mail: tanabe_j@chiba-u.jp (email)
  • Ishiguri, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan E-mail: ishiguri@cc.utsunomiya-u.ac.jp
  • Tamura, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Hitachi, 319-1301, Japan E-mail: akirat@affrc.go.jp
  • Takashima, Forest Tree Breeding Center, Forestry and Forest Products Research Institute, Hitachi, 319-1301, Japan E-mail: ytakashima@ffpri.affrc.go.jp
  • Ohshima, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan E-mail: joshima@cc.utsunomiya-u.ac.jp
  • Iizuka, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan E-mail: kiizuka@cc.utsunomiya-u.ac.jp
  • Yokota, Faculty of Agriculture, Utsunomiya University, Utsunomiya 321-8505, Japan E-mail: yokotas@cc.utsunomiya-u.ac.jp
article id 9902, category Research article
Perttu Anttila, Vesa Nivala, Olli Salminen, Markus Hurskainen, Janne Kärki, Tomi J. Lindroos, Antti Asikainen. (2018). Regional balance of forest chip supply and demand in Finland in 2030. Silva Fennica vol. 52 no. 2 article id 9902. https://doi.org/10.14214/sf.9902
Keywords: bioenergy; energy wood; GIS; availability; potential
Highlights: The impact of increasing forest chip demand in 2030 was analyzed in Finland; Demand of small trees may exceed potential at the national level; Surplus potential will remain in logging residues and stumps; Hot spots of demand call for efficient logistical solutions.
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According to the National Energy and Climate Strategy of Finland in 2016, the demand for forest chips, that is, wood chips made of forest biomass directly for energy use, could even double by 2030 compared to the present situation. A spatially explicit impact analysis of regional supply and demand balances for forest chips was carried out. The balances were calculated as the difference between technical harvesting potentials and demand. First, the technical potentials were estimated based on the national forest inventory data. Secondly, three demand scenarios were defined for 2030 and subsequently deducted from the potentials. The results suggested that there would be increasing competition for feedstock in southern and western Finland, whereas in eastern and northern Finland there would still be surplus potential. Moreover, due to the remarkable deficit of small trees in southern Finland, there might be pressure towards using more pulpwood-sized and/or imported wood in energy production. The results also showed that, in particular, large new plants consuming substantial amounts of forest chips could have a significant effect on the regional availability of forest chips. Moreover, with increasing transport distances, new logistical solutions will be needed.

  • Anttila, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID http://orcid.org/0000-0002-6131-392X E-mail: perttu.anttila@luke.fi (email)
  • Nivala, Natural Resources Institute Finland (Luke), Eteläranta 55, FI-96300 Rovaniemi, Finland E-mail: vesa.nivala@luke.fi
  • Salminen, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: olli.salminen@luke.fi
  • Hurskainen, VTT Technical Research Centre of Finland Ltd, Koivurannantie 1, FI-40400 Jyväskylä, Finland E-mail: markus.hurskainen@vtt.fi
  • Kärki, VTT Technical Research Centre of Finland Ltd, Koivurannantie 1, FI-40400 Jyväskylä, Finland E-mail: janne.karki@vtt.fi
  • Lindroos, VTT Technical Research Centre of Finland Ltd, Vuorimiehentie 3 (Espoo), P.O. Box 1000, FI-02044 VTT, Finland E-mail: tomi.j.lindroos@vtt.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: antti.asikainen@luke.fi
article id 7830, category Research article
Jari Lindblad, Johanna Routa, Johanna Ruotsalainen, Marja Kolström, Ari Isokangas, Lauri Sikanen. (2018). Weather based moisture content modelling of harvesting residues in the stand. Silva Fennica vol. 52 no. 2 article id 7830. https://doi.org/10.14214/sf.7830
Keywords: logging residues; harvesting residues; energy wood measurement; conversion factor
Highlights: Weather data used for estimating the moisture content of energy wood; The validation of the weather based models performed based on the field data.
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Harvesting residues collected from the final cuttings of boreal forests are an important source of solid biofuel for energy production in Finland and Sweden. In the Finnish supply chain, the measurement of residues is performed by scales integrated in forwarders. The mass of residues is converted to volume by conversion factors. In this study, weather based models for defining the moisture content of residues were developed and validated. Models were also compared with the currently used fixed tables of conversion factors. The change of the moisture content of residues is complex, and an exact estimation was challenging. However, the model predicting moisture change for three hour periods was found to be the most accurate. The main improvement compared to fixed tables was the lack of a systematic error. It can be assumed that weather based models will give more reliable estimates for the moisture in varying climate conditions and the further development of models should be focused on obtaining more appropriate data from varying drying conditions in different geographical and microclimatological locations.

  • Lindblad, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: jari.lindblad@luke.fi (email)
  • Routa, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: johanna.routa@luke.fi
  • Ruotsalainen, Finnish Meteorological Institute, Aviation and Military Weather Services, P.O. Box 1627, FI-70211 Kuopio, Finland E-mail: johanna.ruotsalainen@fmi.fi
  • Kolström, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: marja.kolstrom@uef.fi
  • Isokangas, University of Oulu, Control Engineering, P.O. Box 8000, FI-90014 University of Oulu, Finland E-mail: ari.isokangas@oulu.fi
  • Sikanen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: lauri.sikanen@luke.fi
article id 7791, category Research article
Tadeusz B. Splawinski, Sylvie Gauthier, Nicole J. Fenton, Daniel Houle, Yves Bergeron. (2018). The colonization of young fire initiated stands by the crustose lichen Trapeliopsis granulosa and its potential effect on conifer establishment and stand succession. Silva Fennica vol. 52 no. 1 article id 7791. https://doi.org/10.14214/sf.7791
Keywords: establishment; Pinus banksiana; forest ecology; lichen woodland; stand succession.; Trapeliopsis granulosa
Highlights: T. granulosa is a poor seedbed for jack pine establishment; The presence of extensive T. granulosa cover can limit ongoing tree recruitment, thereby maintaining open lichen woodland; Dry open conditions favor the establishment of T. granulosa; Stands with significant T. granulosa cover may be good candidates for afforestation initiatives due to lower evaporation potential and decreased water stress.
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The resilience of closed-crown coniferous stands within the boreal forest of North America is highly dependent on successful re-establishment of tree species following fire. A shift from closed-crown forest to open lichen woodland is possible following poor natural regeneration during the initial establishment phase, followed by the development of extensive lichen cover, which may hinder ongoing recruitment. We examined the development of the crustose lichen Trapeliopsis granulosa (Hoffm.) 18 to 21 years following fire within six sites in the boreal forest of northwestern Quebec, and explored its potential to affect ongoing recruitment during early successional stages of stand development. Germination and survivorship trials were conducted within the laboratory to determine the establishment rate of Pinus banksiana Lamb. (jack pine) on T. granulosa, mineral soil, and burnt duff under two separate watering frequencies (observed and drought). Survival and establishment rates of jack pine were highest on burnt duff, and poor on both T. granulosa and mineral soil. Under the drought treatment, no seedlings survived on any substrates. In the field, T. granulosa cover had a positive relationship with mineral soil cover, and negative relationships with duff cover, ericaceous shrub cover, organic layer depth, other lichen cover, and Sphagnum moss cover. No discernable relationship was found between T. granulosa and tree density, rock cover, dead wood cover or other moss cover. The development of extensive T. granulosa cover in fire-initiated stands can impede ongoing recruitment of conifer species due to its poor seedbed quality, thereby maintaining open forests.

  • Splawinski, Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, 445, boul. de l’Université, Rouyn-Noranda, QC, J9X 5E4, Canada E-mail: tsplawinski@gmail.com (email)
  • Gauthier, Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 rue du PEPS, P.O. Box 10380, Stn Sainte Foy, QC, G1V 4C7, Canada E-mail: sylvie.gauthier@rncan-nrcan.gc.ca
  • Fenton, Institut de recherche sur les forêts (IRF), Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC, J9X 5E4, Canada E-mail: nicole.fenton@uqat.ca
  • Houle, Ministère des Forêts, de la Faune et des Parcs, Direction de la recherché forestière, Québec, QC, G1P 3W8, Canada; Ouranos Climate Change Consortium, Montréal, QC, H3A 1B9, Canada E-mail: daniel.houle@mffp.gouv.qc.ca
  • Bergeron, Centre d’étude sur la forêt and Chaire industrielle en aménagement forestier durable, Université du Québec à Montréal, CP 8888 Succursale A, Montréal, QC, H3C 3P8, Canada E-mail: bergeron.yves@uqam.ca
article id 7003, category Research article
Poje Anton, Raffaele Spinelli, Natascia Magagnotti, Matevz Mihelic. (2018). The effect of feedstock, knife wear and work station on the exposure to noise and vibrations in wood chipping operations. Silva Fennica vol. 52 no. 1 article id 7003. https://doi.org/10.14214/sf.7003
Keywords: biomass; fuelwood; ergonomics; safety
Highlights: Exposure to noise and vibration is higher when chipping branches rather than logs; Noise levels are higher in the separate cab, especially at some frequencies; Vibration is higher for the Z axis in the separate cab, for the X axis in the truck; Noise is higher when working with blunt knives, rather than new knives; Knife wear has no significant effect on exposure to whole-body vibration.
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Industrial chipping is becoming increasingly popular, as the result of a growing demand for woody biomass. Industrial chippers are large, powerful machines that generate much noise and vibration. This study explored some factors that may affect exposure to noise and vibration, namely: feedstock type (branches vs. logs), work station characteristics (truck cab vs. separate cab) and knife wear (new knives vs. blunt knives). Exposure to noise was significantly affected by all three factors, and it was higher for branch feedstock, separate cabs and blunt knives. The higher exposure levels recorded for the separate cab were especially insidious, because they were below and above the hearing threshold and would elude immediate perception. Exposure to whole-body vibration (WBV) was significantly higher for branch feedstock and for the separate cab. Knife wear seemed to determine an increase in WBV, but this effect had no statistical significance and the result could not be taken as conclusive. Among the three factors studied, work station characteristics had the strongest effect. Further studies may extend the comparison to a wider range of options, as well as explore the use of exposure variation for machine diagnostics.

  • Anton, University of Ljubljana, Dept. of Forestry and Renewable Resources, Večna pot 83, 1000 Ljubljana, Slovenia E-mail: anton.poje@bf.uni-lj.si
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy; AFORA, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, Queensland, 4558 Australia ORCID http://orcid.org/0000-0001-9545-1004 E-mail: spinelli@ivalsa.cnr.it (email)
  • Magagnotti, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy; AFORA, University of the Sunshine Coast, Locked Bag 4, Maroochydore DC, Queensland, 4558 Australia E-mail: magagnotti@ivalsa.cnr.it
  • Mihelic, University of Ljubljana, Dept. of Forestry and Renewable Resources, Večna pot 83, 1000 Ljubljana, Slovenia E-mail: matevz.mihelic@bf.uni-lj.si
article id 6999, category Research article
Virginia Morales Olmos, Jacek P. Siry. (2018). The Law of One Price in global coniferous sawlog markets. Silva Fennica vol. 52 no. 1 article id 6999. https://doi.org/10.14214/sf.6999
Keywords: cointegration; roundwood prices; international trade
Highlights: The Law of One Price did not hold for North American, European and South American sawlog markets between 1995–2012; There are long-term relationships between some of the analyzed sawlog prices in these markets; The Law of One Price may hold between sawlogs traded in Sweden and Norway, Norway and Finland, and Canada West and US Northwest.
Abstract | Full text in HTML | Full text in PDF | Author Info

With progressing globalization of forest production, roundwood prices in different countries may follow similar trends. The Law of One Price (LOP) postulates that the price of a similar product should be the same in different markets when expressed in the same currency. The objectives of this research were (1) to test the LOP in selected coniferous sawlog markets, and (2) to analyze whether a common market – the European Union – leads to the existence of a single sawlog market. The analysis included Brazil, Chile, Finland, Germany, Norway, Poland, Russia Northwest, Sweden, the US South, the US Northwest, Canada East, and Canada West. The results suggest that some of the coniferous sawlog markets were cointegrated which means that they shared a long-term relationship even if in the short-term they do not necessarily adjust to each other. The LOP may hold between coniferous sawlog markets in Sweden and Norway from 1995 through 2012 when sawlog prices were expressed in USD, and in Norway and Finland for 2001–2012 for prices in EUR. Furthermore, the LOP may hold for North American markets in the West for 2004–2012.

  • Morales Olmos, Universidad de la República-Sede Tacuarembó, Ruta 5. km, 386.200, Tacuarembó, CP 45000, Uruguay E-mail: vmolmos@gmail.com (email)
  • Siry, Warnell School of Forestry and Natural Resources, University of Georgia, 180 E. Green Street, Athens, GA 30602-2152, USA E-mail: jsiry@uga.edu
article id 7731, category Research article
Anneli Viherä-Aarnio, Pirkko Velling. (2017). Growth, wood density and bark thickness of silver birch originating from the Baltic countries and Finland in two Finnish provenance trials. Silva Fennica vol. 51 no. 4 article id 7731. https://doi.org/10.14214/sf.7731
Keywords: Betula pendula; provenance; bark thickness; frost crack; seed transfer; wood basic density; wood discolouration
Highlights: Baltic origins of silver birch had significantly thicker bark than the Finnish ones; In terms of wood density, no consistent difference was detected between the Baltic and Finnish origins; Incidence of darkened core wood increased with increasing seed origin latitude; Frost cracks were most common in south Latvian origins grown in central Finland.
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Silver birch (Betula pendula Roth) seed origins from the Baltic countries and from Finland were compared in terms of growth, wood density, bark thickness and the incidence of darkened core wood, frost cracks and decay, and the effect of seed origin latitude was examined in two Finnish provenance trials. The material consisted of 21 stand and single tree origins ranging from latitudes 54° to 63°N from the Baltic countries and Finland. The trials, measured at the age of 22 years, were located at Tuusula (60°21´N), southern Finland and at Viitasaari (63°11´N), central Finland. The Baltic origins were superior to the Finnish ones in the southern trial regarding height, whereas in central Finland the Finnish origins grew better. There was no consistent difference between the Baltic and the Finnish group of origins in wood density. Bark thickness decreased with increasing seed origin latitude. The Baltic origins had significantly thicker bark than the Finnish origins. A moderate positive correlation was detected between the seed origin latitude and the incidence of darkened core wood in the southern trial, where the darkened core wood was more common in the Finnish origins than in the Baltic ones. The highest proportion of trees with frost cracks was detected in the south-western Latvian origins growing in central Finland. Seed transfers from the Baltic would have an increasing effect on the bark thickness of birch logs, but no or only minor effects on wood density. Based on our results, there is no reason to recommend the use of non-native Baltic seed origins in Finland instead of the native locally adapted seed sources.

  • Viherä-Aarnio, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 2, FI-00791 Helsinki, Finland E-mail: anneli.vihera-aarnio@luke.fi (email)
  • Velling, E-mail: pike.velling@phnet.fi
article id 7728, category Research article
Liam Donnelly, Sven-Olof Lundqvist, Conor O’Reilly. (2017). Inter- and intra-annual wood property variation in juvenile wood between six Sitka spruce clones. Silva Fennica vol. 51 no. 4 article id 7728. https://doi.org/10.14214/sf.7728
Keywords: productivity; wood properties; Picea sitchensis; clonal forestry; selective breeding; stem height
Highlights: Wood property differences resulted primarily from variation in the proportions of early- and latewood in each annual ring; Width of early- and latewood bands in each ring was found to be a more important determinant of juvenile wood quality than the characteristics of the cells within each band; Wood properties differed greatly between clones, suggesting that there is potential to improve juvenile wood properties through selective breeding.
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Increased growth rates have reduced rotation lengths, increasing the proportion of juvenile wood relative to mature wood, which may negatively affect mechanical performance of sawn timber. However, there is limited information available on the potential impact of breeding for vigour on juvenile wood in Sitka spruce (Picea sitchensis (Bong.) Carrière). In this study, the relationship between vigour (based on total height) and wood properties was investigated in six-year-old Sitka spruce clones grown in two replicated field trials in Ireland. Six clones were evaluated, two clones from each of three vigour (high, intermediate and low) classes. Discs were cut from the base of one ramet per replication for each clone to assess wood quality attributes. Radial tracheid width was significantly and positively correlated with ring width and height, and was negatively correlated with density. The wood of the most vigorous clone had significantly larger ring width with thinner cell walls and wider tracheids than all clones in the two other vigour classes, resulting in lower mean wood density. Latewood properties for all wood attributes measured differed significantly between the two sites. Wood property differences resulted primarily from variation in the proportions of early- and latewood in each annual ring. Additionally, the width of early- and latewood bands in each ring was found to be a more important determinant of juvenile wood quality than the characteristics of the cells within each band. Wood properties differed greatly between clones, suggesting that there is potential to improve juvenile wood properties through selective breeding.

  • Donnelly, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland E-mail: liam.donnelly@ucdconnect.ie (email)
  • Lundqvist, Innventia Ab, Drottning Kristinas väg 61, SE-114 86 Stockholm, Sweden E-mail: svenolof.lundqvist@innventia.com
  • O’Reilly, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland E-mail: conor.oreilly@ucd.ie
article id 2017, category Research article
Pentti Niemistö, Soili Kojola, Anssi Ahtikoski, Raija Laiho. (2017). From useless thickets to valuable resource? – Financial performance of downy birch management on drained peatlands. Silva Fennica vol. 51 no. 3 article id 2017. https://doi.org/10.14214/sf.2017
Keywords: forest management; Betula pubescens; thinning; energy wood; pulpwood; profitability; final cutting
Highlights: The most profitable management regimes for pulpwood and energy wood production in dense downy birch stands on drained peatlands include no thinnings, but final cutting at the stand age of 40–45 years as whole-tree harvesting, or as integrated harvesting of pulpwood and delimbed energy wood stems about 10 years later depending on applicable harvesting method; A competitive management regime is early precommercial thinning at 4 m dominant height to a density of 2500 stems per hectare and production of pulpwood with a rotation of 55–65 years. Equal profitability is achieved with or without traditional first thinning, which can thus be included for other reasons, for example to improve regeneration of spruce.
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Downy birch (Betula pubescens Ehrh.) stands on drained peatlands are often considered useless because they typically do not yield good-quality sawn timber. However, covering an area of ca. 0.5 million hectares and with total yields of up to 250 m3 ha–1, downy birch stands on peatlands in Finland have a potential for pulpwood and/or energy wood production. We examined the financial performance of alternative management regimes (with or without thinnings, different thinning intensities, several rotation lengths) combined with alternative harvesting methods (pulpwood, energy wood, or integrated, energy wood being delimbed stems or whole trees). We used data from 19 experimental stands, monitored for 20–30 years. For harvesting removals we considered both actual thinning removals and final-cutting removals with alternative timings that were based on the monitoring data. We assessed the profitability as a combination of the net present value of the birch generation and the bare land value of future generations of Norway spruce (Picea abies (L.) Karst.). The most profitable management was growing without thinnings until whole-tree final cutting at the stand age of 40–45 years with an advanced multi-tree harvesting method. In contrast, the standard method in whole-tree final cutting resulted in the lowest profitability, and an integrated method with the energy wood as delimbed stems was the best of the standard methods. Thinnings were unprofitable especially when aiming to produce energy wood, whereas aiming for pulpwood, light precommercial thinning was competitive. Commercial thinning at the traditional “pulpwood stage” had little effect on profitability. The best stand age for final cutting was 40–65 years – earlier for very dense stands and whole-tree energy wood harvesting with advanced method, later for precommercially thinned stands and pulpwood harvesting.

  • Niemistö, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Kampusranta 9 C, 60320 Seinäjoki, Finland E-mail: pentti.niemisto@luke.fi (email)
  • Kojola, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: soili.kojola@luke.fi
  • Ahtikoski, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Paavo Havaksentie 3, 90014 University of Oulu, Finland E-mail: anssi.ahtikoski@luke.fi
  • Laiho, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: raija.laiho@luke.fi
article id 1713, category Research article
Lars-Göran Stener, Lars Rytter, Gunnar Jansson. (2017). Effects of pruning on wood properties of planted silver birch in southern Sweden. Silva Fennica vol. 51 no. 2 article id 1713. https://doi.org/10.14214/sf.1713
Keywords: wood defects; discolouration; rot; ingrown bark
Highlights: Pruning silver birch trees increased the production of defect-free wood outside the knots; Most wood defects were found inside the knots; Pruned birch trees provide butt logs with higher value than unpruned trees.
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Pruning was performed at midsummer in two genetically homogenous and managed planted silver birch stands in southern Sweden – one aged 9 and one aged 10 years. Wood defects were analysed 10 years thereafter, using the five uppermost twigs of the stems up to a height of 30 dm. The number of trees examined at each site was around 70, of which half were pruned. The main findings were that: a) compared to unpruned trees, pruned trees produced more defect-free wood outside the knots; b) most wood defects were found inside the knots; and c) wood defects like rot and bark ingrowth were similar for pruned and unpruned trees, while discolouration was marginally higher for pruned trees inside knots but similar outside knots. Overall, the results confirm previous findings that pruned birch trees will provide butt logs with higher value than unpruned trees.

  • Stener, The Forestry Research Institute of Sweden, Ekebo 2250, 268 90 Svalöv, Sweden E-mail: lars-goran.stener@skogforsk.se (email)
  • Rytter, The Forestry Research Institute of Sweden, Ekebo 2250, 268 90 Svalöv, Sweden E-mail: lars.rytter@skogforsk.se
  • Jansson, The Forestry Research Institute of Sweden, Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: gunnar.jansson@skogforsk.se
article id 1599, category Research article
Andrew McEwan, Michal Brink, Raffaele Spinelli. (2017). Factors affecting the productivity and work quality of chain flail delimbing and debarking. Silva Fennica vol. 51 no. 2 article id 1599. https://doi.org/10.14214/sf.1599
Keywords: modeling; plantation; coppice; efficiency; pulpwood; processing
Highlights: Machine productivity averaged 59 m3 ub SMH–1, with a 19% incidence of delay time; Productivity increased 70% if tree volume increased from 0.1 to 0.4 m3 ub; Debarking quality was good for 58% of the trees, medium for 29% and poor for 13%; The more trees in a bunch and the higher BWBS, the lower debarking quality.
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Chain flail delimbing and debarking may improve value recovery from small tree harvests, without renouncing the benefits of multi-tree processing. The technology is mature and capable of excellent performance, which has been documented in many benchmark studies. This paper offers new insights into the relationship between the performance of chain flail delimbing and debarking and such factors as tree volume, load volume, tree form and bark-wood bond strength (BWBS). The study was conducted in Chile, during the commercial harvesting of a Eucalyptus globulus Labill. plantation. In an observational study, researchers collected production data from over 780 work cycles, and work quality data from over 1000 individual trees. The analysis of these data shows that productivity is affected primarily by load volume. Work quality is affected by BWBS and by the number of trees in a load. Work quality degrades with increasing BWBS and tree number, since more trees tend to shield each other. Tree form has no effect on either productivity or work quality. Regression and probability functions are provided, and can be used for predictive purposes when trying to optimize current operations or to prospect the introduction of chain flail technology to new work environments.

  • McEwan, Postgraduate Forest Programme, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag X20 Hatfield, Pretoria, 0028, South Africa E-mail: Andrew.McEwan@nmmu.ac.za
  • Brink, Postgraduate Forest Programme, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag X20 Hatfield, Pretoria, 0028, South Africa E-mail: michal@cmo.co.za
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (FI), Italy ORCID http://orcid.org/0000-0001-9545-1004 E-mail: spinelli@ivalsa.cnr.it (email)
article id 1694, category Research article
Katri Luostarinen, Katja Hakkarainen, Henri Kaksonen. (2017). Wood anatomy of seed and basal bud originated downy birches (Betula pubescens Ehrh.) grown at four different sites. Silva Fennica vol. 51 no. 1 article id 1694. https://doi.org/10.14214/sf.1694
Keywords: fibre; xylem; parenchyma; ray; vessel; sprout; wood structure
Highlights: Young xylem of sprouts did not clearly show more mature characteristics than that of seedlings; Marked differences in xylem structure could be observed between growing sites.
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In trees, xylem must fulfil three important tasks: conducting water to leaves, storing nutrients and water, and supporting the trunk. The origin of the trunk, i.e., seed or basal bud that forms sprouts, and the growth site may affect xylem anatomy, differences of which can affect successful growth of trees. Both seedlings and sprouts of downy birch (Betula pubescens Ehrh.) from four different growth sites with two different soil media, peat and mineral soil, were studied. The diameter of fibres and vessels and the thickness of the double fibre wall were measured, and the number of vessels, rays and axial parenchyma cells was counted. The fibre wall:lumen ratio, vessel percentage area and vessel size:number ratio were calculated. Xylem from sprouts showed only occasionally more mature characteristics than that of seedlings. The number of rays was similar at all four sites, but differences were observed in all other studied characteristics between sites, particularly if soil type was different. The vessel size and number correlated with the number of axial parenchyma cells in juvenile wood, which emphasises the importance of their connections with storage cells particularly at this stage of growth. Good water conductivity was connected with weaker wood, particularly in maturing wood.

  • Luostarinen, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: katri.luostarinen@uef.fi (email)
  • Hakkarainen, Natural Resources Institute of Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: katjahak@gmail.com
  • Kaksonen, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hkaksone@gmail.com
article id 1611, category Research article
Ilpo Ervasti. (2016). Wood fiber contents of different materials in the paper industry material chain expressed in roundwood equivalents (RWEs). Silva Fennica vol. 50 no. 4 article id 1611. https://doi.org/10.14214/sf.1611
Keywords: pulpwood; paper production; raw materials; roundwood equivalent (RWE); wood pulp; recycled fiber; recovered paper; material recycling
Highlights: The paper industry material recycling chain consists of different material streams; Consumed paper products form a huge fiber source for industry. However, a reliable measuring system should be developed to quantify these fiber volumes; Converting factors are introduced to quantify the wood fiber contents of different paper industry-related materials of the chain, namely, wood pulp, paper and recovered paper; By using these conversion factors it is possible to convert for example global recovered paper utilization volumes into wood fiber volumes expressed in roundwood equivalents (RWEs).
Abstract | Full text in HTML | Full text in PDF | Author Info

At present, there are no means for reliably comparing the wood fiber contents of different material streams within the paper industry material chain with each other. The aim of this article is to introduce conversion factors that make it possible to quantify the volume of wood expressed in roundwood equivalent (RWE) values for different paper industry-related materials in the material chain. These conversion factors apply to wood pulp, paper, and recovered paper. European data are used in quantifying the paper industry material streams and calculating the RWE conversion factors. The introduced conversion factors can be used to estimate RWE volumes at a global scale. With assumption that paper recycling did not occur and that paper production volume remained unchanged, an additional volume of 666 million m3 RWEs would be required globally per annum to produce 167 million tons of virgin wood pulp to replace 222 million tons of recovered paper utilized by the paper industry in 2010. This volume is approximately the same as 1.6 times the total removal of wood in Europe (EU27), or the total annual removal of wood in the USA, Canada, and Brazil combined.

  • Ervasti, Aalto University, Industrial Engineering and Management, Maarintie 8, 02150 Espoo, Finland E-mail: ilervasti@gmail.com (email)
article id 1461, category Research article
Ludmila Novitskaya, Nadezhda Nikolaeva, Natalia Galibina, Tatiana Tarelkina, Ludmila Semenova. (2016). The greatest density of parenchyma inclusions in Karelian birch wood occurs at confluences of phloem flows. Silva Fennica vol. 50 no. 3 article id 1461. https://doi.org/10.14214/sf.1461
Keywords: Betula pendula; patterned wood; parenchyma; branch attachments; forks; sucrose content
Highlights: Dark-colored inclusions creating the figured pattern in Karelian birch wood consist of storage parenchyma cells; Their greatest density is formed above branch attachments and below forks; In these zones, the sucrose content is elevated since photoassimilate flows of the trunk and branches merge into one pathway; A high level of sucrose enhances the differentiation of parenchyma cells.
Abstract | Full text in HTML | Full text in PDF | Author Info

The specific pattern of the wood of Karelian birch (Betula pendula Roth var. carelica (Merckl.) Hämet-Ahti), is created mainly by dark-coloured inclusions of parenchyma tissue. Our study revealed that the greatest density of parenchyma inclusions in Karelian birch wood is observed above branch attachments to the trunk and below forks. In the place of branch attachment, phloem flows of photoassimilates (sucrose) from the branch and along the trunk merge into one pathway, causing a rise in sucrose content in tissues there. In the area below the fork, sucrose flows from two (or more) trunk axes are combined. Many studies have demonstrated that elevated sucrose level is associated with the differentiation of parenchyma. We believe that where large phloem fluxes merge a high level of sucrose promotes mass differentiation of parenchyma cells instead of fibers and vessels. As a result, the density of the figured pattern in the wood increases. The obtained data have a practical value and can be used in developing recommendations for Karelian birch cultivation.

  • Novitskaya, Forest Research Institute, Karelian Research Center, Russian Academy of Sciences, Pushkinskaya str. 11, 185910, Petrozavodsk, Russia E-mail: ludnovits@rambler.ru (email)
  • Nikolaeva, Forest Research Institute, Karelian Research Center, Russian Academy of Sciences, Pushkinskaya str. 11, 185910, Petrozavodsk, Russia E-mail: kar-birch@mail.ru
  • Galibina, Forest Research Institute, Karelian Research Center, Russian Academy of Sciences, Pushkinskaya str. 11, 185910, Petrozavodsk, Russia E-mail: galibina@krc.karelia.ru
  • Tarelkina, Forest Research Institute, Karelian Research Center, Russian Academy of Sciences, Pushkinskaya str. 11, 185910, Petrozavodsk, Russia E-mail: karelina.t.v@gmail.com
  • Semenova, Forest Research Institute, Karelian Research Center, Russian Academy of Sciences, Pushkinskaya str. 11, 185910, Petrozavodsk, Russia E-mail: mi7enova@gmail.com
article id 1441, category Research article
Dorota Zawadzka, Stanisław Drozdowski, Grzegorz Zawadzki, Jerzy Zawadzki. (2016). The availability of cavity trees along an age gradient in fresh pine forests. Silva Fennica vol. 50 no. 3 article id 1441. https://doi.org/10.14214/sf.1441
Keywords: Pinus sylvestris; forest management; Poland; Augustów Forest; cavity-nesting birds; woodpeckers
Highlights: The density of cavity trees in pine-dominated, managed forests varied in relation to stand age and was highest in stands older than 130 years of age; Cavities excavated by woodpeckers dominated among all cavities; The number of trees with cavities appears insufficient to ensure the effective protection of bird diversity in managed stands of Augustów Forest.
Abstract | Full text in HTML | Full text in PDF | Author Info

Given their importance as a resource for many forest organisms, tree cavities were inventoried in the managed pine forests of north-east Poland, in relation to the: 70–100, 101–130 and >130 year age-classes within the clear-cutting system. The densities at which cavities were present was found to depend on forest age, given that stands 70–100 years old were characterised by an average density of 0.62 trees ha–1, while forests older than 130 years reported 3.28 trees ha–1. Stands aged 70–100 years differed from those aged 130+ in having just 0.27 trees ha–1 of cavity trees, as compared with 2.91 trees ha–1. The total volume of cavity trees in stands up to 100 years old was 0.37 m3 ha–1 on average, as compared with 5.42 m3 ha–1 in stands over 130 years old. The cavities created by woodpeckers constituted 76% of all of those found, and included 53% excavated by great spotted woodpeckers (Dendrocopos major L.) and 23% by black woodpeckers (Dryocopus martius L.) The proportion of cavities excavated by D. major was highest in the youngest age class of stands. There, cavities made by D. martius constituted only 8% of the total, as compared with 31% in the oldest stands. The abundance of cavity trees thus differed along an age gradient, though in any event the availability of cavity trees appears to be too limited to provide for the needs of hole-nesting birds. Forest managers must thus take more account than hitherto of the need to protect cavity trees.

  • Zawadzka, Institute of Forest Science, University of Łódź, Branch in Tomaszów Mazowiecki, Konstytucji 3 Maja 65/67, 97-200 Tomaszów Mazowiecki, Poland E-mail: dorota_zaw@wp.pl
  • Drozdowski, Department of Silviculture, Warsaw University of Life Sciences - SGGW, Nowoursynowska 159, 02-776 Warsaw, Poland E-mail: stanislaw_drozdowski@sggw.pl (email)
  • Zawadzki, Eagle Conservation Committee, Okółek 14, 16-506 Giby, Poland E-mail: grzesiekgfz@op.pl
  • Zawadzki, Eagle Conservation Committee, Okółek 14, 16-506 Giby, Poland E-mail: jerzy_zaw@wp.pl
article id 1521, category Research article
Kalle Karttunen, Juha Laitila, Tapio Ranta. (2016). First-thinning harvesting alternatives for industrial or energy purposes based on regional Scots pine stand simulations in Finland. Silva Fennica vol. 50 no. 2 article id 1521. https://doi.org/10.14214/sf.1521
Keywords: harvesting; energy wood; stand simulation; stumpage price; small-diameter wood
Highlights: Small-diameter delimbed wood from Scots pine stands delivered directly for energy use was the most cost-efficient option in terms of the total supply-chain cost in comparison with corresponding industrial use or a whole-tree supply chain for energy use; Forest-management and harvesting decisions influenced the removal of forest biomass and stumpage price as well as the total supply-chain costs for forest biomass; The greatest cost-reduction potential (10.0%, 4.00 € m–3) was achieved for the delimbed energy wood’s supply chain in the regional case of South Savo in eastern Finland.
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Combining research into forest management stand conditions and wood supply chain processes has been missing from earlier forestry studies. There is a clear need to develop more cost-efficient small-diameter wood production, harvesting and transportation methods from first thinning, which could be used for either industrial or energy wood purposes. This study considers the total cost for small-diameter wood originating from young Scots pine (Pinus sylvestris L.) dominated stands. Pine pulpwood is the most harvested and most used roundwood assortment, use of which is expected to rise following new pulp-mill investments in Finland. In addition, utilisation of small-diameter trees directly for energy purposes has been increasing steadily in recent years. The aim of the study was to determine the cost-reduction potential of alternative forest management options and supply chains for small diameter-wood in the regional case of South Savo in eastern Finland. The total costs of three distinct scenarios were studied on the basis of forest management, first-thinning harvesting methods, and transportation: 1) industrial wood, 2) delimbed energy wood, and 3) whole trees for energy purposes. The cost-reduction potential for energy-wood supply chains from first thinning was compared to the industrial supply chain. Small-diameter delimbed wood delivered straight for energy purposes was found to be the most cost-efficient as far as the total cost of the supply chain is concerned. More cost-efficient small-diameter wood processes can be found by linking forest stand simulations with supply chain analysis.

  • Karttunen, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland E-mail: kalle.karttunen@lut.fi
  • Laitila, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juha.laitila@luke.fi
  • Ranta, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland E-mail: tapio.ranta@lut.fi (email)
article id 1474, category Research article
Cedric A. Goussanou, Sabin Guendehou, Achille E. Assogbadjo, Maguette Kaire, Brice Sinsin, Aida Cuni-Sanchez. (2016). Specific and generic stem biomass and volume models of tree species in a West African tropical semi-deciduous forest. Silva Fennica vol. 50 no. 2 article id 1474. https://doi.org/10.14214/sf.1474
Keywords: carbon stock; allometric equations; non-destructive sampling; basic wood density
Highlights: Non-destructive sampling approach applied to derive ground truth observations and generate robust basic wood densities; Species-specific and generic allometric equations; Specific equations have better predictive capabilities than generic models.
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The quantification of the contribution of tropical forests to global carbon stocks and climate change mitigation requires availability of data and tools such as allometric equations. This study made available volume and biomass models for eighteen tree species in a semi-deciduous tropical forest in West Africa. Generic models were also developed for the forest ecosystem, and basic wood density determined for the tree species. Non-destructive sampling approach was carried out on five hundred and one sample trees to analyse stem volume and biomass. From the modelling of volume and biomass as functions of diameter at breast height (Dbh) and stem height, logarithmic models had better predictive capabilities. The model validation showed that in absence of data on height, models using Dbh only as variable was an alternative. The comparison of basic wood densities to data published in literature enabled to conclude that the non-destructive sampling was a good approach to determining reliable basic wood density. The comparative analysis of species-specific models in this study with selected generic models for tropical forests indicated low probability to identify effective generic models with good predictive ability for biomass. Given tree species richness of tropical forests, the study demonstrated the hypothesis that species-specific models are preferred to generic models, and concluded that further research should be oriented towards development of specific models to cover the full range of dominant tree species of African forests.

  • Goussanou, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin E-mail: cedricgoussanou@gmail.com (email)
  • Guendehou, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin; Benin Centre for Scientific and Technical Research, 03 BP 1665 Cotonou, Benin E-mail: sguendehou@yahoo.fr
  • Assogbadjo, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin E-mail: assogbadjo@yahoo.fr
  • Kaire, Centre Régional AGRHYMET, Département Formation et Recherche, BP 11011 Niamey, Niger E-mail: m.kaire@agrhymet.ne
  • Sinsin, Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey-Calavi, 01 BP 526 Cotonou, Benin E-mail: bsinsin@gmail.com
  • Cuni-Sanchez, University of Copenhagen, Center for Macroecology, Evolution and Climate, Nørregade 10, P.O. Box 2177, 1017 Copenhagen K, Denmark E-mail: aidacuni@hotmail.com
article id 1428, category Research article
Gernot Erber, Franz Holzleitner, Maximilian Kastner, Karl Stampfer. (2015). Effect of multi-tree handling and tree-size on harvester performance in small-diameter hardwood thinnings. Silva Fennica vol. 50 no. 1 article id 1428. https://doi.org/10.14214/sf.1428
Keywords: productivity; thinning; energy wood; motor-manual; accumulating harvester head; delimbing
Highlights: Harvesting with the accumulating energy wood head EF28 was studied under small tree dimension (8 dm3) in hardwood thinnings; Reasonable productivity was achieved; Maximum achieved cutting diameter in hornbeam stand was 23 cm and 15% lower than in softwood stands; Head has potential under such conditions.
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Early thinnings are laborious and costly. Thus forest companies are searching for cost and time efficient ways to carry out this task. The study’s purpose was to determine the productivity of the EF28 accumulating energy wood harvesting head in harvesting small-diameter hornbeam (Carpinus betulus L.) undergrowth trees and evaluate the effect of its multi-tree handling (MTH) capacity on time consumption. The harvester was a wheeled, three-axle Komatsu 911. A time study of 7.1 hours on 19 plots, with a total area of 0.76 ha was conducted. On average, the harvested tree volume was 8 dm³ and the stand density was 2666 trees/ha. The productivity was modelled with MTH conduction, mean diameter at breast height and the number of trees handled per cycle as independent variables. On average, MTH took 27% longer per cycle, increased extracted volume per cycle by 33% and consequently increased productivity with 5.0%. In 71.9% of the cycles more than one tree was handled and if so, dimensions were smaller than in single-tree handling (5.8 cm vs. 12.0 cm). Maximum felling diameter of 23 cm was about 15% smaller than in softwood (according to the manufacturer’s specifications) and the driver didn’t exploit the EF28’s theoretical potential in terms of trees handled per cycle. It can be concluded that the head could significantly improve productivity in small-diameter wood procurement.

  • Erber, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: gernot.erber@boku.ac.at (email)
  • Holzleitner, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: franz.holzleitner@boku.ac.at
  • Kastner, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: maximilian.kastner@boku.ac.at
  • Stampfer, Addresses University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Forest Engineering, Peter-Jordan Straße 82/3, A-1190 Vienna, Austria E-mail: karl.stampfer@boku.ac.at
article id 1393, category Research article
Werner Poschenrieder, Andreas Rais, Jan-Willem G. van de Kuilen, Hans Pretzsch. (2015). Modelling sawn timber volume and strength development at the individual tree level – essential model features by the example of Douglas fir. Silva Fennica vol. 50 no. 1 article id 1393. https://doi.org/10.14214/sf.1393
Keywords: sawing; wood quality modelling; stem structure; grading; sensitivity test; R statistical environment
Highlights: An individual tree timber growth and quality model toolbox was designed; It realistically predicts an increase of bending strength with planting density; Prediction was shown to be based on consideration of essential intrinsic variables; Height‑diameter‑allometry depending on planting density was effective; Consideration of cambial age and knot area ratio was crucial.
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We designed a streamlined timber growth and quality model that aims at the effect of stand management on the efficiency of wood resource use. Applying the R based module toolbox to experimental plots of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) we analysed essential model features for reflecting the influence of planting density on board strength. The current version realistically predicted a significant increase of centre board bending strength at tree age 40 with initial stand density. Model performance gained clear advantage from a) parameterisation of height to diameter allometry as dependent on planting density b) consideration of cambial age and cross‑sectional knot area in board strength computation. Crown shape was less decisive. The model produced a significant effect of planting density even after a whole rotation period of 70 years as well as a realistic spectrum of board bending strength.

  • Poschenrieder, Technische Universität München, Chair of Forest Growth and Yield Science, Hans Carl von Carlowitz Platz 2, 85354 Freising, Germany ORCID http://orcid.org/0000-0002-9028-8583 E-mail: Werner.Poschenrieder@lrz.tum.de (email)
  • Rais, Technische Universität München, Chair of Forest Growth and Yield Science, Hans Carl von Carlowitz Platz 2, 85354 Freising, Germany; Technische Universität München, Holzforschung München, Winzererstrasse 45, 80797 Munich, Germany E-mail: Andreas.Rais@hfm.tum.de
  • van de Kuilen, Technische Universität München, Holzforschung München, Winzererstrasse 45, 80797 Munich, Germany E-mail: vandekuilen@hfm.tum.de
  • Pretzsch, Technische Universität München, Chair of Forest Growth and Yield Science, Hans Carl von Carlowitz Platz 2, 85354 Freising, Germany E-mail: Hans.Pretzsch@lrz.tum.de
article id 1341, category Research article
Přemysl Humplík, Petr Čermák, Tomáš Žid. (2016). Electrical impedance tomography for decay diagnostics of Norway spruce (Picea abies): possibilities and opportunities. Silva Fennica vol. 50 no. 1 article id 1341. https://doi.org/10.14214/sf.1341
Keywords: sapwood; heartwood; tomogram; decay proportion; impedance dataset
Highlights: Statistical parameters of EIT datasets with values of electrical resistance of heartwood are possible to employ in refining heartwood rot diagnostics; Sapwood proportion is decreasing as the proportion of decay on the radial cut expands; Using EIT datasets and sapwood proportion, trees with rot can be split into two groups as per proportion of decay: [< 35%] and [> 35%].
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The paper aimed at testing the potential of refining tree rot diagnostics carried out by means of electrical impedance tomography (EIT). Examined was the use of EIT datasets with electrical resistance values and sapwood proportion determined on the basis of tomograms. Making use of datasets with resistance values in EIT rot diagnostics is not a default method, although datasets stay unaffected by a fixed colour scale and subsequent subjective evaluation unlike tomograms. Tomography measurement was carried out for 27 individuals of Norway spruce (Picea abies [L.] Karst.) in two stands north-east of Brno, Czech Republic. Once felled down, radial cut-outs were sampled at the measurement site and used for localising rot and determining the extent of the area of decay. The results were subsequently compared with tomograms. EIT datasets containing values of electrical resistance found by measuring were statistically processed and compared with the extent of rot area identified within the cuts. Sapwood proportion values were also detected using the tomograms. The baseline assumption that sapwood proportion decreases as the rot area in the radial cut expands was confirmed. In trees with rot percentage to 35% approximately, sapwood proportion was exceeding 30% except one tree. In trees with rot percentage exceeding 35%, sapwood proportion was below 30%. On the basis of interpreted datasets, the trees can be split into three characteristic groups that correspond to the occurrence, extent and nature of the rot.

  • Humplík, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 1665/3, 613 00 Brno, Czech Republic E-mail: premysl.humplik@mendelu.cz (email)
  • Čermák, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 1665/3, 613 00 Brno, Czech Republic E-mail: petr.cermak@mendelu.cz
  • Žid, Mendel University in Brno, Faculty of Forestry and Wood Technology, Zemědělská 1665/3, 613 00 Brno, Czech Republic E-mail: tomas.zid@mendelu.cz
article id 1394, category Research article
Sari Karvinen, Tuomas Nummelin. (2015). Finnish wood harvesting contractors’ risks in Russia. Silva Fennica vol. 49 no. 5 article id 1394. https://doi.org/10.14214/sf.1394
Keywords: Russia; contracting; wood harvesting; risk analysis
Highlights: Disagreements on wood measurement and payment delays were the most important economic risks; Dependency on a few clients created risk for unfavourable agreements and work interruptions; Fires in site huts caused the risk of personal injury; Inadequate professional skills were serious economic and work interruption risks; Unhealthy competition, the functioning of the authorities, and infrastructure were important external risk factors.
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Finnish wood harvesting contractors have been working in Russia since the 1990s and new entrepreneurs are still interested in starting operations there, even though Russia is not an easy business environment. This study identifies the most significant risks in contracting in Russia. Risks were identified through expert evaluation and a risk analysis was conducted by using a risk matrix. Possible preventative measures were assessed for the identified risks. Some risks were found to be common in Russia and Finland, for example a limited number of clients, dependency on a few clients, and weak negotiating positions. A stable amount of work, i.e. the availability of stands for harvesting, was also a challenge on the both sides of border. Typical problems in Russia were breaches of contract, especially disagreements on wood measurement and payment delays, potentially causing serious economic losses. Specific to Russia were problems related to machine service and spare parts, as well as security issues. The professional skills of machine operators, as well as changing work motivation were risks in Russia. Cultural differences lead to more challenging supervision and management of staff. Among the external factors, the most challenging in Russia were unhealthy competition in the marketplace and non-transparent and the unpredictable procedures of the authorities. In Russia problems caused by seasonality are amplified by the sparse road network and longer downtime. The revealed specific features of the Russian business environment can help Finnish wood harvesting companies to plan a risk management process for operations in Russia.

  • Karvinen, Natural Resources Institute Finland (Luke), Economics and society, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: sari.karvinen@luke.fi (email)
  • Nummelin, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: tuomas.nummelin@luke.fi
article id 1382, category Research article
Juha Laitila, Johanna Routa. (2015). Performance of a small and a medium sized professional chippers and the impact of storage time on Scots pine (Pinus sylvestris) stem wood chips characteristics. Silva Fennica vol. 49 no. 5 article id 1382. https://doi.org/10.14214/sf.1382
Keywords: chipping; productivity; quality; fuel; particle size; storage time; sieve; stem wood
Highlights: The storage time of pulpwood had no significant effect on particle size distribution in any chip size classes; The study confirms the knowledge that chipping time consumption is inversely proportional to engine power and grapple load size in feeding; The use of an narrower 80 mm × 80 mm sieve on Scots pine material does not seem to offer any benefit compared to a 100 mm × 100 mm sieve from the perspective of chip quality.
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The primary aim of this study was to clarify the chipping productivity and fuel consumption of tractor-powered and truck-mounted drum chippers when chipping pine pulpwood at a terminal. The secondary aim was to evaluate the impact of wood storage time on the chemical and physical technical specifications of wood chips by chipping pulpwood from eight different storage time groups, using Scots pine (Pinus sylvestris) pulpwood stems logged between 2 and 21 months previously at the terminal with the above-mentioned chippers. Thirdly, the impact of sieve mesh size on the particle size distribution of wood chips from different age groups was compared by using an 80 mm × 80 mm sieve for a tractor-powered chipper and a 100 mm × 100 mm sieve for a truck-mounted chipper. With both chippers, the chipping productivity grew as a function of grapple load weight. The average chipping productivity of the tractor-powered chipper unit was 19 508 kg (dry mass) per effective hour (E0h), and for the truck-mounted chipper the average productivity was 31 184 kg E0h–1. The tractor-powered drum chipper’s fuel consumption was 3.1 litres and for the truck-mounted chipper 3.3 litres per chipped 1000 kg (dry mass). The amount of extractives or volatiles did not demonstrate any statistically significant differences between storage time groups. The particle size distributions with both chippers were quite uniform, and the storage time of pulpwood did not have a significant effect on the particle size distribution in any chip size classes. One reason for this might be that the basic density of chipped wood was homogenous and there was no statistical difference between different storage times. The use of new sharp knives is likely to have affected chip quality, as witnessed by the absence of oversized particles and the moderate presence of fines. The use of narrower 80 mm × 80 mm sieves on Scots pine material does not seem to offer any benefit compared to 100 mm × 100 mm from the chip quality point of view.

  • Laitila, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juha.laitila@luke.fi (email)
  • Routa, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: johanna.routa@luke.fi
article id 1377, category Research article
Raul Fernandez-Lacruz, Fulvio Di Fulvio, Dimitris Athanassiadis, Dan Bergström, Tomas Nordfjell. (2015). Distribution, characteristics and potential of biomass-dense thinning forests in Sweden. Silva Fennica vol. 49 no. 5 article id 1377. https://doi.org/10.14214/sf.1377
Keywords: bioenergy; GIS; wood fuel; early thinning; small-tree harvesting; biomass potential; biomaterial
Highlights: Biomass-dense thinning forests (BDTF) cover 2.1–9.8 M ha in Sweden, which represents 9–44% of the country’s productive forest land area, depending on the constraints applied; 65% of BDTF area is found in northern Sweden; Analyses revealed a yearly harvesting potential of at least 4.3 M OD t of undelimbed whole trees (3.0 M OD t of delimbed stemwood including tops).
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Understanding the characteristics of unutilized biomass resources, such as small-diameter trees from biomass-dense thinning forests (BDTF) (non-commercially-thinned forests), can provide important information for developing a bio-based economy. The aim of this study was to describe the areal distribution, characteristics (biomass of growing stock, tree height, etc.) and harvesting potential of BDTF in Sweden. A national forest inventory plot dataset was imported into a geographical information system and plots containing BDTF were selected by applying increasingly stringent constraints. Results show that, depending on the constraints applied, BDTF covers 9–44% (2.1–9.8 M ha) of the productive forest land area, and contains 7–34% of the total growing stock (119–564 M OD t), with an average biomass density of 57 OD t ha–1. Of the total BDTF area, 65% is located in northern Sweden and 2% corresponds to set-aside farmlands. Comparisons with a study from 2008 indicate that BDTF area has increased by at least 4% (about 102 000 ha), in line with general trends for Sweden and Europe. Analyses revealed that the technical harvesting potential of delimbed stemwood (over bark, including tops) from BDTF ranges from 3.0 to 6.1 M OD t yr–1 (7.5 to 15.1 M m3 yr–1), while the potential of whole-tree harvesting ranges from 4.3 to 8.7 M OD t yr–1 (10.2 to 20.6 M m3 yr–1) depending on the scenario considered. However, further technological developments of the harvest and supply systems are needed to utilize the full potential of BDTF.

  • Fernandez-Lacruz, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID http://orcid.org/0000-0001-9284-8911 E-mail: raul.fernandez@slu.se (email)
  • Di Fulvio, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden; International Institute for Applied Systems Analysis (IIASA), Ecosystems Services and Management Program (ESM), Schlossplatz 1, A-2361 Laxenburg, Austria E-mail: Fulvio.di.Fulvio@slu.se
  • Athanassiadis, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: Dimitris.Athanassiadis@slu.se
  • Bergström, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: Dan.Bergstrom@slu.se
  • Nordfjell, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden E-mail: Tomas.Nordfjell@slu.se
article id 1342, category Research article
Blas Mola-Yudego, Gianni Picchi, Dominik Röser, Raffaele Spinelli. (2015). Assessing chipper productivity and operator effects in forest biomass operations. Silva Fennica vol. 49 no. 5 article id 1342. https://doi.org/10.14214/sf.1342
Keywords: mixed models; efficiency; comminution; operator effect; raw material supply; wood chippers
Highlights: A model is constructed to assess the productivity in chipping of wood biomass at roadside; The data includes 172 trials and 67 operators in Italy; The operator effect was included in a mixed model approach; The R2 were 0.76 (fixed part) and 0.88 (incl. operator effects).
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The present research focuses on the productivity of energy wood chipping operations at several sites in Italy. The aim was to assess the productivity and specifically the effect attributed to the operator in the chipping of wood biomass. The research included 172 trials involving 67 operators across the country that were analysed using a mixed model approach, in order to assess productivity, and to isolate the operator effect from other potential variables. The model was constructed using different predictors aiming to explain the variability due to the machines and the raw-materials. The final model included the average piece weight of raw material chipped as well as the power of the machine. The coefficients of determination (R2) were 0.76 for the fixed part of the model, and 0.88 when the effects due to the operators were included. The operators’ performance compared to their peers was established, and it was compared to a subjective classification based on the operator’s previous experience. The results of this study can help to the planning and logistics of raw material supply for bioenergy, as well as to a more effective training of future forest operators.

  • Mola-Yudego, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland; NIBIO Norwegian Institute of Bioeconomy Research, P.O. Box 115, 1431 Ås, Norway ORCID http://orcid.org/0000-0003-0286-0170 E-mail: blas.mola@uef.fi (email)
  • Picchi, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy E-mail: picchi@ivalsa.cnr.it
  • Röser, Forest Feedstocks Group, FPInnovations, Vancouver, British Columbia, Canada E-mail: dominik.roser@fpinnovations.ca
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy E-mail: spinelli@ivalsa.cnr.it
article id 1391, category Research article
Roberts Matisons, Jānis Jansons, Juris Katrevičs, Āris Jansons. (2015). Relation of tree-ring width and earlywood vessel size of alien Quercus rubra L. with climatic factors in Latvia. Silva Fennica vol. 49 no. 4 article id 1391. https://doi.org/10.14214/sf.1391
Keywords: dendroclimatology; climate-growth relationships; introduced species; earlywood vessel lumen area; wood anatomy; shifting sensitivity
Highlights: Climate-growth relationships of red oak from three sites in Latvia were studied; Tree-ring width was mainly affected by temperature and precipitation in late summer; Vessel size was correlated with temperature parameters in autumn–spring; Sets of climatic factors significant for growth of red oak differed between sites; Changes in climate-growth relationships occurred during 20th century.
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The effect of climatic factors on wood anatomy of the alien red oak (Quercus rubra L.) growing in three experimental plantations in Latvia was assessed by classical dendrochronological techniques. Two tree-ring proxies – tree-ring width (TRW) and mean area of earlywood vessel lumen (VLA) – were studied on 33 trees. Annual variation of TRW amongst trees was similar (mean r = 0.46), but there was more individuality in VLA (mean r = 0.26); nevertheless, chronologies of both proxies had rather synchronous variation amongst the sites. Annual variation of TRW was affected by factors related to water deficit in late summer, as suggested by the negative effect of temperature and positive effect of precipitation that have intensified during the 20th century, likely due to warming. Although weather conditions during the dormant period did not directly affect TRW, temperature during the autumn-spring period has been the main climatic determinant of VLA likely via influence on overwintering and hence vigour of tree. This suggests that conductive properties of wood and hence the susceptibility to water deficit have been affected by weather conditions before the formation of tree rings. During the 20th century, sensitivity of VLA has shifted from temperature in winter to temperature in autumn likely due to climate change. Still, the positive effect of these factors suggests that warming of climate would increase VLA and hence the risk of embolism and xylem disfunction. Therefore, the importance of availability of water for growth of red oak in Latvia is increasing.

  • Matisons, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv (email)
  • Jansons, Latvian Forest Competence Centre, Dzērbenes str. 27, Riga, Latvia, LV 1006 E-mail: janis.jansons@silava.lv
  • Katrevičs, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: juris.katrevics@silava.lv
  • Jansons, LSFRI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
article id 1337, category Research article
Leszek Bujoczek, Małgorzata Bujoczek, Jan Banaś, Stanisław Zięba. (2015). Spruce regeneration on woody microsites in a subalpine forest in the western Carpathians. Silva Fennica vol. 49 no. 3 article id 1337. https://doi.org/10.14214/sf.1337
Keywords: Picea abies; coarse woody debris; stumps; decomposition; regression model; fallen deadwood
Highlights: The occurrence probability of Picea abies seedlings on fallen deadwood was found to increase with diameter and decay stage of deadwood and with the volume of living trees, and to decrease with the density of living trees, sapling density, and land slope. It was also higher on stumps with greater diameter and in plots with higher sapling density, but decreased with increasing stump height.
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The density of Picea abies [L.] Karst. regeneration on different microsites, the quantity and quality of woody microsites, and seedling occurrence probability on stumps and fallen deadwood were studied in a subalpine forest that has been under protection for approximately 30–40 years (Gorce Mountains in the western Carpathians). Thirty percent of seedlings and 29% of saplings grew on stumps and fallen deadwood, while the remaining regeneration occurred on soil surface and mounds created by uprooted trees. The occurrence probability of Picea seedlings on fallen deadwood increased with deadwood diameter and decay stage and with the volume of living trees, and decreased with increased density of living trees, sapling density, and land slope. Furthermore, seedlings were more likely to grow on stumps with a greater diameter and in plots with higher sapling density, but less likely to grow on higher stumps. Stumps and fallen deadwood covered about 4% of the forest floor, but the material that is most important for promoting regeneration (strongly decomposed logs and those of a diameter exceeding 30 cm) took up only about 22 m2 ha-1. We have concluded that in a subalpine forest that has been protected for 30–40 years regeneration processes take place mostly on soil surface and stumps. The role of fallen deadwood increases over time as a greater number of suitable logs (in terms of size and decay stage) become available.

  • Bujoczek, University of Agriculture in Krakow, E-mail: lbujoczek@gmail.com (email)
  • Bujoczek, University of Agriculture in Krakow, E-mail: bujoczek.m@gmail.com
  • Banaś, University of Agriculture in Krakow, E-mail: rlbanas@cyf-kr.edu.pl
  • Zięba, University of Agriculture in Krakow, E-mail: rlzieba@cyf-kr.edu.pl
article id 1293, category Research article
Jukka Malinen, Mika Haring, Harri Kilpeläinen, Erkki Verkasalo. (2015). Comparison of alternative roundwood pricing systems – a simulation approach. Silva Fennica vol. 49 no. 3 article id 1293. https://doi.org/10.14214/sf.1293
Keywords: simulation; pricing; roundwood
Highlights: A discrete event simulation model was developed for studying roundwood pricing systems; For a single buyer, pricing based on residual value appraisal produced (RVA) 4.87 per cent higher wood paying capability and 3.70 per cent higher stumpage price than pricing based on average unit prices; As the number of buyers using RVA increases, the competition increased and the advantage decreased.
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In a closed market, roundwood buyers pricing system affect the roundwood flow from the stands to different roundwood users. If a buyer is capable to discriminate higher value stands from low quality stands better than its competitors, the buyer should be able to buy better raw material. In the study, a discrete event simulation was used to examine the effect of residual value appraisal (RVA) -based pricing of roundwood by log dimensions and grades compared to the traditional pricing based on average unit prices (UP) of roundwood assortments on roundwood flow. The core of the simulation model was the data containing 51 pine dominated stands from southern Finland. Sample trees were theoretically bucked by the bucking simulator in order to estimate the volumes, dimensions and grades of the logs and roundwood assortments. The simulation model of roundwood markets included four roundwood buyers, two corporations and two saw milling enterprises. The main finding of the study was that the buyers who use RVA gains an advantage and receives better quality compared to buyers who use UP. As the number of buyers using RVA increases, the competition increased and the advantage decreased.

  • Malinen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jukka.malinen@uef.fi (email)
  • Haring, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: mika.haring@gmail.com
  • Kilpeläinen, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: harri.kilpelainen@luke.fi
  • Verkasalo, Natural Resources Institute Finland (Luke), Bio-based business and industry, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: erkki.verkasalo@luke.fi
article id 1219, category Research article
Thomas P. Sullivan, Druscilla S. Sullivan. (2014). Diversifying clearcuts with green-tree retention and woody debris structures: conservation of mammals across forest ecological zones. Silva Fennica vol. 48 no. 5 article id 1219. https://doi.org/10.14214/sf.1219
Keywords: clearcutting; green-tree retention; small mammals; coniferous forests; ecological zones; Myodes gapperi; population dynamics; red-backed voles; woody debris structures
Highlights: Species diversity of small mammals increased with structural complexity left on clearcut sites; Productivity of red-backed vole populations was higher in sites with green-tree retention (GTR) and windrows of woody debris; GTR and windrows may provide additive effect for providing habitat to conserve mammals on clearcuts.
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We tested the hypotheses (H) that on newly clearcut-harvested sites, (H1) abundance and species diversity of the forest-floor small mammal community, and (H2) abundance, reproduction, and recruitment of red-backed voles (Myodes gapperi Vigors), would increase with higher levels of structural retention via green-tree retention (GTR) and woody debris (dispersed and constructed into windrows). Study areas were located in three forest ecological zones in southern British Columbia, Canada. For H1, mean total abundance did generally increase with the gradient of retained habitat structure. Mean species richness and diversity were similar among treatment sites but did show an increasing gradient with structural compexity. For H2, mean abundance, reproduction, and recruitment of M. gapperi were higher in GTR and windrow sites than those without retained structures. There was a positive relationship between mean abundance of M. gapperi and total volume of woody debris across treatments. This study is the first investigation of the responses of forest-floor small mammals to an increasing gradient of retained habitat structure via GTR and woody debris on clearcuts. Our assessment of a combination of these two interventions suggested a potentially strong additive effect that could be cautiously extrapolated across three forest ecological zones. With the advent of low levels of GTR on clearcuts, woody debris structures should help provide some habitat to conserve forest mammals on harvest openings.
  • Sullivan, Department of Forest and Conservation Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: tom.sullivan@ubc.ca (email)
  • Sullivan, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: dru.sullivan@appliedmammal.com
article id 1124, category Research article
Āris Jansons, Mārtiņš Zeps, Juris Rieksts-Riekstiņš, Roberts Matisons, Oskars Krišāns. (2014). Height increment of hybrid aspen Populus tremuloides x P. tremula as a function of weather conditions in central part of Latvia. Silva Fennica vol. 48 no. 5 article id 1124. https://doi.org/10.14214/sf.1124
Keywords: height growth; energy wood; tree growth; temperature; intra-annual dynamics; plantation silviculture
Highlights: Intra-annual height growth of hybrid aspen was monitored; Clones with early leaf flushing dates showed faster height growth; Height growth was generally controlled by temperature; Fast-growing hybrids were more robust to weather conditions than slow-growing ones; Potential evapotranspiration (moisture regime) negatively affected height growth of clones with delayed phenology.
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Height growth of young hybrid aspen (Populus tremula L. × P. tremuloides Michx.) was studied in relation to weather conditions. Height of clones with different leaf flushing phenology (early, intermediate and late) was monitored during the growing periods of 2010 and 2011 in a plantation established on former agricultural land. Mean daily height increment (HI) was calculated. Multiple linear regression was used to determine which weather factors (variables) had significant effect on HI. Mean seasonal height growth (mean seasonal HI) between clones (groups) was compared by ANOVA. In both years, HI was significantly higher for clones with early and intermediate leaf flushing compared to clones with late leaf flushing. The effect of weather factors also differed between clones according to their leaf flushing phenology; it was the weakest for HI of clones with early leaf flushing compared to clones with intermediate and late leaf flushing. Mean temperature was the main factor, which positively affected HI of all clones, suggesting that warmer climate might be beneficial for height growth of young hybrid aspen in Latvia. Nevertheless, significant negative relationship between HI and potential evapotranspiration (PET) was observed for clones with delayed leaf flushing, suggesting negative effect of increasing variability of precipitation on growth. Thus, the differences in height growth intensity might be related to growth sensitivity to weather conditions. On the other hand, such differences in height growth between clones might be caused by competition (i.e. with herbs), as trees with early leaf flushing might conquer more resources and become more robust against the environmental fluctuation.
  • Jansons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
  • Zeps, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: martins.zeps@silava.lv
  • Rieksts-Riekstiņš, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: Juris.Riekstins@silava.lv
  • Matisons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv (email)
  • Krišāns, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: oskars.krisans@silava.lv
article id 1107, category Research article
Arvo Tullus, Arne Sellin, Priit Kupper, Reimo Lutter, Linnar Pärn, Anna K. Jasinska, Meeli Alber, Maarja Kukk, Tea Tullus, Hardi Tullus, Krista Lõhmus, Anu Sõber. (2014). Increasing air humidity – a climate trend predicted for northern latitudes – alters the chemical composition of stemwood in silver birch and hybrid aspen. Silva Fennica vol. 48 no. 4 article id 1107. https://doi.org/10.14214/sf.1107
Keywords: climate change; Betula; Populus; macronutrients; atmospheric humidity; wood characteristics; structural carbohydrates
Highlights: Hybrid aspen and silver birch trees grew more slowly under increased air humidity conditions and had higher concentrations of N and P and a lower K to N ratio in stemwood; Minor species-specific changes were detected in stemwood concentrations of cellulose and hemicellulose; Density, calorific value and concentrations of lignin and ash in stemwood were not affected by elevated humidity.
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We studied the physicochemical properties of stemwood in saplings of silver birch (Betula pendula Roth) and hybrid aspen (Populus tremula L. × P. tremuloides Michx.), grown for four years under artificially elevated relative air humidity (on average by 7%) in field conditions, using the Free Air Humidity Manipulation (FAHM) research facility in Estonia. Altogether 91 sample trees from three experimental plots with manipulated air humidity and from three control plots were cut in the dormant season and sampled for the analysis of cellulose, hemicellulose, acid detergent lignin, macronutrients (N, P, K), ash content, density, and calorific value of wood. The analysed trees grew significantly more slowly under elevated humidity conditions, with a more pronounced effect on aspens. Significantly higher concentrations of N and P were observed in the stemwood of both aspens and birches grown under elevated humidity. This could be the result of a change in the content of living parenchyma cells and/or enhanced retranslocation of nutrients into wood parenchyma. Additionally, humidification resulted in a significantly higher concentration of cellulose and a lower concentration of hemicellulose in aspen stemwood, and in significantly lower concentrations of cellulose and K in birch stemwood. Elevated humidity did not affect lignin concentration, ash content, basic density and calorific value of stemwood. Results from the FAHM experiment suggest that the increasing air humidity accompanying global warming at northern latitudes will affect the growth and functioning of deciduous trees and forests, with obvious consequences also for forest management and industry.
  • Tullus, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: arvo.tullus@ut.ee (email)
  • Sellin, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: arne.sellin@ut.ee
  • Kupper, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: priit.kupper@ut.ee
  • Lutter, Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51014, Estonia E-mail: reimo.lutter@emu.ee
  • Pärn, Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51014, Estonia E-mail: linnar.parn@emu.ee
  • Jasinska, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia & Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland E-mail: jasiak9@wp.pl
  • Alber, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: meeli.alber@ut.ee
  • Kukk, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: maarja.kukk@ut.ee
  • Tullus, Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51014, Estonia E-mail: tea.tullus@emu.ee
  • Tullus, Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu 51014, Estonia E-mail: hardi.tullus@emu.ee
  • Lõhmus, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: krista.lohmus@ut.ee
  • Sõber, Department of Botany, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Lai 40, Tartu 51005, Estonia E-mail: anu.sober@ut.ee
article id 1054, category Research article
Karin Kolis, Juhana Hiironen, Esa Ärölä, Arvo Vitikainen. (2014). Effects of sale-specific factors on stumpage prices in Finland. Silva Fennica vol. 48 no. 3 article id 1054. https://doi.org/10.14214/sf.1054
Keywords: pulpwood; timber trade; standing timber sales; hedonic price; sawlogs; non-industrial forest owners
Highlights: Data on 4824 individual sales were used to estimate which factors affect stumpage prices; The time of sale, seasonal harvest restrictions, the location and the assortment affected prices; Larger total volumes and shorter forest haulage distances raised unit prices; A higher percentage of the assortment and percentage of sawlogs within the sale corresponded to higher prices.
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Buyers of standing timber take not only the market situation but also the harvest costs into consideration when making purchase offers. In Finland, 85% of all timber is sold as standing timber, but there is little information for forest owners and third parties regarding how differences in harvest costs are reflected in the stumpage prices. This article analyses the relationship between sale-specific factors and stumpage prices in Finland. Data on 4824 standing timber sales between 2008 and 2012 were gathered from five local Forest Management Associations. Regression analyses were run on the stumpage prices (euros m–3) paid for sawlogs and pulpwood. Seasonal harvest restrictions, the volume of the sale and the timber assortment influenced stumpage prices, as did the presence of forest damages. Prices also differed over time and between locations. Furthermore, the forest haulage distance was statistically significant for pulpwood. The results suggest that the size of the individual sales and the composition of assortments affect the income owners earn from their forest. The results can be used to estimate stumpage prices and the monetary impacts on forest owners of procedures such as forest road network planning and land consolidation, as well as for valuation of forests.
  • Kolis, Aalto University, Department of Real Estate, Planning and Geoinformatics, P.O. Box 12200, FI-00076 Aalto, Finland E-mail: karin.kolis@aalto.fi (email)
  • Hiironen, Aalto University, Department of Real Estate, Planning and Geoinformatics, P.O. Box 12200, FI-00076 Aalto, Finland E-mail: juhana.hiironen@aalto.fi
  • Ärölä, National Land Survey of Finland, Production Support Services, P.O. Box 84, FI-00521 Helsinki, Finland E-mail: esa.arola@nls.fi
  • Vitikainen, Aalto University, Department of Real Estate, Planning and Geoinformatics, P.O. Box 12200, FI-00076 Aalto, Finland E-mail: arvo.vitikainen@aalto.fi
article id 980, category Research article
Atte Komonen, Panu Halme, Mari Jäntti, Tuuli Koskela, Janne S. Kotiaho, Tero Toivanen. (2014). Created substrates do not fully mimic natural substrates in restoration: the occurrence of polypores on spruce logs. Silva Fennica vol. 48 no. 1 article id 980. https://doi.org/10.14214/sf.980
Keywords: Norway spruce; boreal forest; ecological restoration; dead wood; protected area management; substrate quality; wood-decaying fungi
Highlights: Polypore communities were more homogeneous among created than among natural logs; The old-growth forest indicator Phellinus ferrugineofuscus occurred frequently on natural logs, but occupied only a few created logs; Results show that created logs do not fully mimic natural logs.
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Many protected areas have been under intensive forest management prior to protection and thus lack natural ecosystem structures and dynamics. Dead wood is a key structure in forests harboring hundreds of threatened species. We investigated the ecological success of dead wood creation as a boreal forest restoration measure. We analysed whether the polypore communities of chain-saw felled and girdled (subsequently fallen) Norway spruce (Picea abies (L.) H. Karst.) logs differ from naturally formed spruce logs of similar decay stage and size. The study was conducted in Leivonmäki National Park in central Finland 8 years after the restoration measures. The average number of polypore species was highest on the chain-saw felled logs and most of the common polypore species were most frequent on this substrate. However, among the natural logs, number of species increased more steeply with increasing number of logs, suggesting greater variation in community composition on this substrate. The old-growth forest indicator Phellinus ferrugineofuscus occurred frequently on natural logs, occupied a few girdled logs but was absent from chain-saw felled logs. Our results show that from the polypore perspective created logs do not fully mimic natural logs, suggesting that creating substrates for species may pose a challenge for restoration.
  • Komonen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland E-mail: atte.komonen@jyu.fi (email)
  • Halme, Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland E-mail: panu.halme@jyu.fi
  • Jäntti, Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland E-mail: mari.j.jantti@student.jyu.fi
  • Koskela, Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland E-mail: tuuli.e.koskela@student.jyu.fi
  • Kotiaho, Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland E-mail: janne.kotiaho@jyu.fi
  • Toivanen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014, University of Jyväskylä, Finland; Current: Birdlife Finland, Annankatu 29 A 16, FI-00100 Helsinki, Finland E-mail: tero.toivanen@birdlife.fi
article id 962, category Research article
Paul A. Klockow, Anthony W. D'Amato, John B. Bradford, Shawn Fraver. (2014). Nutrient concentrations in coarse and fine woody debris of Populus tremuloides Michx.-dominated forests, northern Minnesota, USA. Silva Fennica vol. 48 no. 1 article id 962. https://doi.org/10.14214/sf.962
Keywords: coarse woody debris; fine woody debris; Populus tremuloides; nutrient concentrations; bioenergy feedstock harvesting; Great Lakes
Highlights: We examine effects of size, species, and decay on woody debris nutrient concentrations; Results indicate wide variation in nutrient concentrations across the factors examined; Fine woody debris nutrient concentrations were greater than in coarse woody debris; Coarse woody debris nutrient concentrations generally increased as decay progressed; Results suggest high fine woody debris stocks can represent an important nutrient source.
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Contemporary forest harvesting practices, specifically harvesting woody biomass as a source of bioenergy feedstock, may remove more woody debris from a site than conventional harvesting. Woody debris, particularly smaller diameter woody debris, plays a key role in maintaining ecosystem nutrient stores following disturbance. Understanding nutrient concentrations within woody debris is necessary for assessing the long-term nutrient balance consequences of altered woody debris retention, particularly in forests slated for use as bioenergy feedstocks. Nutrient concentrations in downed woody debris of various sizes, decay classes, and species were characterized within one such forest type, Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Nutrient concentrations differed significantly between size and decay classes and generally increased as decay progressed. Fine woody debris (≤ 7.5 cm diameter) had higher nutrient concentrations than coarse woody debris (> 7.5 cm diameter) for all nutrients examined except Na and Mn, and nutrient concentrations varied among species. Concentrations of N, Mn, Al, Fe, and Zn in coarse woody debris increased between one and three orders of magnitude, while K decreased by an order of magnitude with progressing decay. The variations in nutrient concentrations observed here underscore the complexity of woody debris nutrient stores in forested ecosystems and suggest that retaining fine woody debris at harvest may provide a potentially important source of nutrients following intensive removals of bioenergy feedstocks.
  • Klockow, Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, USA E-mail: klock039@umn.edu (email)
  • D'Amato, Department of Forest Resources, University of Minnesota, St. Paul, MN 55108, USA E-mail: damato@umn.edu
  • Bradford, US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ 86001, USA E-mail: jbradford@usgs.gov
  • Fraver, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: shawn.fraver@maine.edu
article id 1047, category Research article
Kalle Karttunen, Lauri Lättilä, Olli-Jussi Korpinen, Tapio Ranta. (2013). Cost-efficiency of intermodal container supply chain for forest chips. Silva Fennica vol. 47 no. 4 article id 1047. https://doi.org/10.14214/sf.1047
Keywords: trucks; railways; wood fuels; transportation systems
Highlights: The combined availability and simulation study method obtains more realistic results for use in practical decision-making in supply chain management; The total costs of forest chips with intermodal composite container supply chains were lower than traditional options in all scenarios; The most advantageous way to expand the procurement area for forest chips is either to use composite container trucks or start using train transportation instead of trucks for procurement from longer distances.
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Cost-efficient solutions of supply chains for energy wood are required as part of endeavors to reach targets for renewable energy utilization. Long-distance railway transportation is an interesting area of research, especially for high-volume sites where the forest-to-site distance is considerable and rail facilities already exist. The aim of the study was to compare the cost-efficiency of an intermodal container supply chain and traditional multi-modal supply chain with corresponding direct truck logistics for long-distance transportation of forest chips. In the study, site-dependent information for forest biomass transport was integrated into a simulation model to calculate the cost-efficiency of logistic operations related to forest chips transportation in central Finland. The model was tested with several truck and railway transportation scenarios for varying demand of forest chips at the case power plant. The total costs of traditional supply chains were found to be 5–19% more expensive than container supply chain scenarios. The total unit costs of forest chips varied between 15.3 and 20.0 €/MWh depending on the scenario. It is concluded on the basis of the scenario study that intermodal light-structure container logistics and railway transportation could be developed as a viable option for large-scale supply of forest chips.
  • Karttunen, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland E-mail: kalle.karttunen@lut.fi (email)
  • Lättilä, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland E-mail: lauri.lattila@lut.fi
  • Korpinen, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland E-mail: olli-jussi.korpinen@lut.fi
  • Ranta, Lappeenranta University of Technology, LUT Savo Sustainable Technologies, Sammonkatu 12, FI-50130 Mikkeli, Finland E-mail: tapio.ranta@lut.fi
article id 1002, category Research article
Pentti Niemistö. (2013). Effect of growing density on biomass and stem volume growth of downy birch stands on peatland in Western and Northern Finland. Silva Fennica vol. 47 no. 4 article id 1002. https://doi.org/10.14214/sf.1002
Keywords: yield; thinning; silviculture; mortality; pulpwood; stand density; crown; energy-wood
Highlights: The thinning response in young downy birch stands was low and the mortality of merchantable stems was tolerable even in dense unthinned thickets during the rotation of 50 years; The production of above-ground woody biomass and stem volume or even the production of pulpwood increased with stand density, with these values being greatest for unthinned or very lightly thinned plots.
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The objective of the study was to ascertain the relationship of thinning intensity of downy birch (Betula pubescens Ehrh.) stands with height, crown, and diameter development as well as pulpwood, stem volume, and biomass increment using long-term (20−30 years) field experiments. Diameter growth of birches increased with thinning intensity during the first 15 years from thinning in all development phases, though after that it did so only for the youngest stands. The thinning response was low. Thinning intensity had no influence on increase in height. In terms of stem volume with bark, the mortality in unthinned stands during the study period was 30–45 m3 ha-1. The mean stem number in unthinned birch thickets fell from 25 000 ha-1 at a dominant height of 7 m to 3000 ha-1 at 18 m. The stem volume increment over the first 15 years was highest (5–6 m3 ha-1 a-1) on the very lightly thinned or unthinned plots, but later there was no significant difference between initial thinning intensities. The maximum above-ground leafless biomass (over 100 Mg ha-1) was achieved on very lightly thinned plots. Also, the total production (including thinning removal) of biomass or stem volume or even the production of pulpwood increased with stand density, with these values being greatest for very lightly thinned or unthinned plots. During 50-year rotation, the highest leafless above-ground biomass production was 2.5 Mg ha-1 a-1 as a mean value from the experiments. The highest mean annual production of pulpwood (d > 6.5 cm) was 3.2 m3 ha-1 a-1, and, in practice, no saw timber or veneer timber was produced, because of the small size and low quality of the stems. A thinning in downy birch stands increased slightly the size of stems to be removed in future cuttings, but with exception for very light thinning it decreased the production of biomass and merchantable wood.
  • Niemistö, Finnish Forest Research Institute, Parkano Unit, FI-39700 Parkano, Finland E-mail: pentti.niemisto@metla.fi (email)
article id 938, category Research article
Lars Karlsson, Tommy Mörling, Urban Bergsten. (2013). Influence of silvicultural regimes on the volume and proportion of juvenile and mature wood in boreal Scots pine. Silva Fennica vol. 47 no. 4 article id 938. https://doi.org/10.14214/sf.938
Keywords: fibre length; stand density; juvenile wood
Highlights: Initial stand densities have a large impact on the proportion of mature wood within trees throughout most of their life cycle; The difference between regimes in volume of long fibres in crop trees could be substantial; Long-term silvicultural strategies implemented at juvenile stand ages can be important tools in order to produce wood raw material suited for specific end-uses.
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Trees from 48 to 78 years old, exposed to three different long-term silvicultural regimes, were examined for transition ages between juvenile (JW), transition (TW) and mature wood (MW), total wood volume and proportions of the same wood types, as defined by fibre length. Twenty one sample trees were collected at sites with similar growing conditions within the same geographical area. Stem discs and fibre samples from breast height (BRH), 20% of tree height, green crown height and 70% of tree height were analysed. Trees growing in an environment with few neighboring trees (Sparse regime) started to produce MW, on average, five years later at BRH and six to nine years later at 20% of total tree height than trees in stands with high stem numbers (Dense regime) and trees growing in stands where the stem number had been heavily reduced after an initial high stand density (Dense/Sparse regime). For all regimes, the greatest mean fibre length was found below the green crown and high initial stem numbers were found to positively influence fibre length. The proportion of MW in the whole stem was 34% at Sparse regime sites, 57–69% at Dense/Sparse sites and 63–64% in sites where there was a Dense regime. The proportion of MW was significantly lower for trees from the Sparse regime on each stem section compared. In conclusion, the results suggest that the initial condition a tree faces affects the stem wood properties and quality output at the end of the rotation period.
  • Karlsson, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: lars.karlsson@slu.se (email)
  • Mörling, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: tommy.morling@slu.se
  • Bergsten, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: urban.bergsten@slu.se
article id 954, category Research article
Anna-Maria Eriksson, Jörgen Olsson, Bengt Gunnar Jonsson, Sara Toivanen, Mattias Edman. (2013). Effects of restoration fire on dead wood heterogeneity and availability in three Pinus sylvestris forests in Sweden. Silva Fennica vol. 47 no. 2 article id 954. https://doi.org/10.14214/sf.954
Keywords: Scots pine; CWD; prescribed burning; decay stage; charred wood
Abstract | Full text in HTML | Full text in PDF | Author Info
Restoration fires are increasingly used as a conservation tool in Sweden to recreate forests with characteristics of previous forests that were periodically disturbed by fires and promote fire-dependent species. Restoration fires can result in large inputs of fresh dead wood, but there are risks of losing some of the existing, pre-fire dead wood. To assess these counteracting effects we studied the heterogeneity and availability of dead wood before and after three restoration fires in boreal Scots pine forests. Specifically, we studied volumes of stumps, high stumps, snags and logs. The fires decreased the total volume of pre-fire dead wood (23-41%) and consumed logs in late decay stages (26-54%) to a higher extent than logs in earlier stages. The input of new fresh dead wood after the fires exceeded losses of pre-fire dead wood and resulted in a net increase of dead wood in all three sites. The added dead wood consisted of fresh snags killed by the fires. Fire also affected log characteristics: reducing their vegetation coverage (60-98%), decreasing their ground contact (4-50%) and increasing their surface area of charred wood (>50%). Such changes have important consequences for the micro environmental conditions inside logs, but have been rarely studied in relation to restoration fires. Our results show that restoration fire causes changes in dead wood availability and characteristics of logs. The results imply that ideally stands with low abundance of rare and heavily decayed wood substrates should be burned to optimize dead wood values. Alternatively, management practices should include protection of these substrates during restoration fires.
  • Eriksson, Department of Natural Sciences, Mid Sweden University, SE-851 70, Sundsvall, Sweden E-mail: anna-maria.eriksson@miun.se (email)
  • Olsson, Department of Ecology and Environmental Science, Umeå University, SE-901 87, Umeå, Sweden E-mail: jorgen.m.olsson@slu.se
  • Jonsson, Department of Natural Sciences, Mid Sweden University, SE-851 70, Sundsvall, Sweden E-mail: bengt-gunnar.jonsson@miun.se
  • Toivanen, Department of Natural Sciences, Mid Sweden University, SE-851 70, Sundsvall, Sweden E-mail: sara.toivanen@lansstyrelsen.se
  • Edman, Department of Natural Sciences, Mid Sweden University, SE-851 70, Sundsvall, Sweden E-mail: mattias.edman@miun.se
article id 930, category Research article
Raffaele Spinelli, Eugenio Cavallo, Lars Eliasson, Alessio Facello. (2013). Comparing the efficiency of drum and disc chippers. Silva Fennica vol. 47 no. 2 article id 930. https://doi.org/10.14214/sf.930
Keywords: productivity; biomass; wood; energy; fuel
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The study compared the effect of chipper type on productivity, power demand, fuel consumption and product quality. Tests were conducted on two commercial chipper models, a disc and a drum chipper. Both chippers had the same diameter capacity, were applied to the same tractor and fed with the same feedstock types. Fifteen replications were conducted per machine and for each of four different feedstock types, reaching a total of 120 tests. The disc chipper had a higher energy efficiency and used 19% less fuel per unit product, possibly due to its simpler design, integrating comminuting and discharge system in one synergic device. In contrast, the drum chipper was 8% more productive, since it cut with the same energy all along the length of its knives. The drum chipper produced smaller chips, with a higher incidence of fines. Feedstock type had a strong effect on productivity, energy efficiency and product quality. The effect of feedstock type was mainly related to piece size, and may be stronger than the effect of chipper type. Further studies should determine the effect of blade wear on the relative performance of the two chipper types.
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, Sesto Fiorentino (FI), Italy E-mail: spinelli@ivalsa.cnr.it (email)
  • Cavallo, CNR IVALSA, Via Madonna del Piano 10, Sesto Fiorentino (FI), Italy E-mail: e.cavallo@imamoter.cnr.it
  • Eliasson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: lars.eliasson@skogforsk.se
  • Facello, CNR IVALSA, Via Madonna del Piano 10, Sesto Fiorentino (FI), Italy E-mail: a.facello@ima.to.cnr.it
article id 904, category Research article
Raul Fernandez-Lacruz, Fulvio Di Fulvio, Dan Bergström. (2013). Productivity and profitability of harvesting power line corridors for bioenergy. Silva Fennica vol. 47 no. 1 article id 904. https://doi.org/10.14214/sf.904
Keywords: accumulating felling head; clearing; maintenance; motor-manual; power grid; wood fuel
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Trees growing under the wires and around the pylons carrying power lines (PL) represent a significant threat to the power supply because they can cause power outages and damage. The vegetation in these PL corridors is cleared motor-manually on a regular basis, which represents about 50% of the PL maintenance costs. In Sweden, PL corridors account for 140 000 ha of productive forest land, with an estimated bioenergy potential of 3 TWh/year. The aim of this study was to measure the productivity of a harvester (with an accumulating felling head) and a forwarder, performing PL corridor clearing (with the collection of whole trees for energy use) and to calculate how the cost and economic profitability is dependent on tree height, biomass removal, harvested area, forwarding distance and wood fuel price. The study also compared the economic profitability of the mechanized harvesting system with motor-manual clearing. Experimental units were inventoried along a PL corridor in central Sweden and a time study of one harvester and one forwarder (with a single operator per machine), working in those units, was carried out. The results showed that if the tree height was greater than about 6 m, the mechanized harvesting system became a more cost-efficient alternative, when compared to motor-manual clearing, but it was also found that mechanized clearing is not always the most cost-effective option. Nevertheless, mechanization of PL clearing has a huge potential for expansion, requiring further research in the combined management of the PL corridors and side areas.
  • Fernandez-Lacruz, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: raul.fernandez@slu.se (email)
  • Di Fulvio, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: fulvio.di.fulvio@slu.se
  • Bergström, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: dan.bergstrom@slu.se
article id 901, category Research article
Luis A. Apiolaza, Rosa M. Alzamora. (2013). Building deployment portfolios for genotypes under performance instability. Silva Fennica vol. 47 no. 1 article id 901. https://doi.org/10.14214/sf.901
Keywords: Pinus radiata; wood quality; breeding objectives; clonal portfolio; deployment portfolio; genotype by environment interaction
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We used portfolio theory to analyze the tradeoffs between returns and performance instability of deployment units for Pinus radiata D. Don. We considered three groups of 34 trees each grown to produce appearance lumber, structural lumber, or both. Risk was based on the variability of tree returns in scenarios of changing volume, wood stiffness and presence of resin defects due to genotype by environment interaction inducing both changes of scale and differential tree response to environmental scenarios. The return of structural trees was highly variable with a mean of 3.11 NZ $/stem/year, followed by appearance-structural trees (3.48 NZ $/stem/year). In contrast, appearance trees had the lowest returns (1.99 NZ $/stem/year) and variability. The portfolio model selected structural trees in high-risk scenarios, but selection was apportioned between structural and appearance-structural trees as the risk decreased. The model selected only appearance trees for high-risk aversion. The analysis also considered silvicultural regimes, where the appearance-structural regime was selected under high variability. As risk decreased the appearance grades regime was also selected. The structural regime was rarely selected due to the variability of stiffness between trees. Using genotypes improved for stiffness could increase the expected value and reduce variability for structural purposes, making the structural regime more appealing.
  • Apiolaza, School of Forestry, University of Canterbury, Private Bag 4800, 8042 Canterbury, New Zealand E-mail: luis.apiolaza@canterbury.ac.nz (email)
  • Alzamora, Instituto de Manejo Forestal, Universidad Austral, Valdivia, Chile E-mail: ralzamor@uach.cl
article id 899, category Research article
Franz Holzleitner, Christian Kanzian, Norbert Höller. (2013). Monitoring the chipping and transportation of wood fuels with a fleet management system. Silva Fennica vol. 47 no. 1 article id 899. https://doi.org/10.14214/sf.899
Keywords: forest fuel; supply chain; monitoring; logistic; fleet management; wood chips
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Controlling and organizing the complex forest-to-consumer supply chain of wood fuels is a challenging task, especially for the chipping and transport processes. Truck mounted chippers and transport trailer-trucks must be scheduled to minimize delay to be profitable. Job management within the supply chain, including machine activity based controlling, offers a new way to increase efficiency and productivity. However, detailed data are required to detect and analyze potential gaps and improve forest fuel supply. Generally, data regarding the wood fuel supply chain process are obtained from extensive time studies that are based on a specific process step. Although time studies can detect details during the production of forest fuels, they only describe certain time frames. Long-term data that are recorded during the entire year could encompass seasonal and short term effects. This study aims to monitor the forest fuel supply processes (semi-automated), specifically regarding time and fuel consumption. Large data sets were automatically and efficiently gathered with little effort by drivers and operators. Data were recorded with fleet management equipment for more than 14 months. Vehicle data, including GPS data, were logged at an interval of one minute. Data management was conducted in a pre-configured database that contained pre-defined reports and were run by the Institute of Forest Engineering, Vienna. Work step assignments were implemented with Structured Query Language (SQL)-routines by using the raw machine activities data and GPS. The chipping and transport activities of more than 240 loads were analyzed by focusing on fuel consumption, time needed and traffic. The average distance between chipping sites and plants was approximately 54 kilometers. Fuel consumption from transport reached 50 l/100 km. The chipping unit reached a productivity of 12.8 odt/PSH15 and had a fuel consumption of 58 liters per operating hour.
  • Holzleitner, Institute of Forest Engineering, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Peter Jordanstrasse 82/3, 1190 Vienna, Austria E-mail: franz.holzleitner@boku.ac.at (email)
  • Kanzian, Institute of Forest Engineering, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Peter Jordanstrasse 82/3, 1190 Vienna, Austria E-mail: christian.kanzian@boku.ac.at
  • Höller, Institute of Forest Engineering, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Peter Jordanstrasse 82/3, 1190 Vienna, Austria E-mail: norbert.hoeller@boku.ac.at
article id 921, category Research article
Katri Luostarinen. (2012). Tracheid wall thickness and lumen diameter in different axial and radial locations in cultivated Larix sibirica trunks. Silva Fennica vol. 46 no. 5 article id 921. https://doi.org/10.14214/sf.921
Keywords: wood; earlywood; latewood; fibre; Siberian larch; xylem
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In Larix trunks the properties of wood differ clearly radially, but the axial differences are smaller as well as being less studied. Wood anatomy is in particular poorly studied, even though all other wood properties derive from cell and tissue structure. The aim of this study was to chart variation in tracheid size (double wall thickness (2CWT), diameter of lumen (RD)) within fast grown cultivated Siberian larch (Larix sibirica Ledeb.) trunks. The differences in 2CWT and RD were clear between earlywood (EW) and latewood (LW), 2CWT increasing clearly less in EW than in LW towards the bark, while RD stayed quite stable in LW but in EW increased markedly towards the bark. The difference in 2CWT between EW and LW increased towards the upper trunk. In conclusion, the radial variation in RD and 2CWT was different between the butt and other studied heights. As the difference in 2CWT between EW and LW was smaller at the butt than the upper portion of the trunk, the wood was the most homogenous at the butt.
  • Luostarinen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: katri.luostarinen@uef.fi (email)
article id 910, category Research article
Gernot Erber, Christian Kanzian, Karl Stampfer. (2012). Predicting moisture content in a pine logwood pile for energy purposes. Silva Fennica vol. 46 no. 4 article id 910. https://doi.org/10.14214/sf.910
Keywords: moisture content; modelling; natural wind drying of fuel wood; log pile
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Determining the moisture content of naturally dried fuel stock without frequent measuring is a problem still unsolved. Modelling moisture content based on automatically captured meteorological data could provide a solution. An accurate model would allow the drying period and the point of chipping to be optimised. For the experimental study, a metal frame supported by load sensors and loaded with 17 tons of logwood was set up next to a meteorological station. A multiple linear regression model was used to link meteorological and load data to provide a formula for determining the moisture content. The pile dried for a period of 14 months (average temperature of 7.3 °C, a humidity of 81%, and 777 mm of rainfall). The overall moisture content dropped from 50.1% to 32.2%. The regression model, which based on daily means and sums of meteorological parameters, provided a mean deviance from the observed curve of –0.51%±0.71% within the period of investigation. Relative humidity was found to be most important parameter in drying. Increased moisture content resulting from rainfall greater than 30 mm per day reverted back to pre-rainfall values within two to three days, if no other rainfall events followed. Covering the pile would have a positive effect on the drying performance. In terms of economic benefit it could be shown that natural drying is beneficial. Overall this study shows that meteorological data used in site specific drying models can adequately predict the moisture content of naturally dried logwood.
  • Erber, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria E-mail: gernot.erber@boku.ac.at (email)
  • Kanzian, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria E-mail: christian.kanzian@boku.ac.at
  • Stampfer, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria E-mail: karl.stampfer@boku.ac.at
article id 51, category Research article
Sanna Hautamäki, Antti Mutanen, Jari Viitanen. (2012). Substitution in the Finnish forest industry’s roundwood procurement. Silva Fennica vol. 46 no. 3 article id 51. https://doi.org/10.14214/sf.51
Keywords: roundwood procurement; imports; substitution; translog cost function
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In this study, the interaction and substitution between domestic and imported roundwood in the Finnish forest industry’s wood procurement is analysed by timber assortments. The results from the translog cost function approach and quarterly data of the total wood procurement and its components during the euro regime indicate that, to a certain extent, the Finnish forest industry has had the possibility of substituting imported roundwood volumes between countries in the Baltic Sea region. Contrary to earlier studies, also in the case of Russian birch pulpwood, the most important imported timber assortment, the results suggest that Russian birch pulpwood has rather substituted for than complemented the domestic supply in Finland. The increase in roundwood export duties in Russia has had a statistically significant effect on the trade in birch pulpwood and spruce sawlogs. Moreover, the results confirm the earlier findings of a rigid demand for roundwood in Finnish roundwood markets.
  • Hautamäki, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: sh@nn.fi
  • Mutanen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: antti.mutanen@metla.fi (email)
  • Viitanen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jv@nn.fi
article id 48, category Research article
Jyrki Hytönen, Lasse Aro. (2012). Biomass and nutrition of naturally regenerated and coppiced birch on cutaway peatland during 37 years. Silva Fennica vol. 46 no. 3 article id 48. https://doi.org/10.14214/sf.48
Keywords: Betula; biomass production; coppicing; fertilization; PK fertilizers; wood ash
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Biomass production and nutrient use of birch thickets with a mixture of willow on a cut away peatland in southern Finland over a period of 37 years was studied. Dense, naturally regenerated 16-year-old birch stands were cut down, fertilized with either wood ash (P 108 and K 339 kg ha–1) or PK fertilizer (P 50 and K 95 kg ha–1) or left unfertilized. The biomass production of the coppiced stands and one uncut stand was monitored for a period of 21 years. Soil nutrient and foliar nutrient concentrations were analyzed several times during the study period. Ash fertilization supplied more nutrients than PK fertilization and increased the soil nutrient amounts more. The foliar phosphorus concentration of birch on control plots indicated a severe phosphorus deficiency which was removed by PK and ash fertilization. Fertilization did not increase nutrient concentrations of the stem (wood + bark) nor the amount of nutrients bound in the biomass. Two energy wood rotations (16+21 years) produced 124–158 Mg ha–1 of leafless, above-ground biomass altogether corresponding to 61–78 Mg ha–1 of carbon. The highest biomass yield was achieved with a rotation of 37 years in the uncut stand (211 Mg ha–1). Corresponding values for mean annual increment (MAI) were 3.4–4.3 Mg ha–1 and 5.7 Mg ha–1. This study shows that the length of the rotation for birch in energy wood production should be longer than 21 years. PK and ash fertilization increased the biomass of coppiced 21-year-old birch by 23 Mg ha–1 and 33 Mg ha–1, respectively.
  • Hytönen, Finnish Forest Research Institute, Kannus, Finland E-mail: jyrki.hytonen@metla.fi (email)
  • Aro, Finnish Forest Research Institute, Kannus, Finland E-mail: lasse.aro@metla.fi
article id 47, category Research article
Iulian Dragotescu, Daniel D. Kneeshaw. (2012). A comparison of residual forest following fires and harvesting in boreal forests in Quebec, Canada. Silva Fennica vol. 46 no. 3 article id 47. https://doi.org/10.14214/sf.47
Keywords: forest fires; biodiversity; boreal mixedwood; clearcuts; disturbances; residual forests; tree retention
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Residual forests are a key component of post-burned areas creating structure within burns and providing habitat and seed sources. Yet, despite their importance to biodiversity and ecosystem processes there is little information on how similar or different residuals in burned landscape are to harvested landscapes. Our goal was to examine and compare the density, size, shape, and spatial arrangement of residual forest vegetation after fire and clearcutting. We evaluated residual forest in two locations within the boreal mixedwood region of Quebec, Canada using aerial photo interpretation and ArcGIS 9.1 software. We found residual stands to be larger and more abundant in harvested zones relative to sites affected by fire. Differences with respect to shape and spatial arrangement of residual forest were also observed among disturbance types. Factors such as proximity to watercourses, watercourse shape, and physiography affected residual abundance and spatial distribution. Residual forest in harvested zones tended to be more elongated with greater edge due to rules governing forest operations. Despite greater quantity of residual forest in harvested areas than fires, managers should still be prudent as the surrounding forest matrix is reduced in many managed landscapes.
  • Dragotescu, Université du Québec à Montréal, Centre d’Étude de la Forêt (CEF), Montreal, Quebec, Canada E-mail: idragot@hotmail.com (email)
  • Kneeshaw, Université du Québec à Montréal, Centre d’Étude de la Forêt (CEF), Montreal, Quebec, Canada E-mail: ddk@nn.ca
article id 44, category Research article
Anabel Aparecida de Mello, Leif Nutto, Karla Simone Weber, Carlos Eduardo Sanquetta, Jorge Luis Monteiro de Matos, Gero Becker. (2012). Individual biomass and carbon equations for Mimosa scabrella Benth. (bracatinga) in southern Brazil. Silva Fennica vol. 46 no. 3 article id 44. https://doi.org/10.14214/sf.44
Keywords: carbon offsets; forest inventory; firewood; modeling; tree compartments
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Mimosa scabrella Benth. is an important native species of southern Brazil widely used for energy and promising for reforestation carbon offsets. Quantification of biomass and carbon stock is valuable for both purposes. From a forest inventory conducted in southern Brazil, data of M. scabrella were analyzed. Thirty sample trees were felled, excavated and weighed in the field and brought to laboratory for biomass and carbon determination. The total aboveground biomass represented 85% of the tree biomass, while roots corresponded to 15%. Correlation matrix of diameter at 1.3 m height (D), tree height (H) versus total and compartment biomass (P) indicated strong association between tree dimensions and biomasses. Five regression models were tested and equations were fitted to data of five biomass compartments and total tree biomass. The best fitting model for total biomass was P = –0.49361 + 0.034865 x D2H whereas for the partial biomass of the compartments was lnP = β0 + β1 x ln(D) + β2 lnH. Carbon concentration was statistically significantly different in foliage than in other compartments. Three approaches of calculating carbon stocks were evaluated and compared to actual data: 1) Estimated total biomass x weighted mean carbon concentration; 2) Estimated partial (compartment) biomass x compartment average carbon concentration; and 3) Carbon regression equations. No statistical difference was detected among them. It was concluded that biomass equations fitted in this study were accurate and useful for fuelwood and carbon estimations.
  • de Mello, Federal University of Sergipe, Brazil E-mail: aadm@nn.br
  • Nutto, Federal University of Paraná, Brazil E-mail: lnutto.ufpr@gmail.com (email)
  • Weber, Federal University of Paraná E-mail: ksw@nn.br
  • Sanquetta, Carlos Eduardo Sanquetta E-mail: ces@nn.br
  • Monteiro de Matos, Jorge Luis Monteiro de Matos E-mail: jlmdm@nn.br
  • Becker, University of Freiburg, Institute of Forest Utilization and Work Science, Germany E-mail: gb@nn.de
article id 43, category Research article
Anni Markkanen, Panu Halme. (2012). Polypore communities in broadleaved boreal forests. Silva Fennica vol. 46 no. 3 article id 43. https://doi.org/10.14214/sf.43
Keywords: birch; deciduous; slash and burn; species-area relationship; wood-inhabiting fungi
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The cover and extent of boreal broadleaved forests have been decreasing due to modern forest management practices and fire suppression. As decomposers of woody material, polypores are ecologically important ecosystem engineers. The ecology and conservation biology of polypores have been studied intensively in boreal coniferous forests. However, only a few studies have focused on the species living on broadleaved trees. To increase knowledge on this species group we conducted polypore surveys in 27 broadleaved forests and 303 forest compartments (539 ha) on the southern boreal zone in Finland and measured dead wood and forest characteristics. We detected altogether 98 polypore species, of which 13 are red-listed in Finland. 60% of the recorded species are primarily associated with broadleaved trees. The number of species in a local community present in a broadleaved forest covered approximately 50 species, of which 30–40 were primarily associated with broadleaved trees. The size of the inventoried area explained 67% of the variation in the species richness, but unlike in previous studies conducted in coniferous forests, dead wood variables as well as forest structure had very limited power in explaining polypore species richness on forest stand level. The compartments occupied by red listed Protomerulius caryae had an especially high volume of living birch, but otherwise the occurrences of red-listed species could not be predicted based on the forest structure.
  • Markkanen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: anni.e.markkanen@gmail.com (email)
  • Halme, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: ph@nn.fi
article id 87, category Research article
Radek Bace, Miroslav Svoboda, Pavel Janda. (2011). Density and height structure of seedlings in subalpine spruce forests of Central Europe: logs vs. stumps as a favourable substrate. Silva Fennica vol. 45 no. 5 article id 87. https://doi.org/10.14214/sf.87
Keywords: Norway spruce; Picea abies; coarse woody debris; microsite; natural regeneration
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Decaying logs and stumps provide an important seedling substrate in natural subalpine forests. However, only stumps present such a role in managed forests. The aim of this study was to assess the differences in the process of seedling colonization between logs and stumps. The study was carried out in the Czech Republic, in two old-growth subalpine spruce forests located in the Bohemian Forest and Ash Mts., dominated by Athyrium distentifolium Opiz and Vaccinium myrtillus L. undergrowth, respectively. Norway spruce (Picea abies (L.) Karst.) regeneration growing on logs, stumps and non-coarse woody debris (CWD) microsites was surveyed. Regeneration (height 0–2.0 m) densities exceeded 5000 individuals per ha on both sites. The average density of P. abies regeneration per square meter of substrate was 0.3-5.7-19.6 and 0.5-3.8-11.0 on non-CWD microsites, logs and stumps, located in A. distentifolium and V. myrtillus undergrowth, respectively. Stumps and non-CWD microsites dominated by V. myrtillus, supported a higher proportion of taller seedlings per plot compared to the small seedlings growing on logs and non-CWD dominated by A. distentifolium ground-cover. The disproportion in regeneration densities between the stumps and the original logs decreased with increasing stages of decay. The tallest regeneration growing on stumps (root-soil plates) was significantly older than that growing on the logs (stems). Based on these two latter findings, the stumps appeared to provide suitable seedling substrates several years earlier than the logs did. Therefore, we conclude that the stumps play a more important role (relative to their covered area, 21–28 m2 ha–1) in terms of suitable microsites for regeneration, than the logs do.
  • Bace, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: bace@fld.czu.cz (email)
  • Svoboda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: ms@nn.cz
  • Janda, Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Prague, Czech Republic E-mail: pv@nn.cz
article id 85, category Research article
Ville A.O. Selonen, Maija Mussaari, Tero Toivanen, Janne S. Kotiaho. (2011). The conservation potential of brook-side key habitats in managed boreal forests. Silva Fennica vol. 45 no. 5 article id 85. https://doi.org/10.14214/sf.85
Keywords: forest management; saproxylic species; dead wood; vegetation
Abstract | View details | Full text in PDF | Author Info
Today, maintaining biodiversity is included in the targets of boreal forest management. A widespread approach in northern Europe is to identify and preserve woodland key habitats within managed forests. Woodland key habitats are expected to be patches that host populations of threatened and declining species, and the preservation of these patches is assumed to enable the persistence of the focal species in the landscape. In Finland, the criteria for selecting woodland key habitats are defined in the Finnish Forest Act, and the selection has been done by forest practitioners. Our objective was to determine whether the surroundings of boreal brooks and rivulets qualified as key habitats are truly different from brook-side habitats not granted the key habitat status, and whether the brook-side habitats of the two types differ from the forest matrix managed for timber production. We found that the two brook-side habitats were in most aspects rather alike but there was a difference in the composition of ground vegetation assemblages. In contrast, the control forests were distinct from the brook-sides in terms of dead wood, species richness and assemblages of polypores, species richness of epiphytic mosses, and the composition of beetle assemblages. We conclude that brook-sides in general provide an important habitat clearly diverging from the surrounding matrix but that the conservation value of the brook-sides granted the key habitat status may not be substantially larger than that of the brook-sides without the status.
  • Selonen, University of Jyväskylä, Department of Biological and Environmental Sciences, Lahti, Finland E-mail: ville.selonen@juy.fi (email)
  • Mussaari, University of Jyväskylä, Department of Biological and Environmental Sciences, Lahti, Finland E-mail: mm@nn.fi
  • Toivanen, University of Jyväskylä, Department of Biological and Environmental Sciences, Lahti, Finland E-mail: tt@nn.fi
  • Kotiaho, University of Jyväskylä, Department of Biological and Environmental Sciences, Lahti, Finland E-mail: jsk@nn.fi
article id 81, category Research article
Tuomas Aakala. (2011). Temporal variability of deadwood volume and quality in boreal old-growth forests. Silva Fennica vol. 45 no. 5 article id 81. https://doi.org/10.14214/sf.81
Keywords: forest dynamics; Picea abies; coarse woody debris; range of variability
Abstract | View details | Full text in PDF | Author Info
Reference deadwood volumes from natural forests for forest management and restoration are often derived from one-time measurements or from repeated measurements over short time-scales. Such an approach often assumes an equilibrium state between tree mortality and decomposition, which is questionable in many boreal forest ecosystems due to the occurrence of allogenic disturbances. Using a simulation model based on empirical estimates of tree mortality, disturbance chronologies and models of wood decay class dynamics, this study aimed at characterizing variability in the volume and quality of deadwood for the past 200 years. The variability of deadwood volumes in old-growth forests, arising from differences in disturbance regimes and differing decay rates, was exemplified in two areas of Picea abies-dominated forests in northern Europe. The results imply that with stable deadwood input and slow decay rates the deadwood volume may be in an equilibrium state. On the contrary, if moderate-severity disturbances occur such a state seems improbable. Both study areas displayed continuity in deadwood availability, although temporary paucity in the early decay classes with shortest residence times was also observed. The results stress the importance of understanding the dynamic nature of deadwood in old-growth forests, instead of the traditional view of deadwood as a static ecosystem component.
  • Aakala, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: tuomas.aakala@helsinki.fi (email)
article id 80, category Research article
Mari T. Jönsson, Shawn Fraver, Bengt Gunnar Jonsson. (2011). Spatio-temporal variation of coarse woody debris input in woodland key habitats in central Sweden. Silva Fennica vol. 45 no. 5 article id 80. https://doi.org/10.14214/sf.80
Keywords: boreal forest; Picea abies; dendrochronology; disturbance dynamics; tree mortality; woodland key habitats; windstorms
Abstract | View details | Full text in PDF | Author Info
The persistence of many saproxylic (wood-living) species depends on a readily available supply of coarse woody debris (CWD). Most studies of CWD inputs address stand-level patterns, despite the fact that many saproxylic species depend on landscape-level supplies of CWD. In the present study we used dated CWD inputs (tree mortality events) at each of 14 Norway spruce (Picea abies) dominated woodland key habitat sites to analyze the spatial and temporal patterns of CWD additions between 1950 and 2002 within a small landscape in central Sweden. We found that inputs were episodic within sites, where local windstorms created pulses in CWD input. Pulses occurred simultaneously in many sites, yielding landscape-level synchrony of CWD input. These synchronous pulses, and importantly, the breaks between pulses, may have negative implications for saproxylic species that are dependent on large volume inputs of freshly killed Norway spruce. In addition, the inherent small size and relative isolation of these sites may further increase extinction risks due to stochastic events. However, background CWD input rates occurring between pulses varied substantially among sites, presumably the result of the sites’ varied histories and structural characteristics. This finding suggests that the different sites have varied abilities to provide habitat for saproxylic species during periods with low landscape-level input of CWD.
  • Jönsson, Department of Ecology, SLU, P.O. Box 7044, SE-750 07 Uppsala, Sweden (current); Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Sundsvall, Sweden E-mail: mari.jonsson@slu.se (email)
  • Fraver, U.S. Forest Service, Northern Research Station, Grand Rapids, Minnesota, USA (current); Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Sundsvall, Sweden E-mail: sf@nn.us
  • Jonsson, Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Sundsvall, Sweden E-mail: bgj@nn.se
article id 79, category Research article
Jean-Philippe Légaré, Christian Hébert, Jean-Claude Ruel. (2011). Alternative silvicultural practices in irregular boreal forests: response of beetle assemblages. Silva Fennica vol. 45 no. 5 article id 79. https://doi.org/10.14214/sf.79
Keywords: biodiversity; old-growth forest; irregular stands; selection cutting; coarse woody debris; sustainable management
Abstract | View details | Full text in PDF | Author Info
In the process of implementing sustainable management in the eastern Canadian boreal forest, we tested two selection cutting methods and compared them with two widely used practices in the boreal forest: clearcutting with protection of the advanced growth and soils and irregular shelterwood cutting leaving small merchantable stems. We used old-growth irregular stands as references in comparing the impact of these silvicultural treatments on the diversity and abundance of beetles. Three groups were targeted: saproxylic flying beetles, epigaeic saproxylic beetles and epigaeic non-saproxylic beetles. A sampling design including 320 pitfall traps and 80 multidirectional flight-interception traps was deployed in 2007. A total of 26 906 beetles was captured including 407 taxa distributed among 52 families. We found that clearcutting with protection of the advanced growth and soils and irregular shelterwood cutting leaving small merchantable stems had a greater impact on beetle communities than both selection cuttings. Canopy opening as well as the presence of snags and downed woody debris appear as important attributes for several saproxylic and non-saproxylic species. Beetle communities in selection cuttings remained more similar to those found in controls; these silvicultural treatments are new tools to implement ecosystemic and sustainable management in irregular boreal forests.
  • Légaré, Université Laval, Faculté de foresterie, de géographie et de géomatique, Pavillon Abitibi-Price, Québec, Canada E-mail: jpl@nn.ca
  • Hébert, Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec (Québec), G1V 4C7, Canada E-mail: christian.hebert@rncan.gc.ca (email)
  • Ruel, Université Laval, Faculté de foresterie, de géographie et de géomatique, Pavillon Abitibi-Price, Québec, Canada E-mail: jcr@nn.ca
article id 78, category Research article
Kris Vandekerkhove, Luc De Keersmaeker, Ruben Walleyn, Frank Köhler, Luc Crevecoeur, Leen Govaere, Arno Thomaes, Kris Verheyen. (2011). Reappearance of old-growth elements in lowland woodlands in northern Belgium: Do the associated species follow? Silva Fennica vol. 45 no. 5 article id 78. https://doi.org/10.14214/sf.78
Keywords: colonisation; saproxylic species; dead wood; very large trees
Abstract | View details | Full text in PDF | Author Info
The forest cover of the western European lowland plain has been very low for centuries. Remaining forests were intensively managed, and old-growth elements like veteran trees and coarse woody debris became virtually absent. Only over the last decades have these old-growth elements progressively redeveloped in parks, lanes and forests, and have now reached their highest level over the last 500–1000 years. Biodiversity associated with these old-growth elements makes up an important part of overall forest biodiversity. The ability of species to recolonise the newly available habitat is strongly determined by limitations in their dispersal and establishment. We analyse the current status and development of old-growth elements in Flanders (northern Belgium) and the process of recolonisation by means of specific cases, focussing on saproxylic fungi and saproxylic beetles. Our results show that ‘hotspots’ of secondary old growth, even isolated small patches, may have more potential for specialised biodiversity than expected, and may provide important new strongholds for recovery and recolonisation of an important share of old-growth related species.
  • Vandekerkhove, INBO, Gaverstraat 4, B-9500 Geraardsbergen, Belgium E-mail: kris.vandekerkhove@inbo.be (email)
  • De Keersmaeker, INBO, Gaverstraat 4, B-9500 Geraardsbergen, Belgium E-mail: ldk@nn.be
  • Walleyn, INBO, Gaverstraat 4, B-9500 Geraardsbergen, Belgium E-mail: rw@nn.be
  • Köhler, Koleopterologisches Forschungsbüro, Bornheim, Germany E-mail: fk@nn.de
  • Crevecoeur, Genk, Belgium E-mail: lc@nn.be
  • Govaere, Agency of Nature and Forests, Brussels, Belgium E-mail: lg@nn.be
  • Thomaes, INBO, Gaverstraat 4, B-9500 Geraardsbergen, Belgium E-mail: at@nn.be
  • Verheyen, Ghent University, Laboratory of Forestry, Gontrode, Belgium E-mail: kv@nn.be
article id 447, category Research article
Jim Kiser. (2011). Histochemical and geometric alterations of sapwood in coastal Douglas-fir following mechanical damage during commercial thinning. Silva Fennica vol. 45 no. 4 article id 447. https://doi.org/10.14214/sf.447
Keywords: thinning; sapwood; compartmentalization; damages; Pseudotsuga menziesii
Abstract | View details | Full text in PDF | Author Info
Histochemical and geometric alterations to sapwood in mechanically damaged Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco) trees were quantified 14 years after thinning. Discoloration and decay were measured in felled damaged and undamaged trees. Compartmentalized walls were identified and measured macroscopically. Sapwood to heartwood ratio was measured incrementally along the boles. Results showed a distinct reaction zone forming at the time of injury. Compartmentalized walls 1–3 were less distinct and heavily resinous streaking was evident in extant tissues, particularly in the axial direction. Post-damaged sapwood was burl-like for 4–6 years and tracheids contained resin-filled lumina. Damaged wood volumes were modeled by multiple regression. Wound depth, wound area, and diameter inside bark (DIB) accounted for 73% of the discolored volume (p = 0.02). DIB alone accounted for just over 55% of the response. Post-damaged sapwood averaged 15 mm (SE = 2.3 mm) greater in width on the side opposite the damage along the length of the boards. Wound area explained just over 65% of this response (p = 0.003). Sapwood area was not significantly different between damaged and control trees (p = 0.56). Results indicate that wounded Douglas-fir trees may slow conversion of sapwood to heartwood on the bole side opposite the wound, possibly as a response to maintain sapwood area necessary for physiological maintenance of the existing crown. About 19% of the lower bole volume in damaged trees was affected by discoloration and secondarily by structural changes. Reduction in value of the lower log can be as high as 19% by conventional bucking practices. Alternatives are presented to reduce the value loss to between 2.5% to 3.5%.
  • Kiser, P.O. Box 3729, Pagosa Springs, Colorado, USA E-mail: jim.kiser@parelli.com (email)
article id 110, category Research article
Erlend Nybakk, Pablo Crespell, Eric Hansen. (2011). Climate for innovation and innovation strategy as drivers for success in the wood industry: moderation effects of firm size, industry sector, and country of operation. Silva Fennica vol. 45 no. 3 article id 110. https://doi.org/10.14214/sf.110
Keywords: comparative management; innovations; organisational culture; strategy; wood industry; working climate
Abstract | View details | Full text in PDF | Author Info
This study examines the relationships between firm financial performance and a) the climate for innovation and b) innovation strategy in the wood products industry. The focus is on the moderator effects of firm size, country of operation, and industry sector. Using a sample of 460 responses from chief executive officers and top managers of Norwegian and US firms, we conducted a regression analysis to probe for interaction effects. The sample included primary and secondary manufacturers of various sizes. Consistent with previous studies, we found a positive impact for both a climate for innovation and an innovation strategy on firm performance. In terms of moderation, only one interaction was found to be significant, representing a moderator effect of industry size on the climate-performance relationship. Further testing showed that secondary, large manufacturers exhibited a weaker, yet still positive, relationship between climate for innovation and performance. This low level of significant interactions suggests stability of the relationship among the main factors depicted in the model, with important implications for managers and future research. These findings indicate that a positive climate for innovation and a management committed to innovation through an innovation strategy have a positive effect on the bottom line of wood products firms. This effect holds true regardless of industry, size, or country, so most firms can benefit from the implementation of these pro-innovation practices.
  • Nybakk, Norwegian Forest and Landscape Institute, P.O. Box 115, N-1431 Ås, Norway E-mail: nye@skogoglandskap.no (email)
  • Crespell, FPInnovations (Forintek Division), Vancouver, BC, Canada E-mail: pc@nn.fi
  • Hansen, Oregon State University, College of Forestry, OR, USA E-mail: eh@nn.us
article id 109, category Research article
Ann Kristin Raymer, Terje Gobakken, Birger Solberg. (2011). Optimal forest management with carbon benefits included. Silva Fennica vol. 45 no. 3 article id 109. https://doi.org/10.14214/sf.109
Keywords: forest management; Norway spruce; substitution; CO2; greenhouse gas mitigation; optimisation; wood products
Abstract | View details | Full text in PDF | Author Info
In this paper, we analyse how optimal forest management of even aged Norway spruce changes when economic values are placed on carbon fixation, release, and saved greenhouse gas emissions from using wood instead of more energy intensive materials or fossil fuels. The analyses are done for three different site qualities in Norway, assuming present climate and with a range of CO2 prices and real rates of return. Compared to current recommended management, the optimal number of plants per ha and harvest age are considerably higher when carbon benefits are included, and increase with increasing price on CO2. Furthermore, planting becomes more favourable compared to natural regeneration. At the medium site quality, assuming 2% p.a. real rate of return and 20 euros per ton CO2, optimal planting density increases from 1500 per ha to 3000 per ha. Optimal harvest age increases from 90 to 140 years. Including saved greenhouse gas emissions when wood is used instead of more energy intensive materials or fossil fuels, i.e. substitution effects, does not affect optimal planting density much, but implies harvesting up to 20 years earlier. The value of the forest area increases with increasing price on CO2, and most of the income is from carbon. By using the current recommended management in calculations of carbon benefit, our results indicate that the forest’s potential to provide this environmental good is underestimated. The study includes many uncertain factors. Highest uncertainty is related to the accuracy of the forest growth and mortality functions at high stand ages and densities, and that albedo effects and future climate changes are not considered. As such, the results should be viewed as exploratory and not normative.
  • Raymer, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås, Norway E-mail: akr@nn.no
  • Gobakken, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås, Norway E-mail: terje.gobakken@umb.no (email)
  • Solberg, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås, Norway E-mail: bs@nn.no
article id 114, category Research article
Roy V. Rea. (2011). Impacts of moose (Alces alces) browsing on paper birch (Betula papyrifera) morphology and potential timber quality. Silva Fennica vol. 45 no. 2 article id 114. https://doi.org/10.14214/sf.114
Keywords: deciduous; browse damage; forestry; hardwood; silviculture; ungulate; wood quality
Abstract | View details | Full text in PDF | Author Info
  • Rea, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada V2N 4Z9 E-mail: reav@unbc.ca (email)
article id 112, category Research article
Mike R. Saunders, Shawn Fraver, Robert G. Wagner. (2011). Nutrient concentration of down woody debris in mixedwood forests in central Maine, USA. Silva Fennica vol. 45 no. 2 article id 112. https://doi.org/10.14214/sf.112
Keywords: Acadian Forest; hardwoods; softwoods; carbon-nitrogen ratios; decay classes; disturbance-based silviculture
Abstract | View details | Full text in PDF | Author Info
Both nutrient concentrations and pre- and post-harvest pool sizes were determined across down woody debris decay classes of several hardwood and softwood species in a long-term, natural disturbance based, silvicultural experiment in central Maine. Concentrations of N, P, Ca, Mg, Cu, Fe, and Zn generally increased 2- to 5-fold with increasing decay class. Concentrations of Mn, Al and B did not differ among decay classes, while K decreased by 20–44% from decay class 1 to class 4. C:N-ratios declined with increasing decay class, while N:P-ratios increased from decay class 1 to 2 and then plateaued with further decay. Within decay classes, softwoods generally had lower nutrient concentrations and higher C:N-ratios than hardwoods; N:P-ratios did not differ between hardwoods and softwoods. Although gap harvesting increased the size of the overall down woody debris nutrient pools, mostly through a large pulse of decay class 1 material, harvesting generally reduced the nutrients held in advanced decay classes. Pre-harvest down woody debris pools for N, P, K and Ca were 11.0, 0.6, 2.1 and 21.1 kg ha–1, respectively, while postharvest were 20.0, 1.3, 6.2 and 46.2 kg ha–1, respectively. While the gap-based silvicultural systems sampled in this study doubled the size of the pre-harvest, downed woody debris nutrient pools, the post-harvest pools were estimated to be only 3.2–9.1% of aboveground nutrients.
  • Saunders, Department of Forestry and Natural Resources, Purdue University, 715 State Street, West Lafayette, IN, USA E-mail: msaunder@purdue.edu (email)
  • Fraver, USFS Northern Research Station, Grand Rapids, MN, USA E-mail: sf@nn.us
  • Wagner, School of Forest Resources, University of Maine, Orono, ME, USA E-mail: rgw@nn.us
article id 34, category Research article
Natalie Macias, Chris Knowles. (2011). Examining the effect of environmental certification, wood source, and price on architects’ preferences of hardwood flooring. Silva Fennica vol. 45 no. 1 article id 34. https://doi.org/10.14214/sf.34
Keywords: architects; hardwood flooring; conjoint analysis; environmental certification; wood source
Abstract | View details | Full text in PDF | Author Info
This article examines the importance architects place on three factors, environmental certification, wood source, and price, when specifying hardwood flooring. Architects were presented with nine flooring scenarios, in which the three factors were present in varying levels. They were asked to rank the scenarios from the least preferred to the most preferred. Data were obtained from a mail survey of architects in Oregon and Washington, U.S.A. (n = 402). Conjoint analyses determined that architects consider price and wood source to be the most important factors when specifying hardwood flooring. Interestingly, environmental certification was considered the least important factor. The respondents were then separated into three groups for further analysis based on whether they identified themselves as more influenced by environmental factors (biocentric) or human needs (anthropocentric). This analysis showed that the biocentric group favored wood source over price and environmental certification, while the anthropocentric group favored price.
  • Macias, Oregon State University, Department of Wood Science and Engineering, 119 Richardson Hall, Corvallis, OR 97331, USA E-mail: natalie.macias@gmail.com
  • Knowles, Oregon State University, Department of Wood Science and Engineering, 119 Richardson Hall, Corvallis, OR 97331, USA E-mail: chris.knowles@oregonstate.edu (email)
article id 454, category Research article
Paula Jylhä, Olli Dahl, Juha Laitila, Kalle Kärhä. (2010). The effect of supply system on the wood paying capability of a kraft pulp mill using Scots pine harvested from first thinnings. Silva Fennica vol. 44 no. 4 article id 454. https://doi.org/10.14214/sf.454
Keywords: whole-tree harvesting; cut-to-length harvesting; integrated wood harvesting; residual value; whole-tree bundling
Abstract | View details | Full text in PDF | Author Info
The efficiencies of wood supply systems based on cut-to-length (CTL) harvesting, the harvesting of loose whole trees, and whole-tree bundling were compared using the relative wood paying capabilities (WPC) of a kraft pulp mill as decisive criteria. The WPCs from mill to stump were calculated for three first-thinning stands of Scots pine (Pinus sylvestris L.) with mean breast-height diameter of the removal of 6, 8, and 12 cm. Pulp price had a strong effect on the WPC, and the CTL system resulted in the highest WPC per m3 at stump. The savings in procurement costs and gains in energy generation from additional raw material acquired with the harvesting of loose whole trees did not compensate the losses in pulp production. Considering removal per hectare, loose whole trees gave the highest WPCs at stump in the two stands with the smallest trees and the highest proportion of additional raw material. Decrease in pulp price and increase in energy price improved the competitiveness of the whole-tree systems. In the case of whole-tree bundling, savings in transportation costs did not balance the high cutting and compaction costs, and the bundling system was the least competitive alternative.
  • Jylhä, Finnish Forest Research Institute, Kannus, Finland E-mail: paula.jylha@metla.fi (email)
  • Dahl, Aalto University School of Science and Technology, Department of Forest Products Technology, Espoo, Finland E-mail: od@nn.fi
  • Laitila, Finnish Forest Research Institute, Joensuu, Finland E-mail: jl@nn.fi
  • Kärhä, Metsäteho Oy, Helsinki, Finland E-mail: kk@nn.fi
article id 134, category Research article
Dan Bergström, Urban Bergsten, Tomas Nordfjell. (2010). Comparison of boom-corridor thinning and thinning from below harvesting methods in young dense Scots pine stands. Silva Fennica vol. 44 no. 4 article id 134. https://doi.org/10.14214/sf.134
Keywords: bioenergy; comparative time studies; energy wood; geometric thinning; pre-commercial thinnings; systematic thinnings
Abstract | View details | Full text in PDF | Author Info
At present, only a small proportion of the potential extractable bioenergy from young dense forests in Sweden is utilized. The conventional mechanized first thinning systems used in such stands suffer from low productivity, so the operation is only profitable in stands with bigger trees and high standing volumes. Conventional harvesters are used for this operation equipped with accumulating felling heads designed for handling several trees during each crane cycle. In thinning from below the felling and bunching work requires many time-consuming non-linear crane movements to avoid felling or damaging of future crop trees. However, higher productivity can be achieved when trees between strip roads are harvested in about 1 m-wide corridors with a length corresponding to the reach of the crane. We refer to this operation as boom-corridor thinning. The objective of this study was to compare felling and bunching productivity in young dense stands when employing thinning from below or boom-corridor thinning. Experiments were performed using a randomized block design involving between 4400 and 18 600 trees x ha-1 with a corresponding average tree size of 7.2 and 3.2 cm dbh, respectively. Based on the average tree being removed at a dbh of 5.7 cm, the productivity (ODt x PW-hour-1) was significant (almost 16%) higher for the boom-corridor thinning than for thinning from below treatment. At the same time, the time taken for the work element “Crane in-between” (the period between the loaded crane starting to move towards a tree and the felling head rapidly slowing down for positioning) was significantly reduced, by almost 17%. The positive results were achieved even though the operator was new to the method. To achieve a significantly higher efficiency during the felling and bunching operation, development of new harvesting equipment and operating techniques seems crucial.
  • Bergström, Swedish University of Agricultural Sciences, Dept of Forest Resource Management, Section of Planning and Operations Management, Umeå, Sweden E-mail: dan.bergstrom@srh.slu.se (email)
  • Bergsten, Swedish University of Agricultural Sciences, Dept of Forest Resource Management, Section of Planning and Operations Management, Umeå, Sweden E-mail: ub@nn.se
  • Nordfjell, Swedish University of Agricultural Sciences, Dept of Forest Resource Management, Section of Planning and Operations Management, Umeå, Sweden E-mail: tn@nn.se
article id 144, category Research article
Markku Oikari, Kalle Kärhä, Teijo Palander, Heikki Pajuoja, Heikki Ovaskainen. (2010). Analyzing the views of wood harvesting professionals related to the approaches for increasing the cost-efficiency of wood harvesting from young stands. Silva Fennica vol. 44 no. 3 article id 144. https://doi.org/10.14214/sf.144
Keywords: cost-efficiency; energy wood; early thinnings; industrial roundwood; costs; gap analysis; opinion survey
Abstract | View details | Full text in PDF | Author Info
A lot of viable guidelines are currently available for more cost-effective harvesting of energy wood and industrial roundwood (i.e. pulpwood) from young stands. The study ranked the proposed potential approaches for increasing the cost-efficiency of small-diameter (d1.3 < 10 cm) energy wood and industrial roundwood harvesting from early thinnings. Research data, based on a total of 40 personal interviews, was collected in early 2008. The interviewees were divided into four wood harvesting professional groups: 1) Managers in wood procurement organizations, 2) Forest machine contractors, 3) Forest machine manufacturers and vendors, and 4) Wood harvesting researchers. In the opinion of the respondents, there is great potential to increase the cost-efficiency of wood harvesting through improving harvesting conditions (i.e. effective tending of seedling stands, delaying harvesting operations, and pre-clearance of dense undergrowth). The interviewees also underlined that harvesting methods can be rationalized, e.g. multiple-tree handling in industrial roundwood cuttings, crane scale measurement, integrated wood harvesting, and careful selection of stands for harvesting. The strong message given by the interviewees was that the education of forest machine operators must be made more effective in the future. There would be significant possibilities for cost savings in young stands, if methods and techniques with the most potential were utilized completely in wood harvesting.
  • Oikari, Karelwood, Kontiolahti, Finland E-mail: markku.oikari@karelwood.com (email)
  • Kärhä, Metsäteho Oy, Helsinki, Finland E-mail: kk@nn.fi
  • Palander, University of Eastern Finland, Faculty of Science and Forestry, Joensuu, Finland E-mail: tp@nn.fi
  • Pajuoja, Metsäteho Oy, Helsinki, Finland E-mail: hp@nn.fi
  • Ovaskainen, University of Eastern Finland, Faculty of Science and Forestry, Joensuu, Finland E-mail: ho@nn.fi
article id 143, category Research article
Juha Laitila, Jani Heikkilä, Perttu Anttila. (2010). Harvesting alternatives, accumulation and procurement cost of small-diameter thinning wood for fuel in Central Finland. Silva Fennica vol. 44 no. 3 article id 143. https://doi.org/10.14214/sf.143
Keywords: biomass resources; multi-tree-handling; delimbed stemwood; whole trees; Finland; early thinnings; forest chips
Abstract | View details | Full text in PDF | Author Info
This study compared harvesting alternatives, accumulation and procurement costs of small-diameter thinning wood chips for fuel, when trees were harvested either as delimbed stemwood or whole trees. The calculation was made for a hypothetical plant located in Central Finland and the radius of the procurement area was 100 km via the existing road network. Cutting was done with conventional harvester head equipped with multi-tree-handling (MTH) accessories, with the logged trees being chipped at the roadside storage. The cost of delimbed stemwood chips at heating plant was 24% higher compared to the cost of whole tree chips. The availability analysis attested that delimbing lowered the regional cutting removal by 42% compared to the whole tree harvesting, when the minimum accumulation for the fuel fraction at the stand was set at 25 m3/ha. Delimbing diminishes the recovery rate at the site, resulting in a diminishing number of potential recovery sites meeting the threshold volume. However, the study showed that the forest energy potential is increased and procurement costs are reduced, if delimbed stemwood is harvested from stands where the whole tree harvesting is not acceptable due to nutrient loss or for other ecological reasons. Intelligent selection of cutting methods for different stands enables minimization of transport distance and control of procurement cost.
  • Laitila, The Finnish Forest Research Institute, Joensuu, Finland E-mail: juha.laitila@metla.fi (email)
  • Heikkilä, L&T Biowatti Oy, Seinäjoki, Finland E-mail: jh@nn.fi
  • Anttila, The Finnish Forest Research Institute, Joensuu, Finland E-mail: pa@nn.fi
article id 140, category Research article
Jussi Laurila, Risto Lauhanen. (2010). Moisture content of Norway spruce stump wood at clear cutting areas and roadside storage sites. Silva Fennica vol. 44 no. 3 article id 140. https://doi.org/10.14214/sf.140
Keywords: Picea abies; harvesting; bioenergy; moisture content; stump wood
Abstract | View details | Full text in PDF | Author Info
Norway spruce (Picea abies (L.) Karst.) stump wood is a potential source of bioenergy in Finland. The heating value of stump wood depends on, among other things, the moisture, carbon and ash content of the wood. In this study the moisture content of Norway spruce stump wood was examined immediately after harvesting at the clear cutting area and after different drying times at the roadside storage sites. Immediately after stump harvesting the average moisture content (wet basis) was 53%. The stump wood dried fairly fast during spring and summer. One month after stump harvesting, the average moisture content was about 31%. If the stump wood had dried well once, water absorption became very weak and the moisture content increased only slightly in the late autumn. Each spring and summer the moisture content of the stumps was lower than during the previous year. Annually the lowest moisture content was observed at the beginning of July and the highest at both the beginning and the end of the year. The moisture content of stump wood followed an upwards opening parabola over a one year period and was repeated each year. Three years after harvesting the heating value of the stump wood was still 5.241 MWh/ton. Overall, when harvesting took place in the spring or early summer, the stump wood was combustible after a one month drying period immediately after harvesting.
  • Laurila, Seinäjoki University of Applied Sciences, School of Agriculture and Forestry, FI-63700 Ähtäri, Finland E-mail: jussi.laurila@seamk.fi (email)
  • Lauhanen, Seinäjoki University of Applied Sciences, School of Agriculture and Forestry, FI-63700 Ähtäri, Finland E-mail: rl@nn.fi
article id 139, category Research article
Ulf Sikström, Curt Almqvist, Gunnar Jansson. (2010). Growth of Pinus sylvestris after the application of wood ash or P and K fertilizer to a peatland in southern Sweden. Silva Fennica vol. 44 no. 3 article id 139. https://doi.org/10.14214/sf.139
Keywords: fertilization; wood ash; nitrogen; ammonium nitrate; forest yield; needle element concentrations; potassium chloride; raw phosphate
Abstract | View details | Full text in PDF | Author Info
The effects of the application of wood ash and of fertilizer regimes including phosphorus (P) and potassium (K), with and without simultaneous addition of nitrogen (N), were investigated on a stand of Scots pine (Pinus sylvestris L.) saplings growing on a drained oligotrophic peatland site in southern Sweden. A randomized block design was used. Tree growth and concentrations of various elements in the needles were measured. The addition of similar doses of P (approx. 40 kg P ha–1) from different sources resulted in similar growth responses, amounting to 1.6–1.9 m3 ha–1 yr–1 of stem wood over the 26-year study. The P source was either wood ash (2500 kg d.w. ha–1) or PK-fertilizer (raw phosphate and potassium chloride). In response to several treatments there were both increased numbers of trees and increased growth of individual trees. The high PK-dose (40 kg P ha–1 and 80 kg K ha–1) appeared to result in a larger growth increase than the low dose (20 kg P ha–1 and 40 kg K ha–1). The N treatment had no additional effect on growth. In the control plots, tree growth was more or less negligible (0.04 m3 ha–1 yr–1). After almost 26 years, concentrations of P and K in the needles of treated plants were still higher than in the untreated control plants. Nevertheless, in spite of the elevated P concentration, P appears to limit the growth of Scots pine. In conclusion, after sufficient drainage of this type of peatland site, it is possible for a forest stand to develop to the pole stage if wood ash or PK-fertilizer is applied.
  • Sikström, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ulf.sikstrom@skogforsk.se (email)
  • Almqvist, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: ca@nn.se
  • Jansson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: gj@nn.se
article id 153, category Research article
Dirk Bieker, Steffen Rust. (2010). Non-destructive estimation of sapwood and heartwood width in Scots pine (Pinus sylvestris L.). Silva Fennica vol. 44 no. 2 article id 153. https://doi.org/10.14214/sf.153
Keywords: non-destructive testing; tomography; sapwood; pine
Abstract | View details | Full text in PDF | Author Info
Accurate estimates of the water conducting sapwood area are necessary to scale sapflow measurements to tree and stand level transpiration. We tested a non-destructive method, electric resistivity tomography (ERT), to estimate the area of conductive sapwood in 9 Pinus sylvestris L. trees in lower Saxony, Germany. Tomograms were compared to cross-sections stained with benzidine after harvesting. All tomograms displayed a distinct pattern of low resistivity at the stem perimeter and high resistivity in the stem centre with a steep increase in resistivity in between, assumed to indicate the transition from sapwood to heartwood. The tomograms showed a sapwood width 2 cm smaller than the staining method. This indicates that staining methods overestimate the amount of active sapwood because when heartwood is formed, moisture content decreases before extractive contents reach levels visible by staining. The ERT method is a new powerful method for the non-destructive estimation of sapwood and heartwood width.
  • Bieker, University of Applied Sciences and Arts, Faculty of Resource Management, Büsgenweg 1a, D-37077 Göttingen, Germany E-mail: db@nn.de
  • Rust, University of Applied Sciences and Arts, Faculty of Resource Management, Büsgenweg 1a, D-37077 Göttingen, Germany E-mail: rust@hawk-hhg.de (email)
article id 150, category Research article
Sini Eräjää, Panu Halme, Janne S. Kotiaho, Anni Markkanen, Tero Toivanen. (2010). The volume and composition of dead wood on traditional and forest fuel harvested clear-cuts. Silva Fennica vol. 44 no. 2 article id 150. https://doi.org/10.14214/sf.150
Keywords: dead wood; forest fuel harvesting; fine woody debris (FWD); clear-cut
Abstract | View details | Full text in PDF | Author Info
Logging residue and cut stumps are increasingly used as a renewable energy source known as forest fuel. Forest fuel harvesting obviously reduces the volume of dead wood and is likely to alter the dead wood composition, but the magnitude of the change is not known. Such information is important for the evaluation of the effects of forest fuel harvesting on biodiversity because a large proportion of forest dwelling species are directly dependent on dead wood. We measured the volume and characteristics of all dead wood units with a minimum diameter of 2 cm and a minimum length of 20 cm on 10 forest-fuel harvested and 10 traditional (control) clear-cuts. The total volume of dead wood at forest fuel harvested and control clear-cuts was 26.0 and 42.3 m3/ha, respectively. The volumes were much greater than expected suggesting that the volume of dead wood on clear-cuts has been underestimated in previous studies. Forest fuel harvested clear-cuts had 42% less branches and 81% less cut stumps than control clear-cuts but there were no differences in the volume of logs and pieces of logs, snags or roots. The volume of fine woody debris was negatively affected by forest fuel harvesting. We conclude that fine woody debris and cut stumps form a considerable resource on clear-cuts that is reduced by forest fuel harvesting. These components of dead wood have potential to be of importance in managed forests and thus deserve more attention in future biodiversity studies.
  • Eräjää, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: se@nn.fi
  • Halme, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: panu.halme@jyu.fi (email)
  • Kotiaho, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: jsk@nn.fi
  • Markkanen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: am@nn.fi
  • Toivanen, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: tt@nn.fi
article id 166, category Research article
Kim Pingoud, Johanna Pohjola, Lauri Valsta. (2010). Assessing the integrated climatic impacts of forestry and wood products. Silva Fennica vol. 44 no. 1 article id 166. https://doi.org/10.14214/sf.166
Keywords: carbon stocks; managed forests; silvicultural guidelines; harvested wood products; energy and material substitution; displacement of fossil carbon emissions
Abstract | View details | Full text in PDF | Author Info
Managed forests serve as a store of carbon (C) and a renewable source of energy and materials. By using forest products as substitutes for fossil fuels or non-renewable materials, emissions from fossil C sources can be displaced. The efficiency of emissions displacement depends on the product, its lifecycle and the fossil-fuel based reference system that is substituted. Forest management practices have an impact on C stocks in biomass and on the annual supply of products and their mix. There are trade-offs between sequestering C stocks in forests and the climatic benefits obtained by sustainable forest harvesting and using wood products to displace fossil C emissions. This article presents an integrated, steady-state analysis comparing various equilibrium states of managed forests and wood product pools that represent sustainable long-term forestry and wood-use strategies. Two climatic indicators are used: the combined C stock in forests and wood products and the fossil C emissions displaced annually by harvested wood products. The study indicates that long-term strategies could be available that are better according to both indicators than forestry practices based on the existing silvicultural guidelines in Finland. These strategies would involve increasing the basal area and prolonging rotations to produce more sawlogs. Further, the climate benefits appear to be highest in case the sawlog supply is directed to production of long-lived materials substituting for fossil-emission and energy intensive materials and recycled after their useful life to bioenergy.
  • Pingoud, VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo, Finland E-mail: kim.pingoud@vtt.fi (email)
  • Pohjola, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: jp@nn.fi
  • Valsta, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: lv@nn.fi
article id 460, category Research article
Hong Ling, Sandhya Samarasinghe, G. Don Kulasiri. (2009). Modelling variability in full-field displacement profiles and Poisson ratio of wood in compression using stochastic neural networks. Silva Fennica vol. 43 no. 5 article id 460. https://doi.org/10.14214/sf.460
Keywords: wood; digital image correlation; displacement profiles; variability; micro structure; stochastic neural networks; Poisson ratio
Abstract | View details | Full text in PDF | Author Info
Vertical and horizontal displacement profiles in compression parallel-to-grain in a 20 x 20 mm area (30 x 21 or 630 points) in the Tangential–Longitudinal (T–L) and Radial Longitudinal (R–L) sections of small wood columns were obtained from digital image correlation applied to simultaneously captured images of the two surfaces. These consisted of 21 displacement realisations of 30 points along the length of the specimen. They revealed considerable local variations. Stochastic neural networks were successfully developed to simulate trends and noise across and along a specimen in both displacements as well as Poisson ratios in T–L and R–L sections for two selected load levels of 20kN and 40kN. These networks specifically embed noise characteristics extracted from data to generate realistic displacement and Poisson ratio realisations with inherent variability. Models were successfully validated using independent data extracted based on bootstrapping method with high accuracy with R2 ranging from 0.79 to 0.91. The models were further validated successfully using a second approach involving Confidence Intervals generated from the data extracted from the models. Models and experimental results revealed that for 20kN load, both vertical and horizontal displacements in T–L section were less heterogeneous across the specimen (smaller vertical shearing and horizontal strain, respectively) than those in the R–L section. For the 40kN load, both displacement profiles in the T–L section were less noisy and more compact than those for the 20kN load indicating less heterogeneity due to compaction of structure. In the R–L section, larger vertical shearing and horizontal strains persisted at 40 kN load. Poisson ratio decreased with load and it was nonlinear in both sections but T–L section showed much less noise across the specimen than the R–L section.
  • Ling, Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand E-mail: hl@nn.nz
  • Samarasinghe, Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand E-mail: sandhya.samarasinghe@lincoln.ac.nz (email)
  • Kulasiri, Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand E-mail: gdk@nn.nz
article id 190, category Research article
Katri Luostarinen, Veikko Möttönen. (2009). Effect of felling season, storage and drying on colour of silver birch (Betula pendula) wood from four different growing sites. Silva Fennica vol. 43 no. 4 article id 190. https://doi.org/10.14214/sf.190
Keywords: birch; age; colour darkening; conventional drying; environmental factors; plantation; wood
Abstract | View details | Full text in PDF | Author Info
Darkening of birch wood during artificial drying is a significant problem regarding the use of its timber as raw material by the mechanical wood industry. In the future, an increasing proportion of birch timber will be obtained from plantation forests, which differ from natural forests in many respects. In this investigation sample boards of Betula pendula, both from naturally regenerated stands and plantations, were sawn into the dimensions used as raw material for parquet billets. Growing site, felling season, and storage of logs were taken into account as possible factors affecting wood colour changes during drying. The wood of birches from fertile plantations remained lighter-coloured during conventional drying than the wood of naturally regenerated birches from low- and medium-fertile stands. The reason may be the difference in tree age and growth rate between natural and planted stands. Thus, it could be beneficial to grow birch in fertile stands so that the trees reach log size as young as possible. The results of this study emphasise the good quality of the birch wood from planted stands compared to natural stands with regard to its colour.
  • Luostarinen, Faculty of Forest Sciences, University of Joensuu, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: katri.luostarinen@joensuu.fi (email)
  • Möttönen, Department of Mechanical Engineering, Lappeenranta University of Technology, P.O. Box 20, FI-53851 Lappeenranta, Finland E-mail: vm@nn.fi
article id 189, category Research article
Lars Rytter, Gunnar Jansson. (2009). Influence of pruning on wood characters in hybrid aspen. Silva Fennica vol. 43 no. 4 article id 189. https://doi.org/10.14214/sf.189
Keywords: Populus tremula P. tremuloides; cicatrisation; faultless wood; twig angle; twig diameter
Abstract | View details | Full text in PDF | Author Info
Fast-growing hybrid aspens (Populus tremula L. x P. tremuloides Michx.) are currently of great interest in Sweden since they can produce biomass at high rates and, at the same time, can be used to produce higher value wood products. This study focuses on the effects of pruning hybrid aspen to improve its wood quality. About 50% of the trees in the experimental stand were pruned by removing twigs, at heights up to 4 m, when they were 7–8 years old. Ten years later, 20 pruned and 20 unpruned trees, representing four clones, were randomly selected. Ten knots or twig/stem junctions, respectively, per tree were exposed for inspection using a chain saw and examined. The results revealed that pruned trees cicatrised the knots within about three years and thereafter produced substantial amounts of faultless wood. In contrast, unpruned trees (which had retained almost 80% of their twigs, often as dry twigs with bark pockets) had produced small uneven amounts of quality wood. Removal of twigs with acute angles and/or large diameters resulted in greater colour defects and rot in annual rings outside the pruning position, but the time of cicatrisation was not significantly affected. The results show that pruning can be used to enhance the wood quality of hybrid aspen over a short time period, and that pruning should be performed early during the rotation period when branches are small, in order to minimize discolouration and rot in the new annual rings.
  • Rytter, The Forestry Research Institute of Sweden (Skogforsk), Ekebo 2250, SE-26890 Svalöv E-mail: lars.rytter@skogforsk.se (email)
  • Jansson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala E-mail: gj@nn.se
article id 187, category Research article
Tobias Biechele, Leif Nutto, Gero Becker. (2009). Growth strain in Eucalyptus nitens at different stages of development. Silva Fennica vol. 43 no. 4 article id 187. https://doi.org/10.14214/sf.187
Keywords: growth stress; growth strain; Eucalyptus nitens; stages of development; sawnwood
Abstract | View details | Full text in PDF | Author Info
Eucalypts are renowned for their high growth stress levels. These stresses cause splitting, warping and dimensional instability when cutting, processing and drying the wood. In Chile, large Eucalyptus nitens plantations can be found, which, due to these problems, are scarcely utilised for solid wood products (veneer, sawn wood). This study aims to determine the factors influencing growth stress at different stages of tree’s development, and to identify whether the factors influencing growth stress change over time. In five stands of different ages, growth strain, as an indicator of growth stress, was measured at different tree heights with the single hole drilling method. The tree variables DBH, tree height, slenderness (height/diameter ratio) and crown parameters also were measured. A correlation analysis of tree variables and growth strains was undertaken. The results obtained indicate a high variability in growth strain values. It was concluded that growth strain is not correlated with a single growth parameter, but with a combination of factors that variously influence it at different ages and tree heights.
  • Biechele, University of Freiburg, Institute of Forest Utilisation and Work Science, Werthmannstr. 6, DE-79085 Freiburg, Germany E-mail: tobias.biechele@fobawi.uni-freiburg.de (email)
  • Nutto, University of Freiburg, Institute of Forest Utilisation and Work Science, Werthmannstr. 6, DE-79085 Freiburg, Germany E-mail: ln@nn.de
  • Becker, University of Freiburg, Institute of Forest Utilisation and Work Science, Werthmannstr. 6, DE-79085 Freiburg, Germany E-mail: gb@nn.de
article id 204, category Research article
Gaby Deckmyn, Bostjan Mali, Hojka Kraigher, Niko Torelli, Maarten Op de Beeck, Reinhart Ceulemans. (2009). Using the process-based stand model ANAFORE including Bayesian optimisation to predict wood quality and quantity and their uncertainty in Slovenian beech. Silva Fennica vol. 43 no. 3 article id 204. https://doi.org/10.14214/sf.204
Keywords: forest management; wood quality; Bayesian calibration; beech; forest model; mechanistic; red heart
Abstract | View details | Full text in PDF | Author Info
The purpose of this study was to expand an existing semi-mechanistic forest model, ANAFORE (ANAlysing Forest Ecosystems), to allow for the prediction of log quality and the accompanying uncertainty as influenced by climate and management. The forest stand is described as consisting of trees of different cohorts, either of the same or of different species (deciduous or coniferous). In addition to photosynthesis, transpiration, total growth and yield, the model simulates the daily evolution in vessel biomass and radius, parenchyma and branch development. From these data early and latewood biomass, wood tissue composition, knot formation and density are calculated. The new version presented here, includes the description of log quality, including red heart formation of beeches. A Bayesian optimisation routine for the species parameters was added to the stand model. From a given range of input parameters (prior), the model calculates an optimised range for the parameters (posterior) based on given output data, as well as an uncertainty on the predicted values. A case study was performed for Slovenian beech forests to illustrate the main model functioning and more in particular the simulation of the wood quality. The results indicate that the ANAFORE model is a useful tool for analyzing wood quality development and forest ecosystem functioning in response to management, climate and stand characteristics. However, the Bayesian optimization showed that the remaining uncertainty on the input parameters for the chosen stand was very large, due to the large number of input parameters in comparison to the limited stand data.
  • Deckmyn, Research Group Plant and Vegetation Ecology, University of Antwerpen, Universiteitsplein 1, 2610 Antwerpen, Belgium E-mail: gaby.deckmyn@ua.ac.be (email)
  • Mali, Slovenian Forestry Institute, Vecna pot 2, 1000 Ljubljana, Slovenia E-mail: bm@nn.si
  • Kraigher, Slovenian Forestry Institute, Vecna pot 2, 1000 Ljubljana, Slovenia E-mail: hk@nn.si
  • Torelli, Slovenian Forestry Institute, Vecna pot 2, 1000 Ljubljana, Slovenia E-mail: nt@nn.si
  • Op de Beeck, Research Group Plant and Vegetation Ecology, University of Antwerpen, Universiteitsplein 1, 2610 Antwerpen, Belgium E-mail: modb@nn.be
  • Ceulemans, Research Group Plant and Vegetation Ecology, University of Antwerpen, Universiteitsplein 1, 2610 Antwerpen, Belgium E-mail: rc@nn.be
article id 202, category Research article
Tuula Nuutinen, Antti Kilpeläinen, Hannu Hirvelä, Kari Härkönen, Veli-Pekka Ikonen, Reetta Lempinen, Heli Peltola, Lars Wilhelmsson, Seppo Kellomäki. (2009). Future wood and fibre sources – case North Karelia in eastern Finland. Silva Fennica vol. 43 no. 3 article id 202. https://doi.org/10.14214/sf.202
Keywords: National Forest Inventory; fibre length; wood density; proportion of latewood; forest scenario analysis
Abstract | View details | Full text in PDF | Author Info
Information on the potential wood supply is important for the wood industry. In this study, the future development of growing stock, cutting potential and wood properties corresponding to the regional scenario of North Karelian Forest Programme 2006–2010 was analysed. The simulations were performed by employing the Finnish MELA system together with the sample plot and tree data of the 9th Finnish National Forest Inventory (NFI9) as initial data for the simulations. Disc-based models for basic wood density, proportion of latewood and fibre length of Norway spruce and Scots pine in Sweden were calibrated and integrated into the MELA system. The wood properties at breast height of both harvested and standing trees were analysed in different strata (age, site type and cutting method) during the scenario period of 50 years (2002–2052). The average wood properties within the same strata varied only slightly over time. However, the results for different strata differed considerably. In general, wood density, fibre length and proportion of latewood increased, on average, as a function of tree age and along with a decrease in site fertility (excl. wood density and proportion of latewood in harvested Norway spruce in the first case and fibre length in the latter case for both species). For trees less than 80 years, properties in harvested trees were equal to or slightly greater than those of standing trees. The values for clear-cuttings were greater or equal to those of thinnings (excl. wood density and proportion of latewood in Norway spruce). The study demonstrates the value of model-based analyses utilising NFI tree measurements in regions that are considered to be sources of raw material.
  • Nuutinen, European Forest Institute, Torikatu 34, FI-80100 Joensuu, Finland E-mail: tuula.nuutinen@efi.int (email)
  • Kilpeläinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: ak@nn.fi
  • Hirvelä, Finnish Forest Research Institute, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: hh@nn.fi
  • Härkönen, Finnish Forest Research Institute, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: kh@nn.fi
  • Ikonen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: vpi@nn.fi
  • Lempinen, Finnish Forest Research Institute, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: rl@nn.fi
  • Peltola, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
  • Wilhelmsson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: lw@nn.fi
  • Kellomäki, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: sk@nn.fi
article id 201, category Research article
Rui Qi, Véronique Letort, Mengzhen Kang, Paul-Henry Cournède, Philippe de Reffye, Thierry Fourcaud. (2009). Application of the GreenLab model to simulate and optimize wood production and tree stability: a theoretical study. Silva Fennica vol. 43 no. 3 article id 201. https://doi.org/10.14214/sf.201
Keywords: wood quality; optimization; biomechanics; FSPM; Particle Swarm Optimization; source-sink dynamics; biomass allocation
Abstract | View details | Full text in PDF | Author Info
The GreenLab model was used to study the interaction between source-sink dynamics at the whole tree level, wood production and distribution within the stem, and tree mechanical stability through simulation and optimization. In this first promising numerical attempt, two GreenLab parameters were considered in order to maximize wood production: the sink strength for cambial growth and a coefficient that determines the way the biomass assigned to cambial growth is allocated to each metamer, through optimization and simulation respectively. The optimization procedure that has been used is based on a heuristic optimization algorithm called Particle Swarm Optimization (PSO). In the first part of the paper, wood production was maximized without considering the effect of wood distribution on tree mechanical stability. Contrary to common idea that increasing sink strength for cambial growth leads to increasing wood production, an optimal value can be found. The optimization results implied that an optimal source and sink balance should be considered to optimize wood production. In a further step, the mechanical stability of trees submitted to their self weight was taken into account based on simplified mechanical assumptions. Simulation results revealed that the allocation of wood at the stem base strongly influenced its global deformation. Such basic mechanical criterion can be an indicator of wood quality if we consider further the active biomechanical processes involved in tree gravitropic responses, e.g. formation of reaction wood.
  • Qi, Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Chatenay-Malabry, France; Institute of Automation, Chinese Academy of Sciences, LIAMA/NLPR, P.O.Box 2728, Beijing, China E-mail: qiruitree@gmail.com (email)
  • Letort, Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Chatenay-Malabry, France E-mail: vl@nn.fr
  • Kang, Institute of Automation, Chinese Academy of Sciences, LIAMA/NLPR, P.O.Box 2728, Beijing, China E-mail: mk@nn.cn
  • Cournède, Ecole Centrale Paris, Laboratory of Applied Mathematics, Grande Voie des Vignes, 92295 Chatenay-Malabry, France; INRIA saclay Ile-de-France, EPI Digiplant, Parc Orsay Université, 91893 Orsay cedex, France E-mail: phc@nn.fr
  • Reffye, INRIA saclay Ile-de-France, EPI Digiplant, Parc Orsay Université, 91893 Orsay cedex, France; CIRAD, UMR AMAP, Montpellier, F-34000 France E-mail: pdr@nn.fr
  • Fourcaud, CIRAD, UMR AMAP, Montpellier, F-34000 France E-mail: tf@nn.fr
article id 199, category Research article
R. Edward Thomas. (2009). Modeling the relationships among internal defect features and external Appalachian hardwood log defect indicators. Silva Fennica vol. 43 no. 3 article id 199. https://doi.org/10.14214/sf.199
Keywords: modeling; hardwood; log defects; surface scan
Abstract | View details | Full text in PDF | Author Info
As a hardwood tree grows and develops, surface defects such as branch stubs and wounds are overgrown. Evidence of these defects remain on the log surface for decades and in many instances for the life of the tree. As the tree grows the defect is encapsulated or grown over by new wood. During this process the appearance of the defect in the tree’s bark changes. The defect becomes flatter and its dimension changes. This progressional change in appearance is predictable, permitting the size and location of the internal defect to be reliably estimated. This paper concerns the development and analysis of models for the prediction of internal features. With the advent of surface scanning and external detection systems, the prediction of internal features promises to significantly improve the quality, yield, and value of sawn wood products.
  • Thomas, USDA Forest Service, 241 Mercer Springs Road, Princeton, WV 24740, USA E-mail: edthomas@gmail.com (email)
article id 195, category Research article
John R. Moore, Andrew J. Lyon, Gregory J. Searles, Leena E. Vihermaa. (2009). The effects of site and stand factors on the tree and wood quality of Sitka spruce growing in the United Kingdom. Silva Fennica vol. 43 no. 3 article id 195. https://doi.org/10.14214/sf.195
Keywords: wood quality; acoustics; timber properties; wood stiffness
Abstract | View details | Full text in PDF | Author Info
The extent and sources of variation in the wood quality of Sitka spruce (Picea sitchensis (Bong.) Carr.) were quantified using data collected from 64 stands in northern Britain. These stands were selected on the basis of elevation, latitude, longitude, yield class, initial spacing and the presence or absence of thinning. Dynamic modulus of elasticity (MOE) was calculated from measurements of stress wave velocity made on standing trees and qualitative descriptions were made of stem form. Dynamic MOE of individual trees ranged from 3.81 kN/mm2 up to 12.29 kN/mm2, with a mean of 7.71 kN/mm2. Approximately 55 percent of the variation in dynamic MOE was due to differences between individual trees within a site, while 35 percent was due to differences between sites. The remaining 10 percent was due to differences between the measurements made on opposite sides of each tree. Variation in dynamic MOE at the site level was significantly influenced by yield class, elevation as well as by a number of the interactions between these factors and latitude, longitude and initial spacing. A multiple regression model incorporating these variables was able to explain 45 percent of the variation in dynamic MOE. Ramicorn branches were the most commonly recorded defect (37.2% of all live trees), followed by stem scarring and basal sweep (6.9% and 6.3%, respectively). Dynamic MOE was not influenced by stem straightness (p = 0.10) which indicates the utility of stress wave velocity measurements for segregating Sitka spruce stands based on potential grade recovery.
  • Moore, Centre for Timber Engineering, Napier University, 10 Colinton Road, Edinburgh EH10 5DT, United Kingdom E-mail: j.moore@napier.ac.uk (email)
  • Lyon, Centre for Timber Engineering, Napier University, 10 Colinton Road, Edinburgh EH10 5DT, United Kingdom E-mail: ajl@nn.uk
  • Searles, Centre for Timber Engineering, Napier University, 10 Colinton Road, Edinburgh EH10 5DT, United Kingdom E-mail: gjs@nn.uk
  • Vihermaa, Department of Analytical and Environmental Chemistry, University of Glasgow, Glasgow, UK E-mail: lev@nn.uk
article id 194, category Research article
Ane Zubizarreta Gerendiain, Heli Peltola, Pertti Pulkkinen. (2009). Growth and wood property traits in narrow crowned Norway spruce (Picea abies f. pendula) clones grown in southern Finland. Silva Fennica vol. 43 no. 3 article id 194. https://doi.org/10.14214/sf.194
Keywords: fibre length; stem volume; height; diameter; wood density; earlywood; latewood
Abstract | View details | Full text in PDF | Author Info
We investigated the growth, yield, wood density traits and fibre properties in 13 narrow crowned Norway spruce (Picea abies f. pendula) clones grown at a spacing of 2 m x 1.5 m (about 3300 seedlings/ha) in a field trial established in 1988 in southern Finland on a forest soil. For comparison, we used 3 normal crowned Norway spruce (Picea abies (L.) Karst.) genetic entries grown as a mixture in the same trial representing southern Finnish breeding regions. We found that wood density traits and fibre properties showed, on average, lower phenotypic variation than growth and yield traits regardless of crown type. Narrow crowned clones also had, on average, lower stem volume and fibre length, but higher overall wood density. More over, the phenotypic correlations between studied growth and wood properties ranged, on average, from moderate (normal crown) to high (narrow crown). These results were opposite to previous findings for narrow and normal crowned genetic entries grown in narrower spacing (1 m x 1 m) in southern Finland. Thus, this indicates lower plasticity of narrow crowned clones to the increasing growing space compared to normal crowned ones, so, they should be grown at denser spacing in order to fully utilise its space efficiency capacity. However, this field trial was established as a mixture of normal and narrow crown trees, so that 90% of genetic entries were narrow crowned ones, and therefore the crown competition would be much higher for normal crowned trees when the whole trial would consist of that entry alone. In the latter case, we could expect significantly lower productivity of normal crowned genetic entries with this spacing.
  • Zubizarreta Gerendiain, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: ane.zubizarreta@joensuu.fi (email)
  • Peltola, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, FI-12600 Läyliäinen, Finland E-mail: pp@nn.fi
article id 193, category Research article
Jaume Gort, Ane Zubizarreta Gerendiain, Heli Peltola, Pertti Pulkkinen, Johanna Routa, Raimo Jaatinen. (2009). Differences in fibre properties in Scots pine (Pinus sylvestris L.) genetic entries grown at different spacing and sites. Silva Fennica vol. 43 no. 3 article id 193. https://doi.org/10.14214/sf.193
Keywords: fibre length; fibre width; genetic entry; growth; wood density; coarseness; spacing
Abstract | View details | Full text in PDF | Author Info
In forest breeding, stem volume growth and sawn timber quality indicators have been used as the most important selection traits for Scots pine, whereas less attention has been given to characteristics such as fibre properties. In the above context, we investigated the differences in fibre properties (i.e. fibre length, fibre width and coarseness) in 20 year old Scots pine (Pinus sylvestris L.) genetic entries as affected by spacing and site, but also the phenotypic correlations between fibre properties, yield and wood density. The study was based on materials harvested from 10 genetic entries grown in a spacing trial (site 1) in central Finland, with a current stand density of 2000 (spacing 1), 2000–2500 (spacing 2) and 4000 trees/ha (spacing 3). In order to study the effects of site, we harvested additional material (4 of 7 genetic entries same as on site 1) from a trial located in southern Finland with a corresponding stand density of 2000 trees/ha (site 2). On site 1, spacing 1 and 3, all average values for analysed fibre properties were similar. In spacing 2 average values were slightly higher. On site 2, the average values for different fibre properties were similar compared to the corresponding spacing 1 on site 1. Spacing affected (p < 0.05) all average fibre properties on site 1; as did also site, when comparing same genetic entries grown on both sites. Regardless of spacing and site, the phenotypic correlations between average fibre length, fibre width and coarseness showed, on average, moderate to strong correlation (p < 0.05). Fibre width showed, in general, low and positive phenotypic correlation with diameter at breast height, stem volume and wood density on site 1. However, as a whole, the ranking of genetic entries changed depending on the trait and spacing considered. Thus, no overall ranking between genetic entries was possible.
  • Gort, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jaume.gort@joensuu.fi (email)
  • Zubizarreta Gerendiain, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: azg@nn.fi
  • Peltola, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: hp@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie E-mail: pp@nn.fi
  • Routa, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jr@nn.fi
  • Jaatinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie E-mail: rj@nn.fi
article id 192, category Research article
Heli Peltola, Jaume Gort, Pertti Pulkkinen, Ane Zubizarreta Gerendiain, Jouni Karppinen, Veli-Pekka Ikonen. (2009). Differences in growth and wood density traits in Scots pine (Pinus sylvestris L.) genetic entries grown at different spacing and sites. Silva Fennica vol. 43 no. 3 article id 192. https://doi.org/10.14214/sf.192
Keywords: genetic entry; stem volume; height; diameter; wood property traits; phenotypic correlation
Abstract | View details | Full text in PDF | Author Info
In forest breeding, stem volume has typically taken as the most important selection trait, whereas less attention has been given to wood density traits. In this work, we investigated the effects of spacing and genetic entry on the growth, yield and wood density traits in 20 year old Scots pines (Pinus sylvestris L.) based on 10 genetic entries harvested from a spacing trial (stand density range 2000–4000 trees/ha) in central Finland. In order to study also the site effects, we harvested additional material from a trial located in southern Finland (stand density of 2000 trees/ha). Compared to growth and yield properties, wood density traits showed a lower phenotypic variation. Phenotypic correlations among different traits were negative, and mostly moderate to high, suggesting that selection for one trait would simultaneously affect the others. In addition, moderate to strong phenotypic correlations were found among different wood density traits. Stem volume (V) and breast height diameter (DBH) were the largest in widest spacing, whereas in the densest one tree height (H) and latewood percentage were the highest. Genetic entry affected H and wood density traits regardless of spacing. When comparing two sites (with same stand density), genetic entry affected H, whereas site affected DBH and wood density traits. Ranking between genetic entries changed depending on the trait, spacing or site considered. Therefore, no overall ranking was possible. However, we could identify genetic entries having a high V and a relatively high wood density, showing potential for future forest regeneration material.
  • Peltola, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: heli.peltola@joensuu.fi (email)
  • Gort, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jg@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Karkkilantie 247, FI-12600 Läyliäinen, Finland E-mail: pp@nn.fi
  • Zubizarreta Gerendiain, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: azg@nn.fi
  • Karppinen, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: jk@nn.fi
  • Ikonen, University of Joensuu, Faculty of Forest Sciences, FI-80101 Joensuu, Finland E-mail: vpi@nn.fi
article id 191, category Research article
Katri Luostarinen, Noora Huotari, Eila Tillman-Sutela. (2009). Effect of regeneration method on growth, wood density and fibre properties of downy birch (Betula pubescens Ehrh.). Silva Fennica vol. 43 no. 3 article id 191. https://doi.org/10.14214/sf.191
Keywords: coppice; fibre length; fibre width; regeneration methods; wood properties
Abstract | View details | Full text in PDF | Author Info
Short rotation tree stands, established by coppicing, are nowadays used mainly for energy purposes in Fennoscandia, but their usage for pulp raw material may increase in the future. Downy birch (Betula pubescens), which is commonly used for pulp production in boreal zone, has good sprouting capacity. However, it is not known if the fibre properties of sprout-originated downy birches differ from those of seed-originated ones. Therefore, fibre length and width of sprout- and seed-originated downy birches grown on fertile soil were measured at a stand age of 25 years. Additionally annual ring width, stem height and diameter, and wood density were studied to compare the growth and wood properties of sprout- and seed-originated birches. Annual rings were slightly wider in sprout- than in seed-originated birches, whereas no differences were observed in wood density. Fibres, too, were slightly longer and wider in sprout- than in seed-originated trees. Still these minor differences observed here are hardly significant for the industries using birch wood. Consequently downy birch wood from coppiced stands is well suited for pulp. The advantages of coppice, i.e. rapidity and low costs of establishment, productivity, and the ability of downy birch to grow on untypical forest sites, may even increase the importance of the wood coming from coppiced birch stands in the future.
  • Luostarinen, Faculty of Forest Sciences, University of Joensuu, P.O. Box 111, FI-80101, Joensuu, Finland E-mail: katri.luostarinen@joensuu.fi (email)
  • Huotari, Finnish Forest Research Institute, Muhos Research Unit, Kirkkosaarentie, FI-91500 Muhos, Finland E-mail: nh@nn.fi
  • Tillman-Sutela, Finnish Forest Research Institute, Muhos Research Unit, Kirkkosaarentie, FI-91500 Muhos, Finland E-mail: ets@nn.fi
article id 212, category Research article
Sandhya Samarasinghe. (2009). Exploration of fracture dynamics properties and predicting fracture toughness of individual wood beams using neural networks. Silva Fennica vol. 43 no. 2 article id 212. https://doi.org/10.14214/sf.212
Keywords: Pinus radiata; wood properties; cracks; initiation; New Zealand; peak stress; speed; video imaging
Abstract | View details | Full text in PDF | Author Info
In this study, the time to crack initiation (Tinit), duration of crack propagation (Tfrac), crack initiation stress, peak stress as well as crack speed and fracture toughness were investigated for three Rates of Loading (ROL) and four sizes of notched wood beams using high-speed video imaging and neural networks. Tinit was consistent for all volumes and the average Tinit was nonlinearly related to volume and ROL. For the smallest ROL, there was a distinct volume effect on Tinit and the effect was negligble at the largest ROL. However, the stress at crack initiation was not consistent. Contrasting these, Tfrac for all volumes appeared to be highly variable but the peak stress carried prior to catastrophic failure was consistent. The crack propagation was a wave phenomenon with positive and negative (crack closure) speeds that varied with the ROL. As accurate estimation of crack initiation load (or stress) and its relationship to peak load (or stress) is important for determining fracture toughness, Artificial Neural Networks (ANN) models were developed for predicting them from volume, Young’s modulus, face and grain angles, density, moisture content and ROL. Models for crack initiation load and peak load showed much higher predictive power than those for the stresses with correlation coefficients of 0.85 and 0.97, respectively, between the actual and predicted loads. Neural networks were also developed for predicting fracture toughness of individual wood specimens and the best model produced a statistically significant correlation of 0.813 between the predicted and actual fracture toughness on a validation dataset. The inputs captured 62% of variability of fracture toughness. Volume and Young’s modulus were the top two contributing variables with others providing lesser contributions.
  • Samarasinghe, Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Canterbury, New Zealand E-mail: sandhya.samarasinghe@lincoln.ac.nz (email)
article id 464, category Research article
Christian Kanzian, Franz Holzleitner, Karl Stampfer, Sarah Ashton. (2009). Regional energy wood logistics – optimizing local fuel supply. Silva Fennica vol. 43 no. 1 article id 464. https://doi.org/10.14214/sf.464
Keywords: logistics; energy wood; transport optimization; GIS
Abstract | View details | Full text in PDF | Author Info
The promotion of electric energy production from solid biomass by the Austrian government has lead to a boom in the construction of new combined heat and power plants. The current total demand for wood chips in the research area for energy purposes is 70 400 m3 of loose volume chips per year. The expected increase in demand due to these new plants is more than 4 times greater than current demand: up to 302 700 m3 of loose volume per year. Even if the energy wood feedstock potential is satisfactory, the design of the supply chain is still unresolved. The aim of this study is to give decision-makers a base for further development. To accomplish this, we designed and tested four different supply scenarios: one for 9 plants and one for 16 plants. The scenarios were developed using a combination of geographic information systems (GIS) and linear programming methods. The results indicate that direct transport of solid fuel wood as round wood and chipping at the plant is the cheapest supply system with a resulting cost of 5.6–6.6 EUR/m3 loose. Using harvesting residues can only be recommended for large plants because of poor fuel quality. In this case, residues would be chipped at or near the landing, piled and transported via self-loading trucks at a cost between 8.4 and 9.1 EUR/m3 loose. In order to meet increasing demand and to ensure a continuous supply, especially during the winter and spring seasons it is necessary to optimize the supply chain by including storage terminals. However, using terminals and increased demand both lead to higher logistical costs. For example, if the total volume is handled via terminals, the average supply costs including storage will increase by 26%. Higher demand increases the costs by 24%.
  • Kanzian, University of Applied Life Sciences Vienna, Institute of Forest Engineering, Peter Jordan Strasse 82, A-1190 Vienna, Austria E-mail: christian.kanzian@boku.ac.at (email)
  • Holzleitner, University of Applied Life Sciences Vienna, Institute of Forest Engineering, Peter Jordan Strasse 82, A-1190 Vienna, Austria E-mail: fh@nn.at
  • Stampfer, University of Applied Life Sciences Vienna, Institute of Forest Engineering, Peter Jordan Strasse 82, A-1190 Vienna, Austria E-mail: ks@nn.at
  • Ashton, Southern Regional Extension Forestry, Forestry Bldg. 4-420, University of Georgia, Athens, GA 30602, USA E-mail: sa@nn.us
article id 221, category Research article
Glen Murphy, Rod Brownlie, Mark Kimberley, Peter Beets. (2009). Impacts of forest harvesting related soil disturbance on end-of-rotation wood quality and quantity in a New Zealand radiata pine forest. Silva Fennica vol. 43 no. 1 article id 221. https://doi.org/10.14214/sf.221
Keywords: Pinus radiata; harvesting; compaction; wood density; tree growth; stiffness; litter removal; nitrogen deficiency
Abstract | View details | Full text in PDF | Author Info
The long-term effect of soil disturbance (litter removal, topsoil removal and compaction) from forest harvesting on wood quality and quantity of second-rotation Pinus radiata growing on a clay loam soil, was assessed at the end the rotation, 26 years after planting. Relative to Control plots, average tree and stand total volume at rotation end was not significantly affected by litter removal and nil or light compaction, but was significantly reduced by 28% by litter and topsoil removal and moderate subsoil compaction, and further reduced by 38% by heavy compaction. Wood density at breast height in the inner rings of trees in the most disturbed treatments was elevated by up to 30 kg m–3. This occurred because these treatments were more N deficient as reflected by foliar N levels during the first 11 years of growth relative to the Control. However, no treatment differences in wood density were evident in outer rings, and by rotation age overall mean density did not differ significantly between treatments. Neither acoustic velocity of standing trees, nor acoustic velocity of logs, was significantly affected by soil disturbance, indicating that stiffness of lumber cut from trees in the trial was likely to be similar for all treatments. Economic impacts of soil disturbance and compaction on this soil type will therefore result largely from the considerable negative impacts on final tree size, with little or no compensation from improved wood properties.
  • Murphy, Forest Engineering, Resources and Management Department, Oregon State University, Corvallis, Oregon, USA E-mail: glen.murphy@oregonstate.edu (email)
  • Brownlie, Scion Research, Rotorua, New Zealand E-mail: rb@nn.nz
  • Kimberley, Scion Research, Rotorua, New Zealand E-mail: mk@nn.nz
  • Beets, Scion Research, Rotorua, New Zealand E-mail: pb@nn.nz
article id 220, category Research article
Jani Heikkilä, Matti Sirén, Anssi Ahtikoski, Jari Hynynen, Tiina Sauvula, Mika Lehtonen. (2009). Energy wood thinning as a part of stand management of Scots pine and Norway spruce. Silva Fennica vol. 43 no. 1 article id 220. https://doi.org/10.14214/sf.220
Keywords: energy wood thinning; stand management; MOTTI simulator
Abstract | View details | Full text in PDF | Author Info
The effects of combined production of industrial and energy wood on yield and harvesting incomes, as well as the feasibility of energy wood procurement, were studied. Data for 22 Scots pine (Pinus sylvestris L.) and 21 Norway spruce (Picea abies (L.) Karst.) juvenile stands in Central and Southern Finland were used to compare six combined production regimes to conventional industrial wood production. The study was based on simulations made by the MOTTI stand simulator, which produces growth predictions for alternative management regimes under various site and climatic conditions. The combined production regimes included precommercial thinning at 4–8 m dominant height to a density of 3000–4000 stems ha–1 and energy wood harvesting at 8, 10 or 12 m dominant height. Combined production did not decrease the total yield of industrial wood during the rotation period. Differences in the mean annual increment (MAI) were small, and the rotation periods varied only slightly between the alternatives. Combined production regime can be feasible for a forest owner if the price of energy wood is 3–5 EUR m–3 in pine stands, and 8–9 EUR m–3 in spruce stands. Energy wood procurement was not economically viable at the current energy price (12 EUR MWh–1) without state subsidies. Without subsidies a 15 EUR MWh–1 energy price would be needed. Our results imply that the combined production of industrial and energy wood could be a feasible stand management alternative.
  • Heikkilä, L&T Biowatti Oy, P.O. Box 738, FI-60101 Seinäjoki, Finland E-mail: jani.heikkila@biowatti.fi (email)
  • Sirén, Finnish Forest Research Institute, Vantaa Research Unit, P.O.Box 18, FI-01301 Vantaa, Finland E-mail: ms@nn.fi
  • Ahtikoski, Finnish Forest Research Institute, Rovaniemi Research Unit, P.O.Box 16, FI-96301 Rovaniemi, Finland E-mail: aa@nn.fi
  • Hynynen, Finnish Forest Research Institute, Vantaa Research Unit, P.O.Box 18, FI-01301 Vantaa, Finland E-mail: jh@nn.fi
  • Sauvula, Seinäjoki University of Applied Sciences, School of Agriculture and Forestry, Tuomarniementie 55, FI-63700 Ähtäri, Finland E-mail: ts@nn.fi
  • Lehtonen, Finnish Forest Research Institute, Vantaa Research Unit, P.O.Box 18, FI-01301 Vantaa, Finland E-mail: ml@nn.fi
article id 216, category Research article
Juha Siitonen, Jenni Hottola, Auli Immonen. (2009). Differences in stand characteristics between brook-side key habitats and managed forests in southern Finland. Silva Fennica vol. 43 no. 1 article id 216. https://doi.org/10.14214/sf.216
Keywords: dead wood; woodland key habitats; stand structure; CWD; WKH; Forest Act
Abstract | View details | Full text in PDF | Author Info
Preservation of small habitat patches termed as “woodland key habitats” or “especially important habitats” in the Finnish Forest Act has become an integral part of biodiversity-oriented forest management. Forest Act habitats belong to particular habitat types defined in the act, and they are supposed to have natural-like stand characteristics. However, very little is known about the actual stand structure in the designated habitats. Our aim was to compare stand characteristics between brook-side key habitats and comparable managed forests as controls. Seven study areas were selected from four regions across southern Finland. Within each study area ten key habitats and ten controls (140 stands) were randomly selected. Living and dead trees and cut stumps were measured in each stand within a 0.2 ha plot. The average degree of previous cutting was significantly lower whereas the volume of dead wood, volume of deciduous trees, and stand diversity were each significantly higher in key habitats than controls. The average volume of dead wood was 11.7 m3 ha–1 in key habitats and 6.5 m3 ha–1 in controls. However, there was considerable variation among individual stands, and a large part of key habitats could not be distinguished from randomly selected control stands with respect to stand characteristics. The preservation of natural brook channels with their immediate surroundings is undoubtedly important for maintaining aquatic and semiaquatic biodiversity. Nevertheless, when complementing the forest conservation network in the future, main emphasis in selecting potentially valuable stands should be placed on important structural features such as dead wood and old trees.
  • Siitonen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: juha.siitonen@metla.fi (email)
  • Hottola, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: jh@nn.fi
  • Immonen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ai@nn.fi
article id 227, category Research article
Ola Lindroos. (2008). The effects of increased mechanization on time consumption in small-scale firewood processing. Silva Fennica vol. 42 no. 5 article id 227. https://doi.org/10.14214/sf.227
Keywords: comparative time study; fuelwood; blade saw; wedge splitter; processor; senior worker; operator effects
Abstract | View details | Full text in PDF | Author Info
Firewood, which is mainly processed by the consumer, is still an important source of energy for heating houses in industrialised countries. Possibilities to compare the mechanization’s impact on efficiency of firewood processing are limited, due to variations between working conditions in previous studies. Therefore, the objective was to compare time consumption for two small-scale firewood processing systems with different levels of mechanisation under identical conditions. The systems were tested on two classes of wood: one with a homogeneous and medium-sized diameter of logs and one with a mixture of small and large-diameter-logs. Differences in time consumption were analysed for correlations with physical workloads, deviations to routine operations, operator influences and operator perceptions. Twelve operators (60–79 years old) were studied and they showed large variation in time consumption. However, the within-operator time consumption patterns were consistent. In other words, operators all responded similarly to the different combinations of systems and wood classes, but at different absolute levels. The time required to process a unit volume of wood was 25–33% lower when the more highly mechanised system was used, and the time required was 13–22% lower for the homogeneous wood class. Physical work load, deviations and perceptions of the work varied between operators, but were weakly correlated with time consumption. The results’ implications for analyses of investments in equipment for firewood-processing for self-sufficiency purposes are discussed.
  • Lindroos, Swedish University of Agricultural Sciences, Department of Forest Resource Management, SE-901 83 Umeå, Sweden E-mail: ola.lindroos@srh.slu.se (email)
article id 225, category Research article
Johan Bergh, Urban Nilsson, Harald Grip, Per-Ola Hedwall, Tomas Lundmark. (2008). Effects of frequency of fertilisation on production, foliar chemistry and nutrient leaching in young Norway spruce stands in Sweden. Silva Fennica vol. 42 no. 5 article id 225. https://doi.org/10.14214/sf.225
Keywords: boreal; sludge; wood-ash; N; P; K
Abstract | View details | Full text in PDF | Author Info
There is a great need to increase the production in Swedish forests to meet future demand from the forest industry and the bio-energy sector. One option to increase the production is to supply nutrients to young stands of Norway spruce. For the practical application it is important to develop and optimise fertilisation regimes in terms of production, economy and leaching of nutrients. The frequency of fertilisation is one important variable in the fertilisation regime, and this study aimed to study effects of different fertilisation frequencies on production and leaching of nitrogen. In 2001, five field experiments were established in southern, central and northern Sweden. Young stands of Norway spruce were fertilised every year, every second year and every third year. In addition, fertilisation with sludge pellets and wood-ash combined with nitrogen was investigated. The current annual increment after five years of treatment was significantly larger in fertilised than in unfertilised treatments. The difference in production between fertilisation every year and every second year was insignificant, while fertilisation every third year resulted in lower production. Sludge pellets and wood-ash fertilisation gave significantly lower production than fertilisation every second year even though approximately the same amount of nitrogen was applied. There was relatively little leaching of nitrate to ground water in all treatments; 0.6–1 kg N ha–1 a–1 from plots with fertilisation every year or every second year; and 2.7 kg N ha–1 a–1 from plots with fertilisation every third year. Most of the leaching was after the first fertilisation, in all treatments at all sites.
  • Bergh, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: johan.bergh@ess.slu.se (email)
  • Nilsson, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: un@nn.se
  • Grip, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: hg@nn.se
  • Hedwall, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: poh@nn.se
  • Lundmark, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: tl@nn.se
article id 248, category Research article
Tuula Jyske, Harri Mäkinen, Pekka Saranpää. (2008). Wood density within Norway spruce stems. Silva Fennica vol. 42 no. 3 article id 248. https://doi.org/10.14214/sf.248
Keywords: Picea abies; wood density; inter-ring variation; intra-ring variation; maturation
Abstract | View details | Full text in PDF | Author Info
We studied the variation in average wood density of annual rings, earlywood density, and latewood density in addition to ring width and latewood percentage within Norway spruce (Picea abies (L.) Karst.) stems from the pith to the bark, and from the stem base towards the stem apex. Moreover, the variation in wood density within annual rings was studied at the different heights and radial positions in the stem. The material consisted of 85 trees from central and south-eastern Finland. Variation between the annual rings accounted for 11–27% of the total variation in wood density. Only small differences (3–6%) in wood density were found between different heights in the stem. The largest (49–80%) variation in wood density was found within the annual rings. The difference in wood density between earlywood and latewood was smaller in the rings near the pith than in the outer rings. The increasing wood density from the pith outwards was related to increasing latewood density and latewood percentage, whereas the earlywood density increased only slightly from the pith outwards. In a given cambial age (i.e., given rings from the pith), the average wood density of annual rings increased with increasing stem height. In contrast, in the rings formed in the same calendar years (i.e., given rings from the bark), the average wood density of annual rings decreased with increasing stem height. The results of this study verify our knowledge of wood density variation and can further contribute to creating models to predict wood density.
  • Jyske, The Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: tuula.jyske@metla.fi (email)
  • Mäkinen, The Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: hm@nn.fi
  • Saranpää, The Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ps@nn.fi
article id 247, category Research article
Ane Zubizarreta Gerendiain, Heli Peltola, Pertti Pulkkinen, Veli-Pekka Ikonen, Raimo Jaatinen. (2008). Differences in growth and wood properties between narrow and normal crowned types of Norway spruce grown at narrow spacing in Southern Finland. Silva Fennica vol. 42 no. 3 article id 247. https://doi.org/10.14214/sf.247
Keywords: fibre length; stem volume; height; diameter; wood density; earlywood; latewood
Abstract | View details | Full text in PDF | Author Info
In recent years there has been increased interest in the so called narrow crowned Norway spruce (Picea abies f. pendula), which is a rare mutant of Norway spruce (Picea abies (L.) Karsten), as a suitable wood raw material source for pulp and paper production. This is because it is less sensitive to competition than the normal crowned Norway spruce, and thus, could be more productive especially at dense spacing. In the above context, we investigated how the growth and yield (such as height, diameter, stem volume and ring width) in addition to wood density traits and fibre properties (such as wood density, fibre length and width, cell wall thickness and fibre coarseness) were affected in trees from 9 full-sib families representing narrow crowned Norway spruce grown at narrow spacing of 1 m 1 m in Southern Finland. For comparison, we used normal crowned Norway spruce trees from 6 breeding regions. We found that, compared to growth and yield traits, wood density traits and fibre properties showed, on average, lower phenotypic variations. In addition, these variations were smaller for narrow crowned families than for normal crowned genetic entries. Narrow crowned families also showed, on average, higher growth and yield and fibre length, but lower wood density. Moreover, the phenotypic correlations between growth, yield, wood density traits and fibre properties, ranged, on average, from moderate (narrow crowned) to high (normal crowned). As a whole, the growth and wood properties of narrow crowned families were found to be less sensitive to tree competition than the normal crowned genetic entries used as a comparison.
  • Zubizarreta Gerendiain, University of Joensuu, Faculty of Forest Sciences, Joensuu, Finland E-mail: ane.zubizarreta@joensuu.fi (email)
  • Peltola, University of Joensuu, Faculty of Forest Sciences, Joensuu, Finland E-mail: hp@nn.fi
  • Pulkkinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Läyliäinen, Finland E-mail: pp@nn.fi
  • Ikonen, University of Joensuu, Faculty of Forest Sciences, Joensuu, Finland E-mail: vpi@nn.fi
  • Jaatinen, Finnish Forest Research Institute, Haapastensyrjä Breeding Station, Läyliäinen, Finland E-mail: rj@nn.fi
article id 259, category Research article
Jani Laturi, Jarmo Mikkola, Jussi Uusivuori. (2008). Carbon reservoirs in wood products-in-use in Finland: current sinks and scenarios until 2050. Silva Fennica vol. 42 no. 2 article id 259. https://doi.org/10.14214/sf.259
Keywords: climate change; wood products; carbon pool; present value; decay function
Abstract | View details | Full text in PDF | Author Info
This study addresses the question of how much carbon will be sequestered in wood products during the coming decades in Finland. Using sawnwood and other wood material consumption data since the 1950s and inventory data of carbon reservoirs of wood products in the Finnish construction and civil engineering sector, we first derive estimates for the carbon reservoirs in wood products-in-use in that sector. We then extend the estimate to include all wood products-in-use. We find that the carbon pool of wood products in the Finnish construction and civil engineering sector grew by about 12% since an inventory for 2000, and that the overall estimate for carbon reservoirs of Finnish wood products in 2004 was 26.6 million tons of carbon. In building the scenarios until 2050, econometric time series models accounting for the relationship between wood material consumption and the development of GDP were used. The results indicate that the range of carbon reservoirs of wood products in Finland will be 39.6–64.2 million tons of carbon in the year 2050. The impacts of different forms of the decay function on the time-path of a carbon sink and its value in wood products were also studied. When a logistic decay pattern is used, the discounted value of the predicted carbon sink of wood products in Finland is between EUR850 and EUR1380 million – at the price level of EUR15/CO2 ton – as opposed to 440–900 million euros, if a geometric decay pattern is used.
  • Laturi, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: jani.laturi@metla.fi (email)
  • Mikkola, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: jm@nn.fi
  • Uusivuori, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ju@nn.fi
article id 257, category Research article
Nadir Ayrilmis. (2008). Effect of compression wood on dimensional stability of medium density fiberboard. Silva Fennica vol. 42 no. 2 article id 257. https://doi.org/10.14214/sf.257
Keywords: compression wood; linear expansion; linear contraction; thickness swelling; thickness shrinkage; medium density fiberboard; dimensional stability
Abstract | View details | Full text in PDF | Author Info
This study evaluated the effect of compression wood on dimensional stability of medium density fiberboards (MDF) manufactured from fiber furnishes of pine (Pinus nigra Arnold var. pallasiana) containing compression wood. Two panel types were manufactured from two different compression wood (CW) portion / normal wood (NW) portions in the furnish, 75/25 and 10/90, respectively. Linear and thickness variations of the panels exposed to various relative humidites at 20 °C, linear expansion/contraction and thickness swelling/shrinkage, were measured according to the procedures defined by DIN EN 318 (2005) standard test method. Panels made from fiber furnish containing 75% the CW had higher linear expansion and linear contraction values with an average value of 0.286% and 0.247% than those of panels made from fiber furnish containing 10% the CW with an average value of 0.184% and 0.152%, respectively. As for thickness swelling and thickness shrinkage properties, panels made from fiber furnish containing 75% the CW had the thickness swelling and thickness shrinkage values with an average of 5.042% and 4.402% while panels made from fiber furnish containing 10% the CW had the values with 3.621% and 2.861%, respectively. Consequently, based on the findings obtained from this study, expansion and swelling properties of the MDF panels were negatively affected by compression wood increase.
  • Ayrilmis, University of Istanbul, Faculty of Forestry, Department of Wood Mechanics and Technology, Bahcekoy, TR-34473 Istanbul, Turkey E-mail: nadiray@istanbul.edu.tr (email)
article id 256, category Research article
Juha Laitila. (2008). Harvesting technology and the cost of fuel chips from early thinnings. Silva Fennica vol. 42 no. 2 article id 256. https://doi.org/10.14214/sf.256
Keywords: productivity; harvesting; logging; energy wood; early thinnings; costs
Abstract | View details | Full text in PDF | Author Info
This study compared and analyzed the procurement cost of whole tree chips when using supply chains based on comminution at the roadside landing or at the terminal. It also identified the bottlenecks of the most common logging systems used in Finland. The study was done by using existing and published productivity parameters and models. The procurement cost calculations were made for a stand where the forwarding distance was 200 metres, removal of whole trees was 60 m per hectare and the area of the stand was 2.0 hectares. The average size of the removed whole trees was 30 litres. The direct transport distance from the stand to the terminal or to the end use facility was 40 km while the secondary distance from the terminal to the end use facility was 10 km. A stumpage price for the harvested raw material was not included in this study. According to the study the cost of whole trees chips were 31.9–41.6 euros/m at the plant, or 14.9–19.4 euros/MWh when the moisture content of chips was estimated to be 40%. The two-machine system was found to be the most cost competitive logging system in pre-commercial thinnings thanks to both efficient cutting and, especially, forwarding work. In the manual worker based logging, the costs of felling bunching were the same as the mechanised system, whereas in forwarding the costs were almost double. Using the harwarder system the logging costs were found to be the highest, but in the larger tree volumes and removals the costs were almost equal to the manual worker based logging. The supply chain based on chipping at the roadside landing was more cost efficient compared to the chipping at the terminal system. The lower comminution cost at the terminal was not enough to cover the higher transportation cost of unprocessed material to the terminal, handling cost of chips at the terminal or the delivery cost to the end use facility.
  • Laitila, Finnish Forest Research Institute, Joensuu Research Unit, Joensuu, Finland E-mail: juha.laitila@metla.fi (email)
article id 254, category Research article
Johanna Joensuu, Kari Heliövaara, Eino Savolainen. (2008). Risk of bark beetle (Coleoptera, Scolytidae) damage in a spruce forest restoration area in central Finland. Silva Fennica vol. 42 no. 2 article id 254. https://doi.org/10.14214/sf.254
Keywords: biodiversity; dead wood; damage; forest pests; forest restoration
Abstract | View details | Full text in PDF | Author Info
A beetle inventory using window traps was performed to examine the effect of forest restoration by artificial addition of dead wood on the abundance of beetles and to evaluate the risk of bark beetle damage in a forest restoration area. The number of beetle families was slightly increased, but no consistent differences were found in the abundance of families containing saproxylic Coleoptera between the restoration and control plots. The abundance and species number of bark beetles and longhorn beetles were significantly higher on the restoration plots. Ips typographus and Pityogenes chalcographus increased only slightly in abundance. In the regression models produced, the abundance of bark beetles was best explained by the volume of recently dead wood. However, the bark beetle species whose abundance increased most were secondary and the material also suggests an increase in the abundance of bark beetles’ natural enemies. The risk of bark beetle damage in the area is thus considered insignificant.
  • Joensuu, Dept. of Forest Ecology, University of Helsinki, Finland E-mail: johanna.joensuu@metsanhoitajat.fi (email)
  • Heliövaara, Dept. of Forest Ecology, University of Helsinki, Finland E-mail: kh@nn.fi
  • Savolainen, Kuopio Natural History Museum, Kuopio, Finland E-mail: es@nn.fi
article id 250, category Research article
Saara Lilja-Rothsten, Michelle de Chantal, Chris Peterson, Timo Kuuluvainen, Ilkka Vanha-Majamaa, Pasi Puttonen. (2008). Microsites before and after restoration in managed Picea abies stands in southern Finland: effects of fire and partial cutting with dead wood creation. Silva Fennica vol. 42 no. 2 article id 250. https://doi.org/10.14214/sf.250
Keywords: biodiversity; boreal forest; regeneration; coarse woody debris; disturbance dynamics; CWD; managed forest
Abstract | View details | Full text in PDF | Author Info
Different types of microsites, e.g. CWD (coarse woody debris), mounds, and uprooting pits, are important for tree regeneration and biodiversity. However, microsite diversity is greatly reduced in managed stands. We studied how restoration treatments changed microsite distribution in mature managed Picea abies stands. Four cutting treatments were used: uncut, low-CWD (5 m3 ha–1 of down retention trees, DRT, and 50 m3 ha–1 of standing retention trees), intermediate-CWD (as previous but leaving 30 m3 ha–1 of DRT), and high-CWD (as previous but with 60 m3 ha–1 of DRT). Timber harvested from stands ranged from 108–168 m3 ha–1. Half of the stands were burned, and half remained unburned. Sampling was stratified into upland and paludified biotopes within each stand. The pre-treatment microsite distributions were dominated by level ground in both biotopes; mounds and microsites on or next to CWD or a stump were slightly more abundant in the paludified than in the upland biotopes. Microsites were more diverse after cutting, with and without fire. The cutting treatment increased the relative abundances of microsites on or next to CWD. Fire consumed small diameter dead wood and flattened mounds. Microsites were more diverse in paludified than in upland biotopes. The results demonstrate that microsite diversity can rapidly be restored to structurally impoverished managed Picea stands despite a large portion of wood volume being harvested.
  • Lilja-Rothsten, University of Helsinki, Dept. of Forest Ecology, Finland E-mail: saara.lilja@helsinki.fi (email)
  • Chantal, University of Helsinki, Dept. of Forest Ecology, Finland E-mail: mdc@nn.fi
  • Peterson, Dept. of Plant Biology, University of Georgia, Athens, GA, USA E-mail: cp@nn.us
  • Kuuluvainen, University of Helsinki, Dept. of Forest Ecology, Finland E-mail: tk@nn.fi
  • Vanha-Majamaa, The Finnish Forest Research Institute, Vantaa Unit, Finland E-mail: ivm@nn.fi
  • Puttonen, The Finnish Forest Research Institute, Vantaa Unit, Finland E-mail: pp@nn.fi
article id 267, category Research article
Manfred Gronalt, Peter Rauch. (2008). Vendor managed inventory in wood processing industries – a case study. Silva Fennica vol. 42 no. 1 article id 267. https://doi.org/10.14214/sf.267
Keywords: building materials; service level; solid structure timber; SST; wood construction
Abstract | View details | Full text in PDF | Author Info
Solid structure timber (SST) is an important building material in the wood construction business, in which its production volume is largely related to that respective business. Due to the large variability in the demand and seasonal factors, SST producers’ inventories are likely to be simultaneously overstocked for one type of timber and out of stock of another. An inventory policy that ensures a high service level and relatively low stocks is required. In the present paper, we propose the vendor managed inventory (VMI) approach for controlling the stock of deals that are produced at a sawmill and delivered as raw material for SST-production. We evaluate two VMI implementations against the actual inventory management for three different market scenarios. Furthermore, we layout the necessities for reconfiguring the business processes, and subsequently set up an organisational framework within VMI, which is indeed applicable in this segment of the woodworking industry. In our application background, VMI as an inventory control system is able to reduce the overall raw material stock by more than 37% by simultaneously increasing the SST service level.
  • Gronalt, BOKU – University of Natural Resources and Applied Life Sciences, Feistmantelstr. 4, 1180 Vienna, Austria E-mail: mg@nn.at (email)
  • Rauch, BOKU – University of Natural Resources and Applied Life Sciences, Feistmantelstr. 4, 1180 Vienna, Austria E-mail: peter.rauch@boku.ac.at
article id 266, category Research article
Mikko Havimo, Juha Rikala, Jari Sirviö, Marketta Sipi. (2008). Distributions of tracheid cross-sectional dimensions in different parts of Norway spruce stems. Silva Fennica vol. 42 no. 1 article id 266. https://doi.org/10.14214/sf.266
Keywords: Norway spruce; cell wall thickness; earlywood; latewood; tracheid dimension; tangential width; radial width
Abstract | View details | Full text in PDF | Author Info
Distributions of three cross-sectional dimensions: radial and tangential tracheid width, and cell wall thickness in different timber assortments of Norway spruce were investigated. Wood samples from a mature stand were measured with SilviScan. In the analysis, virtual trees were constructed from measurement data, and divided into three assortments: whole stem, top pulpwood and sawmill chips. Average values and distributions of the properties were calculated for all assortments, and distributions divided into earlywood and latewood across the whole tree assortment. There was considerable variation within latewood in all three cross-sectional dimensions, but variation in earlywood was slight in radial width and cell wall thickness. In earlywood, tangential tracheid width showed considerable internal variation, and the difference between earlywood and latewood in tangential width was small. Within-assortment variation of all three properties was larger than between assortments. We may conclude that only a moderate difference in pulp properties can be achieved by sorting raw material into sawmill chips and top pulpwood. Pulp fractionation into earlywood and latewood seems to be a more efficient method, since it gives classes with small within-class variation and distinct average properties. However, it should be kept in mind that the results are valid only in mature stands, where growth rate variation and juvenile wood content are small.
  • Havimo, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: mikko.havimo@helsinki.fi (email)
  • Rikala, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: jr@nn.fi
  • Sirviö, KCL, P.O. Box 70, FI-02151 Espoo, Finland E-mail: js@nn.fi
  • Sipi, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ms@nn.fi
article id 278, category Research article
Katri Luostarinen. (2007). The effect of annual ring orientation and drying method on deformations, casehardening and colour of silver birch (Betula pendula) boards. Silva Fennica vol. 41 no. 4 article id 278. https://doi.org/10.14214/sf.278
Keywords: wood; timber quality; dimensional stability; distortion; drying schedules; kiln drying; L*a*b* coordinates
Abstract | View details | Full text in PDF | Author Info
Deformations of timber, caused mainly by anisotropic shrinkage, can be partially directed by controlling annual ring orientation through different sawing patterns. Ring orientation also affects the movement of water from within the board to its surface, with rapidity of drying having implications for the wood colour. Here sawn silver birch (Betula pendula Roth) timber was classed into two groups according to ring orientation. Two drying methods were used. The final moisture content was lower and the colour lighter in dried boards with radial than with tangential flats, but deformations were larger in radial than in tangential boards. Both drying and ring orientation affected the final moisture content and moisture gradient of the boards. Very small differences in board sizes or shape had an effect on both colour and deformations. The results support the need for accurate sawing and for classing silver birch timber sawn into parquet billets according to ring orientation in order to optimise the drying quality.
  • Luostarinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: katri.luostarinen@joensuu.fi (email)
article id 273, category Research article
Stefan Mattson, Urban Bergsten, Tommy Mörling. (2007). Pinus contorta growth in boreal Sweden as affected by combined lupin treatment and soil scarification. Silva Fennica vol. 41 no. 4 article id 273. https://doi.org/10.14214/sf.273
Keywords: biomass; wood density; cultivation; lodgepole pine; lupinus; nitrogen inputs
Abstract | View details | Full text in PDF | Author Info
Effects of combining lupin (Lupinus nootkatensis L.) establishment and soil scarification on stem volume and stem biomass yield of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) were studied on a poor boreal site in Sweden 18 years after plantation. A field randomized block experiment was established with three different scarification techniques (disc trenching, moulding and ploughing) followed by establishment of lupins by either seeds or roots. There were three blocks without and two blocks with lupins. Overall, on average for the three soil scarification techniques, the lupin treatment significantly increased the volume per hectare by 102%.The lupin treatment significantly increased the stem volume per hectare by 236% for mounding and 139% for disc trenching, whereas the 55% increase for ploughing was not significant. The increase in the total stem biomass yield per tree was more pronounced for larger trees; 46% for average trees and 106% for dominant trees. However, there were no significant differences between scarification techniques for the lupin treatment in total stem biomass yield. Over the 18-year period, the increased growth rate following the lupin treatment resulted in a significantly decreased average stem basic wood density (on average 6%) for the sample trees. Because lupin is a nitrogen-fixing plant species, the large increase in tree growth following the lupin treatment was probably an effect of increased amount of nitrogen in the soil. The results indicate that use of lupin is a possible alternative to increase site productivity of lodgepole pine on poor boreal sites.
  • Mattson, Swedish University of Agricultural Sciences, Dept of Forest Ecology and Management, SE-901 83 Umeå, Sweden E-mail: sm@nn.se
  • Bergsten, Swedish University of Agricultural Sciences, Dept of Forest Ecology and Management, SE-901 83 Umeå, Sweden E-mail: ub@nn.se
  • Mörling, Swedish University of Agricultural Sciences, Dept of Forest Ecology and Management, SE-901 83 Umeå, Sweden E-mail: tommy.morling@ssko.slu.se (email)
article id 286, category Research article
Riitta Hänninen, A. Maarit I. Kallio. (2007). Economic impacts on the forest sector of increasing forest biodiversity conservation in Finland. Silva Fennica vol. 41 no. 3 article id 286. https://doi.org/10.14214/sf.286
Keywords: forest biodiversity conservation; roundwood market; forest industry production
Abstract | View details | Full text in PDF | Author Info
In the next coming years, political decisions will be made upon future actions to safeguard forest biodiversity in Southern Finland. We address the economic consequences on the Finnish forest sector of conserving additional 0.5% to 5% of the old growth forest land in Southern Finland. The impacts on supply, demand and prices of wood and forest industry production are analysed employing a partial equilibrium model of the Finnish forest sector. An increase in conservation raises wood prices and thus the production costs of the forest industry. This makes sawnwood production fall, but does not affect paper and paperboard production. The forest owners’ aggregated wood sales income is unaffected or slightly increased, because an increase in stumpage prices offsets the decrease in the harvests. If conservation increases wood imports, negative effects on forest industry become smaller whereas aggregated forest owners’ income may decline depending on the magnitude of import substitution.
  • Hänninen, Finnish Forest Research Institute, Unioninkatu 40 A, FI-00170 Helsinki, Finland E-mail: riitta.hanninen@metla.fi (email)
  • Kallio, Finnish Forest Research Institute, Unioninkatu 40 A, FI-00170 Helsinki, Finland E-mail: maarit.kallio@metla.fi
article id 285, category Research article
Heli Peltola, Antti Kilpeläinen, Kari Sauvala, Tommi Räisänen, Veli-Pekka Ikonen. (2007). Effects of early thinning regime and tree status on the radial growth and wood density of Scots pine. Silva Fennica vol. 41 no. 3 article id 285. https://doi.org/10.14214/sf.285
Keywords: thinning response; ring width; early wood; late wood; intra-ring wood density; X-ray densitometry
Abstract | View details | Full text in PDF | Author Info
  • Peltola, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: heli.peltola@joensuu.fi (email)
  • Kilpeläinen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: ak@nn.fi
  • Sauvala, Finnish Forest Research Institute, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ks@nn.fi
  • Räisänen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: tr@nn.fi
  • Ikonen, University of Joensuu, Faculty of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: vpi@nn.fi
article id 322, category Research article
Jaakko Repola. (2006). Models for vertical wood density of Scots pine, Norway spruce and birch stems, and their application to determine average wood density. Silva Fennica vol. 40 no. 4 article id 322. https://doi.org/10.14214/sf.322
Keywords: Norway spruce; Scots pine; silver birch; wood density; downy birch; mixed models
Abstract | View details | Full text in PDF | Author Info
The purpose of this study was to investigate the vertical dependence of the basic density of Scots pine, Norway spruce, and birch stems, and how such dependence could be applied for determining the average stem wood density. The study material consisted of 38 Scots pine (Pinus sylvestris), 39 Norway spruce (Picea abies [L.] Karst.) and 15 birch (Betula pendula and Betula pubescens) stands located on mineral soil sites in southern Finland. The stem material mainly represented thinning removal from stands at different stages of development. The linear mixed model technique, with both fixed and random effects, was used to estimate the model. According to the fixed part of the model, wood density was dependent on the vertical location along the stem in all three tree species. Wood density in pine decreased from the butt to the top, and the gradient in wood density was steep at the butt but decreased in the upper part of the stem. The vertical dependence was similar in birch, but the density gradient was much smaller. For spruce the vertical dependence of the basic density was moderate. The model can be calibrated for a tree stem when one or more sample disks are measured at freely selected heights. Using treewise calibrated predictions of the vertical density dependence and measured stem diameters, almost unbiased estimates, and lower prediction errors than with traditional methods, were obtained for the average stem wood density. The advantages of the method were greater for pine with a strong vertical dependence in basic density, than for spruce and birch.
  • Repola, Finnish Forest Research Institute, Rovaniemi Research Unit, Eteläranta 55, FI-96300 Rovaniemi, Finland E-mail: jaakko.repola@metla.fi (email)
article id 358, category Research article
Turgay Akbulut, Nadir Ayrilmis. (2006). Effect of compression wood on surface roughness and surface absorption of medium density fiberboard. Silva Fennica vol. 40 no. 1 article id 358. https://doi.org/10.14214/sf.358
Keywords: compression wood; medium density fiberboard; surface properties; surface analysis
Abstract | View details | Full text in PDF | Author Info
Compression wood is undoubtedly one of the most important raw material variables in wood based panel manufacturing. This study evaluated effect of compression wood on surface roughness and surface absorption (flow distance) of medium density fiberboards (MDF) manufactured from furnishes of pine (Pinus nigra Arnold var. pallasiana) containing compression wood. Panels were manufactured from two different portions of the furnish, one of the portions having a compression wood/normal wood ratio of 75/25, and the other having a ratio of 10/90. Surface absorption and surface roughness were determined according to (EN 382-1) and (ISO 4287), respectively. It was found that panels made from furnish with a 75/25 ratio had a significantly lower surface absorption value (255.78 mm) than panels made from furnish with a 10/90 ratio (317.95 mm). Surface roughness measurements based on three roughness parameters, average roughness (Ra), mean peak-to-valley height (Rz), and maximum peak-to-valley height (Ry) were considered to evaluate the surface characteristics of the panels and supported the above findings as the panels made from furnish with a 75/25 ratio had slightly rougher surface with average values of 4.15 µm (Ra). From the tests performed, we conclude that increasing of the compression wood portion increased the surface roughness and decreased the surface absorption value.
  • Akbulut, Istanbul University, Faculty of Forestry, Bahcekoy, TR-34473 Istanbul, Turkey E-mail: ta@nn.tr
  • Ayrilmis, Istanbul University, Faculty of Forestry, Bahcekoy, TR-34473 Istanbul, Turkey E-mail: nadiray@istanbul.edu.tr (email)
article id 354, category Research article
Mervi Talvitie, Olli Leino, Markus Holopainen. (2006). Inventory of sparse forest populations using adaptive cluster sampling. Silva Fennica vol. 40 no. 1 article id 354. https://doi.org/10.14214/sf.354
Keywords: coarse woody debris; adaptive cluster sampling; simple random sampling; drought damage; efficiency
Abstract | View details | Full text in PDF | Author Info
In many studies, adaptive cluster sampling (ACS) proved to be a powerful tool for assessing rare clustered populations that are difficult to estimate by means of conventional sampling methods. During 2002 and 2003, severe drought-caused damage was observed in the park forests of the City of Helsinki, Finland, especially in barren site pine and spruce stands. The aim of the present study was to examine sampling and measurement methods for assessing drought damage by analysing the effectiveness of ACS compared with simple random sampling (SRS). Horvitz-Thompson and Hansen-Hurwitz estimators of the ACS method were used for estimating the population mean and variance of the variable of interest. ACS was considerably more effective than SRS in assessing rare clustered populations such as those resulting from drought damage. The variances in the ACS methods were significantly smaller and the inventory efficiency in the field better than in SRS.
  • Talvitie, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: mervi.talvitie@helsinki.fi (email)
  • Leino, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ol@nn.fi
  • Holopainen, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ah@nn.fi
article id 479, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Ivar Gjerde, Vegard S. Gundersen. (2005). Historical logging, productivity, and structural characteristics of boreal coniferous forests in Norway. Silva Fennica vol. 39 no. 3 article id 479. https://doi.org/10.14214/sf.479
Keywords: boreal forest; stand structure; decaying wood; forest history; naturalness; selective logging; dead trees
Abstract | View details | Full text in PDF | Author Info
Conservation of forest biodiversity has brought about an interest in evaluating the naturalness of forests, and to locate and protect semi-natural and old-growth forests in the Fennoscandian countries. However, it is not always clear how natural these forests really are, and how the past management history has affected their present structural composition. We studied the relationships between cut stumps from historical logging activity (50–100 years ago) and forest structural characteristics of today in a total of 385 0.25 ha plots in three boreal coniferous forests which are parts of National Nature Reserves in Norway. We also studied how forest productivity influenced these relationships. In plots with negligible logging impact we found the amount of living trees, dead wood, and size of the oldest trees mainly to increase with increasing productivity, whereas the age of the oldest trees decreased. The amount of deciduous trees was generally low irrespective of productivity. The intensity of logging did not consistently influence most of these forest structural variables, neither at low- nor at high-productive sites. The only consistent relationship in all study areas was a decreasing amount of dead wood with increasing logging intensity at high-productive sites. Also, the decay class distribution of dead wood was more right-skewed (indicating on-going accumulation of dead wood) the more logging had occurred at high-productive sites. Except from the effects on dead wood, previous logging does not show up as a major determinant of other stand structures of today.
  • Storaunet, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway E-mail: ken.storaunet@skogforsk.no (email)
  • Rolstad, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway E-mail: jr@nn.no
  • Gjerde, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway E-mail: ig@nn.no
  • Gundersen, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway E-mail: vsg@nn.no
article id 375, category Research article
Edgar Víquez, Diego Pérez. (2005). Effect of pruning on tree growth, yield, and wood properties of Tectona grandis plantations in Costa Rica. Silva Fennica vol. 39 no. 3 article id 375. https://doi.org/10.14214/sf.375
Keywords: wood quality; teak; heartwood volume; stem form; knot-free volume
Abstract | View details | Full text in PDF | Author Info
Reduced plantation densities have the effect that obtaining natural pruning and stem straightness are less assured. The physiological process of self-pruning is replaced by manual pruning. Generally, plantations are denser and have more uniform spacing than natural forests. In many, if not most species, natural pruning is never a satisfactory option, even after branch senescence, if production of clear wood is a management objective. Natural pruning can only be considered on a species by species basis. This study reports on the first results of a pruning trial for Tectona grandis L.F. plantations in Costa Rica. The treatments consisted of pruning heights of 3.0, 4.0, and 5.0 meters, and the Control without pruning. Differences among treatments in DBH and total height were significant at 3.2, 5.2, and 6.1 years of age, but not at 7.3 years. Under an intensive pruning regime, a teak tree at rotation (20 years) may yield over 40% of knot-free volume (over 60% of the merchantable tree volume). Current findings open a scope for new management options, aiming at improving stem form and wood quality by means of an intensive pruning regime, without having a detrimental effect on tree growth and stand yield.
  • Víquez, Tropical Agricultural Research and Higher Education Center (CATIE), Apartado 7170 CATIE, Turrialba, Costa Rica E-mail: eviquez@catie.ac.cr (email)
  • Pérez, Ambiente Tierra S.A., Apartado 733-2250, Tres Ríos, Cartago, Costa Rica E-mail: dp@nn.cr
article id 389, category Research article
Ritva Toivonen, Eric Hansen, Erno Järvinen, Raija-Riitta Enroth. (2005). The competitive position of the Nordic wood industry in Germany – intangible quality dimensions. Silva Fennica vol. 39 no. 2 article id 389. https://doi.org/10.14214/sf.389
Keywords: wood products; quality; the intangible product component; performance
Abstract | View details | Full text in PDF | Author Info
This study examines the importance of various intangible product quality dimensions as perceived by wood-trading retailer and wholesaler companies in Germany. Using perceived importance and perceived performance, the study first examines the dimensionality of intangible product quality and then compares Nordic wood product suppliers with suppliers from other major supply regions. Data was collected from 76 German companies during 2000–2001. Results indicate that intangible product quality can be described in three dimensions, “Behaviour and Image”, “Serviceability and Environment”, and “Reliability”. Results also show that Nordic suppliers do not have a strong competitive position in Germany in terms of intangible product quality dimensions. Thus, Nordic suppliers could improve their competitive position by enhancing their service, logistics and other dimensions of the intangible product offering.
  • Toivonen, Pellervo Economic Research Institute PTT, Eerikinkatu 28 A, FI-00180, Helsinki, Finland E-mail: ritva.toivonen@dnainternet.net (email)
  • Hansen, Oregon State University, Dept. of Wood Science & Engineering, Richardson Hall 108, 97331-5751 Corvallis, OR, USA E-mail: eh@nn.us
  • Järvinen, Pellervo Economic Research Institute PTT, Eerikinkatu 28 A, FI-00180, Helsinki, Finland E-mail: ej@nn.fi
  • Enroth, Finnish Forest Research Institute, Unioninkatu 40 A, FI-00170 Helsinki, Finland E-mail: rre@nn.fi
article id 388, category Research article
Jacob Edlund, Mats Warensjö. (2005). Repeatability in automatic sorting of curved Norway spruce saw logs. Silva Fennica vol. 39 no. 2 article id 388. https://doi.org/10.14214/sf.388
Keywords: Picea abies; compression wood; stem form; bow; scanner; sorting
Abstract | View details | Full text in PDF | Author Info
Sawn wood from curved logs is prone to have cross grain and contain compression wood, both of which affect the dimensional stability. Different types of curvature can, however, have different effects on both the sawing process and board quality, which is why a standard measure of bow height alone is not enough to sort logs or set the log quality. The aim of this study was to evaluate the repeatability when sorting curved saw logs using a 3D log scanner. In the study, 56 logs were categorized into five different curvature types and four different degrees of curvature severity. The logs were run through a Rema 3D log scanner four times, and the external geometry was recorded. From the geometry data, variables describing log shapes were calculated and used to develop models using linear discriminant analysis, which was used to classify the logs according to curvature type. The accuracy and repeatability were evaluated for the classifications with Cohen’s simple Kappa coefficient. The results of this study showed that it is possible to sort logs by curve type using a 3D log scanner, although sorting by curve type was largely dependent on curve severity. The repeatability test determined that the chance of a curved log being graded identically two consecutive times was 0.40, measured as kappa.
  • Edlund, SLU, Department of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: jacob.edlund@spm.slu.se (email)
  • Warensjö, SLU, Department of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: mw@nn.se
article id 385, category Research article
Diego Pérez, Markku Kanninen. (2005). Effect of thinning on stem form and wood characteristics of teak (Tectona grandis) in a humid tropical site in Costa Rica. Silva Fennica vol. 39 no. 2 article id 385. https://doi.org/10.14214/sf.385
Keywords: sapwood; stem taper; basic density; heartwood; form factor
Abstract | View details | Full text in PDF | Author Info
The aim of the study was to evaluate the effects of thinning intensity on wood properties, such as heartwood proportion, wood basic density, and stem form of teak (Tectona grandis L.f.). The thinning trial was established on a teak plantation in a humid tropical site in northern Costa Rica. The moderate and heavy thinnings yielded the highest percentage of heartwood volume (25 to 30% of total stem volume). The differences between stem form factors under different treatments were not statistically significant after separating thinning effects from timing effects. Both the highest (> 0.65 g cm–3) and the lowest (< 0.50 g cm–3) wood density values were observed under light thinnings, making it difficult to establish a relationship. Large variations in wood properties found under different thinning regimes suggest that at early stages teak stands can be managed under different thinning programs without negatively affecting the quality of wood under humid tropical conditions.
  • Pérez, Ambiente Tierra S.A., Apartado 733-2250, Tres Ríos, Cartago, Costa Rica E-mail: diegoperez@costarricense.cr (email)
  • Kanninen, Center for International Forestry Research (CIFOR), Bogor, Indonesia E-mail: mk@nn.id
article id 400, category Research article
Antti Mutanen, Anne Toppinen. (2005). Finnish sawlog market under forest taxation reform. Silva Fennica vol. 39 no. 1 article id 400. https://doi.org/10.14214/sf.400
Keywords: forest taxation; reforms; roundwood supply; simultaneous equations
Abstract | View details | Full text in PDF | Author Info
The stepwise transition in forest taxation from site productivity tax to taxation of profits from timber sales was one of the major institutional changes to impact Finnish non-industrial private forest owners in the 1990s. In this study the effect of the forest taxation reform on the aggregate supply of sawlogs was investigated using time series analysis and quarterly data. In particular, we estimated two simultaneous equations systems for the pine and the spruce sawlog markets. According to the results, the forest taxation reform strengthened the supply of spruce and pine sawlogs in the anticipatory stage of the taxation reform in 1992. Also during the fiscal transition period, which started in 1993, the supply effect of the taxation reform has clearly been positive. The strong own-price elasticity of sawlog supply found in this study indicates high sensitivity to actual and expected wood price changes in the determination of sawlog supply in Finland. Furthermore, the results indicate that the theoretical assumption of a competitive market is suitable for the Finnish sawlog market, but that separate analysis of pine and spruce sawlogs provides additional insights into market behaviour.
  • Mutanen, Finnish Forest Research Institute, Joensuu Research Centre, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: antti.mutanen@metla.fi (email)
  • Toppinen, Finnish Forest Research Institute, Joensuu Research Centre, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: at@nn.fi
article id 399, category Research article
Torjus F. Bolkesjø. (2005). Projecting pulpwood prices under different assumptions on future capacities in the pulp and paper industry. Silva Fennica vol. 39 no. 1 article id 399. https://doi.org/10.14214/sf.399
Keywords: paper industry; Norway; capacity; partial equilibrium model; pulpwood; prices
Abstract | View details | Full text in PDF | Author Info
Capacity changes in the pulp and paper industry affect demand for pulpwood and thus pulpwood prices. This paper analyzes the impacts on roundwood prices in Norway of two possible capacity changes (one new machine and one close-down) that currently are high on the agenda in the Norwegian paper industry, and assesses the generality of the results obtained from these case studies. The two cases are implemented exogenously into a regionalized partial equilibrium forest sector model, and the capacity change scenarios are compared with a business as usual scenario assuming no demand shocks. The projected pulpwood prices change significantly in regions near mills where capacity shifts, at least for the close-down case, but only moderately at an aggregated national level. The reduction in prices under the close-down studied is higher than the price increase from the possible capacity increase case. The asymmetric price responses projected for the two case studies are supported by sensitivity analyses on other regions and cases (technologies). For the capacity increase case it is shown that the level of the projected pulpwood price is sensitive to assumptions on base-year prices and transport costs of imported roundwood, but the magnitudes of the price increases projected as a result of increased demand are less affected by these assumptions.
  • Bolkesjø, Norwegian University of Life Sciences, Dept. of Ecology and Natural Resource Management, Høyskoleveien 14, NO-1432 Ås, Norway E-mail: torjus.bolkesjo@umb.no (email)
article id 393, category Research article
Seppo Rouvinen, Anne Rautiainen, Jari Kouki. (2005). A relation between historical forest use and current dead woody material in a boreal protected old-growth forest in Finland. Silva Fennica vol. 39 no. 1 article id 393. https://doi.org/10.14214/sf.393
Keywords: Populus tremula; Pinus sylvestris; Picea abies; coarse woody debris; forest utilization; historical ecology; land-use history; nature conservation; spatial pattern analysis
Abstract | View details | Full text in PDF | Author Info
Assessing the human impact on the naturalness and vegetation characteristics of protected areas is one of the key issues when designing forest conservation networks in Fennoscandia. We studied the small-scale, detailed relationship between forest utilization history and the current availability of dead woody material in a protected old-growth forest area in North Karelia, eastern Finland. From the study area of 32.4 ha, all the stumps (diameter ≥ 5 cm and height < 1.3 m, classified as natural, man-made and of undetermined origin) were measured using 25 x 25 m sub-plots. Standing and fallen dead trees (dbh ≥ 5 cm) were measured on 50 x 50 m plots in an area of 7.8 ha. The average number of stumps was 130 per ha, and over half of the stumps were classified as man-made. However, the historical documents since the 1910s showed no logging in the area: some of the largest man-made stumps probably originated from an earlier time, but most of those stumps were made considerably later. The variation in the total number of stumps (per ha) was great (range 0–560/ha, 0–16 m2/ha), with no clear clustering in space. However, clustering of man-made stumps was detected. The average volume of pooled standing and fallen trees was 84 m3/ha, with a range of 37–146 m3/ha. The other noticeable man-made disturbance besides logging was notching of aspens, which has a scatteredly significant influence on the amount of dead trees. In conclusion, the protected old-growth forest was not as a whole in a natural state but showed different degrees of human impact from virtually untouched patches to quite heavily managed patches. The results suggest that the number of man-made stumps may be a relatively quick and easy method of assessing the naturalness of woody biomass structure in the Fennoscandian boreal forests.
  • Rouvinen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: seppo.rouvinen@joensuu.fi (email)
  • Rautiainen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: ar@nn.fi
  • Kouki, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jk@nn.fi
article id 415, category Research article
Sandhya Samarasinghe, Don Kulasiri. (2004). Stress intensity factor of wood from crack-tip displacement fields obtained from digital image processing. Silva Fennica vol. 38 no. 3 article id 415. https://doi.org/10.14214/sf.415
Keywords: Pinus radiata; wood; fracture toughness; stress intensity factor; digital image correlation; orthotropic fracture theory
Abstract | View details | Full text in PDF | Author Info
Stress intensity factor of radiata pine (Pinus radiata) in Tangential-Longitudinal opening mode was determined from crack-tip displacement fields obtained from digital image correlation in conjunction with orthotropic fracture theory. For lower loads, experiments agreed with the linear elastic fracture theory but for higher loads, stress intensity factor and load relationship was nonlinear. For 41% of the specimens tested, tip-displacement based stress intensity factor agreed with that based on the ASTM standard formula for lower loads but deviated for higher loads closer to failure. The tip displacement plots showed that the nonlinear behaviour is due to large displacements which we attributed to large plastic deformations and/or micro-cracking in this region. The other 59% specimens showed a similar trend except that the crack-tip based stress intensity factor was consistently higher than the value obtained from the standard formula. The fracture toughness from tip displacements was larger than the standard values for all specimens and the two were related by a logarithmic function with an R2 of 0.61. The study also established that fracture toughness increases with the angle of inclination of the original crack plane to the Radial Longitudinal plane.
  • Samarasinghe, Lincoln University, P.O. Box 84, Canterbury, New Zealand E-mail: ss@nn.nz
  • Kulasiri, Lincoln University, P.O. Box 84, Canterbury, New Zealand E-mail: kulasird@lincoln.ac.nz (email)
article id 426, category Research article
Uwe Schmitt, Risto Jalkanen, Dieter Eckstein. (2004). Cambium dynamics of Pinus sylvestris and Betula spp. in the northern boreal forest in Finland. Silva Fennica vol. 38 no. 2 article id 426. https://doi.org/10.14214/sf.426
Keywords: birch; boreal forest; Scots pine; cambium dynamics; wood formation; pinning technique; light microscopy
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Wood formation dynamics of pine and birch along a south-north transect in Finnish Lapland were determined by the pinning technique. For all trees at all sites a more or less sigmoid shape of the wood formation intensity is characteristic with a slow beginning, a faster growth in the middle and a decreasing activity towards the end of the vegetation period. Wood formation of pine started at sites 1–3 (southern sites) in the second week of June and at sites 4 and 5 (northern sites) only in the last week of June, whereas wood formation ended within the first half of August. Wood formation of birch started in the second half of June and ended around the beginning of August. First cells were laid down by pine and birch when the temperature sum had reached the level of 85 to 90 degree days and 110 to 120 degree days, respectively. The intensity of wood formation in pine was highest in July, in birch within two weeks in the middle of July. Wood formation in pine lasted for about seven weeks at the southernmost and about six weeks at the northernmost site. In birch, the duration of wood formation was about five weeks at the southernmost site and around three weeks at the other sites.
  • Schmitt, Federal Research Centre for Forestry and Forest Products, Institute for Wood Biology and Wood Protection, and University of Hamburg, Chair for Wood Biology, Leuschnerstr. 91, P. O. Box 800209, D-21002 Hamburg, Germany E-mail: u.schmitt@holz.uni-hamburg.de (email)
  • Jalkanen, Finnish Forest Research Institute, Rovaniemi Research Station, Box 16, FI-96301 Rovaniemi, Finland E-mail: rj@nn.fi
  • Eckstein, Federal Research Centre for Forestry and Forest Products, Institute for Wood Biology and Wood Protection, and University of Hamburg, Chair for Wood Biology, Leuschnerstr. 91, P. O. Box 800209, D-21002 Hamburg, Germany E-mail: de@nn.de
article id 424, category Research article
Mats Warensjö, Göran Rune. (2004). Stem straightness and compression wood in a 22-year-old stand of container-grown Scots pine trees. Silva Fennica vol. 38 no. 2 article id 424. https://doi.org/10.14214/sf.424
Keywords: Pinus sylvestris; stem form; eccentricity; reaction wood
Abstract | View details | Full text in PDF | Author Info
The distribution of compression wood in relation to eccentric growth and development of stem straightness was studied in a 22-year-old Scots pine (Pinus sylvestris L.) stand in central Sweden that was established with container-grown seedlings. Stem straightness was measured on the same 440 trees in 1986 and 1997. The number of stems with straight base sections increased from 60% in 1986 to 89% in 1997. Measurements of 72 sample trees in 2001 showed that 96% of the trees had developed straight stem bases. External geometry data of the logs was obtained with a Rema 3D log scanner. A sub-sample of 16 trees was randomly selected for analysis of compression wood distribution and eccentricity measurements. From each tree, 11 discs were cut at every 60 cm along the stem. All discs, except one, contained compression wood. Compression wood and pith eccentricity was most pronounced near the stem base but not significantly correlated to basal sweep. Severe compression wood content was correlated to pith eccentricity and bow height. In general, correlations were better for the basal sections of the logs. Even though most trees were straight, they contained large amounts of compression wood. It is evident that eccentric growth and compression wood formation play major roles in the development of stem straightness. In several stems, a spiral compression wood distribution pattern was found. Reasons for this are discussed.
  • Warensjö, Department of Forest Products and Markets, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: mats.warensjo@spm.slu.se (email)
  • Rune, Department of Forestry and Wood Technology, Dalarna University, SE-776 98 Garpenberg, Sweden E-mail: gr@nn.se
article id 439, category Research article
Christina Lundgren. (2004). Microfibril angle and density patterns of fertilized and irrigated Norway spruce. Silva Fennica vol. 38 no. 1 article id 439. https://doi.org/10.14214/sf.439
Keywords: ring width; growth rate; juvenile wood; MoE; X-ray diffraction
Abstract | View details | Full text in PDF | Author Info
Two Norway spruce nutrient optimisation trials, one in the north of Sweden and one in the south, were used to study the effects of intensive growth and fertilization on wood density and microfibril angle. Three different treatments and a control were available; daily irrigation, daily liquid fertilization and solid fertilization. The nutrient optimisation was based on foliage analysis and the solid fertilization essentially comprised the same amount of nutrients but was applied annually in solid form. Measurements of density and microfibril angle (MFA) were performed using X-ray diffraction. Growth rate, expressed as a transformation of annual ring width, was very important at the southern site when the effect of cambial maturation had been taken into account. Effects of both fertilization and irrigation remained strong and significant for density, and irrigation was a significant factor explaining MFA. At the northern site distance from pith was the dominant factor but the effect of growth rate was also strong and the treatment effect was significant for both density and MFA. The combination of higher MFA and decrease in density for fertilized trees resulted in a lower calculated strength of the wood. An over 100% increase in ring width only corresponded to approximately a 20% decrease in wood density and the production of wood dry matter was hence increased by treatments.
  • Lundgren, SLU, Dept. of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: christina.lundgren@spm.slu.se (email)
article id 438, category Research article
Christina Lundgren. (2004). Cell wall thickness and tangential and radial cell diameter of fertilized and irrigated Norway spruce. Silva Fennica vol. 38 no. 1 article id 438. https://doi.org/10.14214/sf.438
Keywords: cell wall thickness; tangential tracheid diameter; radial tracheid diameter; tracheid dimensions; nutrient optimisation; juvenile wood
Abstract | View details | Full text in PDF | Author Info
Two Norway spruce nutrient trials were used to evaluate the effects of fertilization and irrigation on transverse tracheid dimensions. Three different treatments and a control (C) were used; daily irrigation (I), daily liquid fertilization (IL) and an annual solid fertilization (F). The nutrient optimisation was based on foliage analysis and both liquid and solid fertilization essentially comprised the same amount of nutrients but the latter was applied annually in solid form. The cell measurements; cell wall thickness, radial and tangential cell widths, were obtained using image analysis (SilviScan at CSIRO, Melbourne, Australia). Mean annual cell wall thickness was decreased by fertilization (F and IL) on both sites whereas no effect of the irrigation on wall thickness could be detected. Radial cell width was increased by treatment at Flakaliden but at Asa the effect of irrigation and fertilization was reversed when the data structure i.e. development from pith and out and annual ring width was taken into account. Tangential cell width was not significantly affected by treatment at Flakaliden. At Asa fertilization caused a small increase on tangential cell width. Ring width was positively affected by treatment and is an important factor explaining the effects on primarily cell wall thickness and radial cell width.
  • Lundgren, SLU, Dept. of Forest Products and Markets, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: christina.lundgren@spm.slu.se (email)
article id 434, category Research article
Igor Drobyshev, Mats Niklasson, Per Angelstam. (2004). Contrasting tree-ring data with fire record in a pine-dominated landscape in the Komi Republic (Eastern European Russia): recovering a common climate signal. Silva Fennica vol. 38 no. 1 article id 434. https://doi.org/10.14214/sf.434
Keywords: boreal; climate; earlywood; latewood; chronology; seasonal dating; weather control; natural disturbance
Abstract | View details | Full text in PDF | Author Info
For the period 1420–1960 we contrasted fire events reconstructed at 14 sites distributed over a 50 km x 50 km area in the central part of the Komi Republic (European Russia) with a set of tree-ring width chronologies of Scots pine (Pinus sylvestris L.), developed for the same area. Our aim was to infer common climatic information contained in tree-ring variables and independently dated fire events with the help of a superposed epoch analysis. The strongest weather–growth link was shown for the latewood width, which was positively correlated with the temperature in April–May and July–August of the current growth season and with previous year precipitation in July–August. Earlywood width was positively affected by previous year precipitation in May and November. The relationship between yearly ring variables and multiple-site fire events was dependent on the seasonal timing of fire events as recorded in the scars. In years with early-season fires (which made up 37% of all fires dated with seasonal resolution) total ring width was significantly narrower. In years with late-season fires (63%) total ring width, earlywood, and latewood width were significantly wider. Years with late-season fires tended to be associated with local highs of the latewood width chronologies over 1400–1960, which implied a link between decadal-scale climate variation and fire regime of the area.
  • Drobyshev, SUFOR Project, Department of Plant Ecology and Systematics, Ecology Building, Sölvegatan 37, Lund University, SE-223 62 Lund, Sweden E-mail: igor.drobyshev@ekol.lu.se (email)
  • Niklasson, SUFOR Project, Southern Swedish Forest Research Centre, SLU, P.O. Box 49, SE-230 53 Alnarp, Sweden E-mail: mn@nn.se
  • Angelstam, Grimsö Wildlife Research Station, Department of Conservation Biology, Forest Faculty, SLU, SE-730 91 Riddarhyttan, Sweden E-mail: pa@nn.se
article id 487, category Research article
Åsa Gustafsson. (2003). Logistic services as a competitive means – segmenting the retail market for softwood lumber. Silva Fennica vol. 37 no. 4 article id 487. https://doi.org/10.14214/sf.487
Keywords: service requirements; retail segments; softwood lumber
Abstract | View details | Full text in PDF | Author Info
Softwood lumber has been considered traditionally as commodity. Subsequently brand names and trademarks were of subordinate value and competition was based on price. Recently, retailers have grown substantially and are forcing their suppliers to improve the production and delivery of products. As retailers are getting more diverse and powerful, suppliers are forced to adapt to the retailers’ service requirements. The new situation also brings opportunities for the sawmills to develop their competitive advantage. The retail industry is continuously changing, and in order for sawmills to develop and offer what retailers are asking for, it is necessary that they understand and interpret retailers’ requirements correctly. One way for sawmills to be successful is to develop accurate service elements and to use the service elements as a segmentation base in order to structure their customer base. This study shows that retailers place considerable emphasis on delivery and value-added logistical services. It generates three hypotheses concerning the following potential retail segments; turnover, category, and customer base.
  • Gustafsson, School of Industrial Engineering (IPS), Växjö University, SE-351 95 Växjö, Sweden E-mail: asa.gustafsson@ips.vxu.se (email)
article id 494, category Research article
Antero Varhimo, Soili Kojola, Timo Penttilä, Raija Laiho. (2003). Quality and yield of pulpwood in drained peatland forests: pulpwood properties of Scots pine in stands of first commercial thinnings. Silva Fennica vol. 37 no. 3 article id 494. https://doi.org/10.14214/sf.494
Keywords: Pinus sylvestris; peatland; thinning; silviculture; pulpwood; fiber; pulping
Abstract | View details | Full text in PDF | Author Info
The inherent structural dynamics of drained peatland forests may result in a great variation in various wood and fiber properties. We examined variation in fiber and pulp properties i) among stands, ii) among trees within stands, and iii) within trees in young stands dominated by Scots pine (Pinus sylvestris L.). The stands, selected to cover a maximal range of the potential variation, were all at a stage of development where the first commercial thinnings would be feasible. Differences in the processability of the thinning removals were small. In similar kraft cooking conditions, a 5-unit variation in the kappa number of unbleached pulp was observed among the stands. Stand origin had no effect on pulp bleaching. The wood formed prior to drainage had a higher density, shorter fibers, was slightly slower delignified by cooking, and its yield was slightly lower than that of post-drainage wood. These properties, except for high density, are typical for juvenile wood in general, and at stand level they did not correlate with the proportion of pre-drainage wood. When the variation in fiber and pulp properties was broken down into its components, most of it was derived from tree-level in all the cases. On average, the fiber and pulp properties did not differ from those observed for first-thinning pulpwood from upland sites. Consequently, peatland-grown pulpwood may be mixed with other pulpwood in industrial processes. It would probably be best suited as the raw material for pulps with high bonding requirements, e.g. in the top ply of multi-ply board grades or in some specialty grades.
  • Varhimo, KCL, P.O. Box 70, FIN-02151 Espoo, Finland E-mail: antero.varhimo@kcl.fi (email)
  • Kojola, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: sk@nn.fi
  • Penttilä, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: sp@nn.fi
  • Laiho, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: raija.laiho@helsinki.fi
article id 503, category Research article
Jyrki Hytönen. (2003). Effects of wood, peat and coal ash fertilization on Scots pine foliar nutrient concentrations and growth on afforested former agricultural peat soils. Silva Fennica vol. 37 no. 2 article id 503. https://doi.org/10.14214/sf.503
Keywords: wood ash; afforestation; Scots pine; vegetation control; herbicides; coal ash; peat ash; peat soils
Abstract | View details | Full text in PDF | Author Info
The effects of ash and commercial fertilizers on the foliar nutrient concentrations and stand growth of Scots pine were studied in four field experiments established on former cultivated peat soils. The aims were to compare ash types (wood, peat and coal ash), study the effects of ash treatment (pelletization), compare ash fertilization with commercial fertilizers, and to study the interaction between ash fertilization and weed control. Foliar samples were collected 1–3 years and 7–8 years after fertilization. In the unfertilized plots, the foliar nitrogen and phosphorus concentrations were fairly high, while those of potassium were low in all the experiments. The boron levels were low in three out of the four experiments. Application of either loose or pelletized wood ash, as well as of commercial fertilizers, increased foliar potassium and boron concentrations, and thus successfully remedied the existing nutrient imbalances and deficiencies. Since phosphorus deficiencies are rarely encountered on field afforestation sites, poor-quality wood ash with low phosphorus concentration could be used. Peat ash containing phosphorus, but only small amounts of potassium and boron, was not found to be very suitable for soil amelioration in connection with field afforestation. Coal ash, containing only small amounts of potassium, was a good source of boron for pine even when used in small amounts, and thus it can be used in cases where boron deficiencies alone are encountered. Wood ash significantly increased the height growth of Scots pines in two of the experiments, but peat ash and coal ash had no statistically significant effect. Wood ash increased the number of healthy seedlings. Vegetation control decreased seedling mortality by 24%, increased the growth of pine and decreased the proportion of trees damaged by elk and by deciduous trees.
  • Hytönen, Finnish Forest Research Institute, Kannus Research Station, P.O. Box 44, FIN-69101 Kannus, Finland E-mail: jyrki.hytonen@metla.fi (email)
article id 516, category Research article
Celeste Lacuna-Richman. (2003). Ethnicity and the utilization of non-wood forest products: findings from three Philippine villages. Silva Fennica vol. 37 no. 1 article id 516. https://doi.org/10.14214/sf.516
Keywords: non-wood forest products (NWFPs); indigenous people; migrants; subsistence; market; Philippines
Abstract | View details | Full text in PDF | Author Info
The utilization and trade of non-wood forest products in three villages in the Philippines were compared in this study. Two villages were situated close to each other on the Island of Palawan. The Tagbanua, an indigenous people, inhabited one village; migrants from the Visayas Region of the Philippines populated the other. The third village is located on the Island of Leyte, in the Visayas Region, populated by native Visayan settlers. There was no significant difference in the number of NWFPs utilized by the indigenous people and the migrants. However, there was a wide disparity in income between the two groups, with migrants earning more, partly due to the marketing of commercial NWFPs. This gap could be decreased by fairer trading practices that are dependent in part on better educational opportunities, land rights, legal assistance and access to markets for the Tagbanua. Specific socioeconomic characteristics, such as the presence of a hunter within the household and size of the family were found to have a positive correlation with the use of NWFPs in some study villages. Income and the food expenditure of the household were inversely related with the use of NWFPs in the native Visayan village.
  • Lacuna-Richman, Faculty of Forestry, University of Joensuu, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: celeste.lacuna-richman@forest.joensuu.fi (email)
article id 514, category Research article
Jukka Malinen. (2003). Locally adaptable non-parametric methods for estimating stand characteristics for wood procurement planning. Silva Fennica vol. 37 no. 1 article id 514. https://doi.org/10.14214/sf.514
Keywords: stand characteristics; local non-parametric estimation; MSN method; wood procurement planning
Abstract | View details | Full text in PDF | Author Info
The purpose of this study was to examine the use of the local adaptation of the non-parametric Most Similar Neighbour (MSN) method in estimating stand characteristics for wood procurement planning purposes. Local adaptation was performed in two different ways: 1) by selecting local data from a database with the MSN method and using that data as a database in the basic k-nearest neighbour (k-nn) MSN method, 2) by selecting a combination of neighbours from the neighbourhood where the average of the predictor variables was closest to the target stand predictor variables (Locally Adaptable Neighbourhood (LAN) MSN method). The study data used comprised 209 spruce dominated stands located in central Finland and was collected with harvesters. The accuracy of the methods was analysed by estimating the tree stock characteristics and the log length/diameter distribution produced by a bucking simulation. The local k-nn MSN method was not notably better than the k-nn MSN method, although it produced less biased estimates on the edges of the input space. The LAN MSN method was found to be a more accurate method than the k-nn methods.
  • Malinen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: jukka.malinen@joensuu.fi (email)
article id 525, category Research article
Thomas Knoke. (2002). Value of complete information on red heartwood formation in beech (Fagus sylvatica). Silva Fennica vol. 36 no. 4 article id 525. https://doi.org/10.14214/sf.525
Keywords: value of information; economics of beech; red heartwood; silvicultural treatment
Abstract | View details | Full text in PDF | Author Info
Beech (Fagus sylvatica L.) is the most important deciduous tree species in Germany. The wood of beech shows normally a bright colour (white beech) as long as no coloured heartwood has been formed. The facultative heartwood formation is induced when oxygen enters central parts of older trees, where dead or at least less vital parenchyma exist. The coloured heartwood is usually called ‘red heartwood’. Beech without red heartwood can preferably be found in younger trees which show a high water content even in central parts of the stem. The presence of red heartwood is regarded as a severe reduction of timber quality. Numerous studies have investigated opportunities to derive information on the presence and characteristics of red heartwood of standing beech trees. But until now it has not been tested whether such information could be helpful to improve the economics of beech-silviculture. This paper investigates whether complete information on the heartwood of standing beech could be useful to control the proportion of discoloured timber harvested during one rotation. It is also examined, which kind of information on the heartwood could be used to improve the economic results. To verify this, simulations based on simple algorithms were conducted. The general assumption was made that all information on the heartwood would be available. The results show that information which is restricted on the mere existence of red heartwood is neither suited to significantly reduce the amount of coloured timber nor is it possible to improve economic results based on this information. Only based on information on the recent formation of red heartwood of beech, which is actually still white the amount of discoloured timber can be reduced significantly. Consequently the discounted cash flows can only be substantially improved based on information on an expected formation of recent red heartwood.
  • Knoke, Institute of Silviculture and Forest Management, Technische Universität München, Am Hochanger 13, D-85354 Freising, Germany E-mail: knoke@wbfe.forst.tu-muenchen.de (email)
article id 542, category Research article
Håkan Lindström. (2002). Intra-tree models of juvenile wood in Norway spruce as an input to simulation software. Silva Fennica vol. 36 no. 2 article id 542. https://doi.org/10.14214/sf.542
Keywords: Picea abies; image analysis; juvenile wood; growth conditions
Abstract | View details | Full text in PDF | Author Info
Juvenile wood found in the first 5–25 growth rings of a conifer has a structure and properties that differ from mature wood. Juvenile wood is therefore said to influence processing and the end-use of sawn products. Consequently, models describing the juvenile wood content, within and between trees, could be useful in improving the utilisation and value of wood as an industrial raw material. The objective of the present study was to develop juvenile wood models, based on Norway spruce trees, which could be used within a model system for conversion simulation studies. Nineteen stands of Norway spruce (Picea abies [L.] Karst.) were selected throughout Sweden. Based on DBH, two small, two medium, and two large diameter timber trees were taken from each stand. DBH varied between 180–470 mm, tree height between 17–34 m, and total age between 51–152 years. Each selected tree was cross-cut into logs; discs were prepared from the large end of each log and from the top end of the top log. Image analysis was used to determine growth ring development on sampled discs. Using tree and growth variables, the juvenile core radius and the logarithmic value of juvenile wood percentage were modelled. The two models had an R2Adj of 0.71 and 0.88 respectively.
  • Lindström, University of Canterbury, School of Forestry, Private Bag 4800, Christchurch, New Zealand E-mail: lindstromhakan@netscape.net (email)
article id 563, category Research article
Timo Pakkala, Ilkka Hanski, Erkki Tomppo. (2002). Spatial ecology of the three-toed woodpecker in managed forest landscapes. Silva Fennica vol. 36 no. 1 article id 563. https://doi.org/10.14214/sf.563
Keywords: three-toed woodpecker; territory quality; landscape quality; critical threshold value; metapopulation theory; metapopulation capacity; Finnish National Forest Inventory
Abstract | View details | Full text in PDF | Author Info
The effects of landscape structure and forestry on the abundance and dynamics of boreal forest bird species have been studied widely, but there are relatively few studies in which the spatial structure and quality of the landscape have been related to the spatial ecology of bird species. In this paper, we present methods to measure territory and landscape quality for the three-toed woodpecker (Picoides tridactylus) and similar territorial forest bird species based on data from the Finnish multi-source national forest inventory and metapopulation theory. The three-toed woodpecker was studied with territory mapping within an area of 340 square km in southern Finland in 1987–2000. Altogether 195 breeding territory sites were observed. The spatial occurrence of the territories was aggregated, and the highest densities were observed in spruce-dominated old-growth forest areas. Both territory and landscape quality had significant consequences for the occurrence of the three-toed woodpecker. The spatial patterning and permanence of breeding and non-breeding territories were influenced by a combination of spatial dynamics of the species and the quality of the landscape, the latter being much influenced by forestry. The landscape-level spatial occurrence of the three-toed woodpecker in the study area may represent source-sink dynamics. The results of this paper suggest the presence of threshold values at different spatial scales, which may determine the occurrence of the three-toed woodpecker and similar species in managed forest landscapes.
  • Pakkala, Finnish Museum of Natural History, University of Helsinki, P.O. Box 17, FIN-00014 University of Helsinki, Finland E-mail: timo.pakkala@helsinki.fi (email)
  • Hanski, Department of Ecology and Systematics, University of Helsinki, P.O. Box 47, FIN-00014 University of Helsinki, Finland E-mail: ih@nn.fi
  • Tomppo, Finnish Forest Research Institute, Unioninkatu 40 A, FIN-00170 Helsinki, Finland E-mail: et@nn.fi
article id 555, category Research article
Leena Karjalainen, Timo Kuuluvainen. (2002). Amount and diversity of coarse woody debris within a boreal forest landscape dominated by Pinus sylvestris in Vienansalo wilderness, eastern Fennoscandia. Silva Fennica vol. 36 no. 1 article id 555. https://doi.org/10.14214/sf.555
Keywords: forest dynamics; disturbances; dead wood; Scots pine; tree death
Abstract | View details | Full text in PDF | Author Info
The amount, variability, quality and spatial pattern of coarse woody debris (CWD) on mineral soil sites was studied within a natural Pinus sylvestris L. dominated boreal forest landscape in Russian Viena Karelia. Data on the total CWD was collected on 27 sample plots (20 m x 100 m) and data on large CWD was surveyed along four transects (40 m wide and up to 1000 m long). The mean volume of CWD (standing and down combined) was 69.5 m3 ha–1, ranging from 22.2 m3 ha–1 to 158.7 m3 ha–1 from plot to plot. On average, 26.9 m3 ha–1 (39%) of CWD was standing dead wood and 42.7 m3 ha–1 (61%) down dead wood. The CWD displayed a wide range of variation in tree species, tree size, stage of decay, dead tree type and structural characteristics, creating a high diversity of CWD habitats for saproxylic organisms. Large CWD was almost continuously present throughout the landscape and its overall spatial distribution was close to random, although a weak autocorrelation pattern was found at distances less than about 50 m. On small spatial scales total CWD showed wide variation up to a sample area of about 0.1 ha, beyond which the variation stabilized. The fire history variables of the sample plots were not related to the amount of CWD. This and the spatial pattern of CWD suggest that the CWD dynamics in this landscape was not driven by fire, but by more or less random mortality of trees due to autogenic causes of death.
  • Karjalainen, Department of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: lk@nn.fi
  • Kuuluvainen, Department of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: timo.kuuluvainen@helsinki.fi (email)
article id 554, category Research article
Seppo Rouvinen, Timo Kuuluvainen, Juha Siitonen. (2002). Tree mortality in a Pinus sylvestris dominated boreal forest landscape in Vienansalo wilderness, eastern Fennoscandia. Silva Fennica vol. 36 no. 1 article id 554. https://doi.org/10.14214/sf.554
Keywords: dead wood; disturbance dynamics; spatial pattern analysis; mortality agent; forest structure; temporal variation
Abstract | View details | Full text in PDF | Author Info
Tree mortality and its causes and spatial pattern were examined along four transects (width 40 m, length 2550–3960 m), with a total length of 12 190 m and area of 48.8 ha, in a Pinus sylvestris L. dominated, boreal forest landscape. Tree mortality was determined within a time window of 3 years by identifying those trees (dbh ≥ 10 cm) along the transects that fitted into one of the three categories: 1) current mortality: trees that had died during the year of survey (1998), 2) recent mortality: trees that had died during the year (1997) before the survey year, and 3) predicted mortality: trees that were expected to die during the year (1999) following the survey year. Long-term tree mortality was studied on 10 plots (20 m x 100 m) by dating 87 dead trees using dendrochronological methods. The mean current mortality was 1.4 m3 ha–1 (3.7 trees ha–1). Both the recent and predicted mortalities were also 1.4 m3 ha–1. Mortality was, on the average, higher on peatlands than on mineral soils. The highest mortality was found within an area recently flooded by beavers. Over half of the examined trees (52%) were judged to die without any visible signs of an external abiotic cause. At the landscape scale, tree mortality was continuous although somewhat aggregated in space. Of the 66 dated standing dead Pinus trees, 23 (35%) had died during the 19th century and two during the 18th century, demonstrating that dead Pinus can remain standing for long periods of time before falling. Our results show that autogenic mortality of individual trees or small groups of trees was the predominant mode of disturbance in this Pinus dominated landscape.
  • Rouvinen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: seppo.rouvinen@forest.joensuu.fi (email)
  • Kuuluvainen, University of Helsinki, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: tk@nn.fi
  • Siitonen, Finnish Forest Research Institute, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: juha.siitonen@metla.fi
article id 582, category Research article
Kari Kangas, Pasi Markkanen. (2001). Factors affecting participation in wild berry picking by rural and urban dwellers. Silva Fennica vol. 35 no. 4 article id 582. https://doi.org/10.14214/sf.582
Keywords: non-wood forest products; wild berries; participation; household behaviour
Abstract | View details | Full text in PDF | Author Info
The purpose of this study was to examine the participation of urban and rural dwellers in the activity of berry-picking. The respondents in the study lived in the city of Joensuu and in the municipality of Ilomantsi, in eastern Finland. 68% of Joensuu households compared with 82% of those in Ilomantsi participated in berry-picking. These evident differences in the participation rates may be largely due to the higher costs incurred by urban dwellers in picking, since the probability of participation was not significantly higher for Ilomantsi households compared with those in Joensuu who had access to a summer-cottage which was likely to be located near the berry resources. In both municipalities, the participants were divided into two groups according to the nature of their participation in the activity. The larger group – termed ordinary pickers – were characteristically younger families with children, while the other group, termed active pickers, were distinctly more advanced in age. The quantities picked for home consumption by the groups of pickers in Ilomantsi were twice as large as those picked by the corresponding groups in Joensuu. In Joensuu, households were not significantly involved in commercial picking.
  • Kangas, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: kari.kangas@joensuu.fi (email)
  • Markkanen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: pm@nn.fi
article id 590, category Research article
Anna Saarsalmi, Eino Mälkönen, Sirpa Piirainen. (2001). Effects of wood ash fertilization on forest soil chemical properties. Silva Fennica vol. 35 no. 3 article id 590. https://doi.org/10.14214/sf.590
Keywords: Pinus sylvestris; wood ash; Picea abies; nutrients; acidity; neutralization; pH
Abstract | View details | Full text in PDF | Author Info
The effects of wood ash fertilization on soil chemical properties were studied in three young Scots pine (Pinus sylvestris L.) plantations and a Norway spruce (Picea abies (L.) Karst.) plantation with different site fertility in southern Finland. The dose of 3 t ha–1 of loose wood ash was applied to 4 replicate plots (25 x 25 m) at each experiment. Humus layer and mineral soil samples were taken before the treatment and 7 and 16 years after wood ash application. Results showed that neutralization as well as fertilization effects of wood ash on forest soil were of long duration. An ash-induced pH increase of 0.6–1.0 pH units and exchangeable acidity (EA) decrease of 58–83% were detected in the humus layer 16 years after wood ash application. The decrease in acidity was most pronounced on the Calluna site with initially the lowest pH and highest EA. In the mineral soil the increase in pH was observed later than in the humus layer. After 16 years, the mineral soil pH was increased (0.2–0.3 pH units) on the Vaccinium and Myrtillus sites. A corresponding and in most cases a significant increase in the extractable Ca and Mg concentrations was detected in both the humus layer and in the mineral soil. Wood ash significantly increased the effective cation exchange capacity (CECe) and base saturation (BS) but decreased the concentration of exchangeable Al in both soil layers on all the sites. No response of N availability to wood ash application could be found.
  • Saarsalmi, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: anna.saarsalmi@metla.fi (email)
  • Mälkönen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: em@nn.fi
  • Piirainen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: sp@nn.fi
article id 588, category Research article
Marjut Ihalainen, Timo Pukkala. (2001). Modelling cowberry (Vaccinium vitis-idaea) and bilberry (Vaccinium myrtillus) yields from mineral soils and peatlands on the basis of visual field estimates. Silva Fennica vol. 35 no. 3 article id 588. https://doi.org/10.14214/sf.588
Keywords: Vaccinium myrtillus; Vaccinium vitis-idaea; non-wood forest products
Abstract | View details | Full text in PDF | Author Info
This study presents new models for predicting bilberry and cowberry yields from site and stand characteristics. These models enable one to evaluate the future states of forests in terms of berry yields. The modelling data consisted of visual field estimates of site and tree stand characteristics, as well as berry yields from 627 forest stands. Berry yields were estimated using a scale from 0 to 10. Using these data, models were prepared which predict the berry yield scores from those site and stand characteristics which are usually known in forest planning calculations. The model predictions correlated positively and often quite strongly with earlier models. The results were in line with previous studies on the effects of site and tree cover on berry production. According to the models, sites of medium and rather poor fertility produce the highest bilberry yields. Increasing tree height increases, and the basal area of spruce and proportion of deciduous trees decrease, bilberry yield. With mineral soils, cowberry yields are best on poor sites. A high proportion of pine improves cowberry yields. The yields are the highest in open areas and very young stands, on the one hand, and in sparsely populated stands of large and old trees, on the other hand. In pine swamps, the yields are best on rather poor sites. Increasing basal area of deciduous trees decreases cowberry yields.
  • Ihalainen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: marjut.ihalainen@forest.joensuu.fi (email)
  • Pukkala, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: tp@nn.fi
article id 598, category Research article
A. Maarit I. Kallio. (2001). Interdependence of the sawlog, pulpwood and sawmill chip markets: an oligopsony model with an application to Finland. Silva Fennica vol. 35 no. 2 article id 598. https://doi.org/10.14214/sf.598
Keywords: wood market; oligopsony; forest industry
Abstract | View details | Full text in PDF | Author Info
The interdependence of the markets for pulpwood, sawlogs and sawmill chips is analysed using a short-run model, which accommodates the alternative competition structures of wood buyers. We propose that imperfect competition in the pulpwood market tends to make the sawmills owned by the pulp and paper companies larger than the independent ones, even in the absence of transactional economies of integration. The impact of the wood market competition pattern on the profits of the forest owners and forest industry firms depends upon a firm-capacity structure, wood supply elasticities, and business cycles in the output markets. The numerical application of the model to the Finnish softwood market suggests that inflexibility of production capacities tends to make the wood demand rather insensitive with respect to price. Only the large firms, which all produce both pulp and sawnwood, may have oligopsony power under some conditions. Integrated production can increase competition in the sawlog market via the wood chip market.
  • Kallio, Helsinki School of Economics, Department of Economics and Management Science, P.O. Box 1210, FIN-00101 Helsinki E-mail: maarit.kallio@hkkk.fi (email)
article id 607, category Research article
Jurkka Kuusipalo. (2001). Plastic coating of plywood using extrusion technique. Silva Fennica vol. 35 no. 1 article id 607. https://doi.org/10.14214/sf.607
Keywords: plywood; thermoplastics; polymer; polyethylene; polypropylene; extrusion coating; adhesion
Abstract | View details | Full text in PDF | Author Info
The target was to study and develop industrially suitable methods to apply thermoplastic coatings on plywood. Typically, wear and climatic resistance for wooden sheets, such as chip board and plywood, is achieved by thermosetting resin coating (e.g. phenol-formaldehyde). However, economical and environmental issues are driving towards thermoplastic coatings (e.g. polyethylene) in such products. Several technologies, such as film gluing and laminating, have been introduced, but the costs and processing are limiting factors. This study concentrates on direct coating of plywood with extruded molten plastic film, in other words extrusion coating of plywood. This technique provides fast coating process and cheap raw materials. In the study it was found that extrusion coating of plywood is difficult. The high heat energy of the molten plastic causes moisture evaporation of the top veneer, and the only possible escape direction of the evaporated moisture is through the plastic, which causes bubbling in the plastic coating. Another disadvantage of the plywood is its rigidity, which limits the development of the process. In this work, a new technique was applied for coating the flexible veneers with typical extrusion coating equipment, where the escape of the evaporated moisture was possible through the top veneer to the atmosphere. Another main issue was to reach sufficient adhesion between plastic and plywood. Target was achieved using either monolayer polyethylene (PE-LD) or 2-layer polypropylene/adhesion polymer plastic coatings.
  • Kuusipalo, Tampere University of Technology, Institute of Paper Converting, Korkeakoulunkatu 4 C, P.O. Box 541, FIN-33720 Tampere, Finland E-mail: jurkka@cc.tut.fi (email)
article id 622, category Research article
Håkan Lindström. (2000). Intra-tree models of basic density in Norway spruce as an input to simulation software. Silva Fennica vol. 34 no. 4 article id 622. https://doi.org/10.14214/sf.622
Keywords: Picea abies; wood density; image analysis; basic density; growth conditions
Abstract | View details | Full text in PDF | Author Info
Basic density is said to influence aspects of conversion, properties, and end-use of forest products. Consequently, it is argued that accurate models of basic density variation, within and between trees, could be used to improve the utilisation of wood as an industrial raw material. The objective of the present study was to develop basic density models based on Norway spruce trees, that could be used within a model system for conversion simulation studies. Nineteen stands of Norway spruce (Picea abies (L.) Karst.) were selected throughout Sweden. Based on dbh, two small, two moderate, and two large timber trees were taken from each stand. Dbh varied between 180–470 mm, tree height between 17–34 m, and total age between 51–152 years. Each selected tree was cross-cut into logs; discs were prepared from the butt end of each log and from the top end of the top log. Computed tomography scanning and image analysis were used to determine basic density and growth ring development on sampled discs. Basic density development in 20-mm segments from pith outwards was modelled in models based on ring width, tree and growth condition data. The resulting models had an adjusted R2 of 0.37–0.51 and a RMSE of 37–41 kg/m3.
  • Lindström, University of Canterbury, School of Forestry, Private Bag 4800, Christchurch, New Zealand E-mail: lindstromhakan@netscape.net (email)
article id 630, category Research article
S. Samarasinghe, G. D. Kulasiri. (2000). Displacement fields of wood in tension based on image processing: Part 2. Crack-tip displacements in mode-I and mixed-mode fracture. Silva Fennica vol. 34 no. 3 article id 630. https://doi.org/10.14214/sf.630
Keywords: wood; digital image correlation; fracture modes; orthotropic fracture; tip displacement
Abstract | View details | Full text in PDF | Author Info
Near tip displacement fields for tensile loaded cracked rubber and wood with a crack parallel-, perpendicular-to-grain, and a parallel-to-grain crack inclined 30°, 45°, and 60° to the load axis were obtained from digital image correlation (DIC). Theoretical displacements were also obtained for rubber and wood using isotropic and orthotropic fracture theory, respectively. The results showed that DIC can reveal fine details of the nature of displacements and the influences of crack tip in both rubber and wood. Experimental crack tip displacements for wood compare well with theory; particularly, when load is perpendicular-to-grain. Some anomalies were found in the tip displacements in the direction of the tracheids due to the unique nature of their behaviour not accounted for by theory. Mixed-mode crack tip displacement fields for wood clearly showed the increasing influence of crack angle on the displacements, and the displacements perpendicular to crack compared very well with theory. The displacements parallel to crack showed some variations owing to the involvement of tracheids.
  • Samarasinghe, Lincoln University, Appl. Computing, Mathematics and Statistics Group, P.O. Box 84, Canterbury, New Zealand E-mail: ss@nn.nz
  • Kulasiri, Lincoln University, Appl. Computing, Mathematics and Statistics Group, P.O. Box 84, Canterbury, New Zealand E-mail: kulasird@tui.lincoln.ac.nz (email)
article id 629, category Research article
S. Samarasinghe, G. D. Kulasiri. (2000). Displacement fields of wood in tension based on image processing: Part 1. Tension parallel- and perpendicular- to grain and comparisons with isotropic behaviour. Silva Fennica vol. 34 no. 3 article id 629. https://doi.org/10.14214/sf.629
Keywords: wood; deformation profiles; image processing; micro-structure
Abstract | View details | Full text in PDF | Author Info
Displacement fields for tensile loaded rubber and wood in parallel- and perpendicular-to-grain were obtained from digital image correlation. The results showed that the digital image correlation can reveal fine details of the nature of displacements in both rubber and wood. It was found that when load is perpendicular-to-grain, the lignin matrix produces uniform displacement fields similar to that of isotropic rubber. Uniform displacement fields also observed when lignin is involved in contraction due to Poisson effect in parallel-to-grain tension. However, when tracheids carry the load in parallel-to-grain loading, or are compressed in perpendicular-to-grain loading, a complex displacement pattern distorted by internal shear stress and slippage is produced.
  • Samarasinghe, Lincoln University, Appl. Computing, Mathematics and Statistics Group, P.O. Box 84, Canterbury, New Zealand E-mail: ss@nn.nz
  • Kulasiri, Lincoln University, Appl. Computing, Mathematics and Statistics Group, P.O. Box 84, Canterbury, New Zealand E-mail: kulasird@tui.lincoln.ac.nz (email)
article id 627, category Research article
Joseph Buongiorno, Audra Kolbe, Mike Vasievich. (2000). Economic and ecological effects of diameter-limit and BDq management regimes: simulation results for northern hardwoods. Silva Fennica vol. 34 no. 3 article id 627. https://doi.org/10.14214/sf.627
Keywords: diversity; hardwoods; simulation; uneven-aged management; economics; mixed-species stands
Abstract | View details | Full text in PDF | Author Info
The long-term financial and ecological effects of diameter-limit regimes and basal-area-diameter-q-ratio (BDq) regimes were compared by simulation in the case of northern hardwood forests. Varying the cutting cycle between 10 and 20 years had little effect on returns or stand structure. A 28-cm diameter-limit cut gave the highest production and financial returns, and the highest species diversity, but considerably lower size diversity. A 38-cm diameter-limit cut and a heavy BDq selection harvest gave high returns, while maintaining high levels of diversity. On lands of equal site quality, Michigan’s stands were more productive than Wisconsin’s. The results suggest that it is possible to manage northern hardwood stands sustainably with diameter-limit cuts, combined with removal of poorly performing understory trees. Adjusting the diameter limit gave rise to stands similar in productivity and structure to those obtained by BDq cutting regimes. Given their simplicity of implementation and monitoring, more attention should be given to diameter-limit cutting regimes, with attendant stand improvement measures, as a practical means for uneven-aged management of northern hardwoods.
  • Buongiorno, Department of Forest Ecology and Management, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53705, USA E-mail: Jbuongio@facstaff.wisc.edu (email)
  • Kolbe, Department of Forest Ecology and Management, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53705, USA E-mail: ak@nn.us
  • Vasievich, USDA Forest Service, North Central Forest Experiment Station, 1407 S. Harrison Road, Suite 220, East Lansing, MI 48823, USA E-mail: mv@nn.us
article id 636, category Research article
Tuula Nuutinen, Hannu Hirvelä, Jari Hynynen, Kari Härkönen, Hannu Hökkä, Kari T. Korhonen, Olli Salminen. (2000). The role of peatlands in Finnish wood production – an analysis based on large-scale forest scenario modelling. Silva Fennica vol. 34 no. 2 article id 636. https://doi.org/10.14214/sf.636
Keywords: peatlands; MELA; wood production; forest scenario modelling
Abstract | View details | Full text in PDF | Author Info
Using the Finnish MELA model, a set of scenarios were produced and used to map the possibilities and risks surrounding the utilisation of peatlands in wood production in Finland. One of the scenarios was an estimate of allowable-cut calculated by maximising the net present value of the future revenues using a four per cent interest rate subject to non-decreasing flow of wood, saw logs and net income over a 50-year period, and net present value after the 50 year period greater or equal than in the beginning. The estimate for maximum regionally sustained removal in 1996–2005 was 68 million m3 per year – approaching 74 million m3 during the next decades. In this scenario, 14 per cent of all cuttings during the period 1996–2005 would be made on peatlands, which comprise ca. 31 per cent of the total area of forestry land. By the year 2025, the proportion of peatland cuttings would increase to over 20 per cent. The increase in future cutting possibilities on peatlands compensated for a temporary decrease in cuttings and growing stock on mineral soils. The allowable-cut effect was especially pronounced in northern Finland, where peatlands play an important role in wood production. In addition, the sensitivity of cutting possibilities for assumptions related to growth and price were analysed. The estimate of maximum sustainable yield as defined here seems to be fairly robust on the whole, except in northern Finland where the cutting scenarios were sensitive to the changes in the price of birch pulpwood. The proportion of peatland stands that are profitable for timber production depends on the interest rate: the higher the rate of interest the less peatland stands are thinned. The effect of cutting profile on future logging conditions and resulting costs were analysed in two forestry centres. If clear cuttings on mineral soils are to be cut first, an increase in future logging costs is inevitable.
  • Nuutinen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: tuula.nuutinen@metla.fi (email)
  • Hirvelä, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: hh@nn.fi
  • Hynynen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: jh@nn.fi
  • Härkönen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: kh@nn.fi
  • Hökkä, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: hh@nn.fi
  • Korhonen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: ktk@nn.fi
  • Salminen, Finnish Forest Research Institute, Joensuu Research Station, P.O. Box 68, FIN-80101 Joensuu, Finland E-mail: os@nn.fi
article id 643, category Research article
Pekka Eskelinen, Harri Eskelinen. (2000). A K-band microwave measuring system for the analysis of tree stems. Silva Fennica vol. 34 no. 1 article id 643. https://doi.org/10.14214/sf.643
Keywords: microwave measurements; wood analysis; knot detection; stem quality evaluation
Abstract | View details | Full text in PDF | Author Info
The internal structure of growing trees and freshly cut logs can be characterized in real time by analysing the transmission and reflection of Ku- or K-band microwave energy injected with a horizontal polarization towards the material. Information about the moisture content, material bends, number and location of knots and sections of spoiled wood e.g. due to insects can be gathered in real time. Most sensitive test parameters are attenuation, group delay and the rotation of a linearly polarized wavefront. A simultaneous recording of reflection reduces errors caused by non-significant surface deformations. The spatial resolution, humidity equalization and noise immunity can be improved by applying a wideband frequency modulation. Commercial building blocks supplemented with a special antenna arrangement give possibilities also for the rough harvester environment.
  • Eskelinen, Lappeenranta University of Technology, Department of Electrical Engineering, P.O. Box 20, FIN-53851 Lappeenranta, Finland E-mail: ari.eskelinen@pp.inet.fi (email)
  • Eskelinen, Lappeenranta University of Technology, Department of Electrical Engineering, P.O. Box 20, FIN-53851 Lappeenranta, Finland E-mail: he@nn.fi
article id 665, category Research article
Kari Kangas. (1999). Trade of main wild berries in Finland. Silva Fennica vol. 33 no. 2 article id 665. https://doi.org/10.14214/sf.665
Keywords: imports; bilberry; non-wood forest products; trade; lingonberry; exports
Abstract | View details | Full text in PDF | Author Info
The price trends and markets of the main wild berries, bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.), were analysed in this study, which covered both domestic use of berries, imports and exports. The periods considered were for bilberries from 1988 to 1997 and for lingonberries from 1979 to 1994. The results indicated that both exports and imports have increased and domestic berries have lost their market share to imports in domestic use. One possible explanation for this trend was found in price development. Both export and import prices have decreased, but export price has still been higher than the import price. Simultaneously the domestic price has decreased the fastest. The formation of the price of lingonberries paid to the pickers in the organised domestic markets was studied with a regression model. The results indicated that domestic price was negatively dependent on the amounts of lingonberries demanded in the domestic markets and positively dependent on the export price. Correlation analysis gave evidence on the same kind of relations concerning bilberries.
  • Kangas, University of Joensuu, Faculty of Forestry, P.O. Box 111, FIN-80101 Joensuu, Finland E-mail: kari.kangas@forest.joensuu.fi (email)
article id 662, category Research article
Lars Björklund. (1999). Identifying heartwood-rich stands or stems of Pinus sylvestris by using inventory data. Silva Fennica vol. 33 no. 2 article id 662. https://doi.org/10.14214/sf.662
Keywords: Pinus sylvestris; sapwood; heartwood; wood utilisation
Abstract | View details | Full text in PDF | Author Info
Variations in heartwood percentage, heartwood radius and sapwood width, within and between stands of Scots pine (Pinus sylvestris L.), were analysed using a database of 198 CT-scanned (computer tomography) stems from 33 research plots (stands) throughout Sweden. Heartwood percentage varied greatly both between individual trees and between stands, and correlated poorly to site, stand and tree variables. This implies that it seems unfeasible to identify heartwood-rich stands or stems, e.g., for production of heartwood products, by using inventory data. Heartwood formation expressed as the number of new heartwood rings formed each year was found to increase with increasing cambial age, from about 0.5 rings per year at a cambial age of 45 years, to about 0.8 rings per year at a cambial age of 115 years.
  • Björklund, Swedish University of Agricultural Sciences, Department of Forest Management and Products, S-750 07 Uppsala, Sweden E-mail: lars.bjorklund@sh.slu.se (email)
article id 675, category Research article
Per Linder, Peter Jonsson, Mats Niklasson. (1998). Tree mortality after prescribed burning in an old-growth Scots pine forest in northern Sweden. Silva Fennica vol. 32 no. 4 article id 675. https://doi.org/10.14214/sf.675
Keywords: forest management; coarse woody debris; tree mortality; nature conservation; forest fire; dead trees
Abstract | View details | Full text in PDF | Author Info
Tree mortality and input of dead trees were studied after a prescribed burning in a forest reserve in northern Sweden. The stand was a multi-layered old-growth forest. The overstorey was dominated by Scots pine (Pinus sylvestris L.) and the understorey consisted of mixed Scots pine and Norway spruce (Picea abies L. Karst.). Ground vegetation was dominated by ericaceous dwarf-shrubs and feathermosses. The stand has been affected by six forest fires during the last 500 years. The prescribed burning was a low intensity surface fire that scorched almost 90% of the ground. Tree mortality for smaller pines and spruces (DBH < 10 cm) was over 80% in the burned parts of the reserve. For larger pines, 10–50 cm DBH, mortality showed a decreasing trend with increasing diameter, from 14% in class 10–20 cm DBH to 1.4% in class 40–50 cm DBH. However, pines with DBH ≥ 50 cm had a significantly higher mortality, 20%, since a high proportion of them had open fire scars containing cavities, caused by fungi and insects, which enabled the fire to burn inside the trunks and hollow them out. The fire-induced mortality resulted in a 21 m3 ha–1 input of dead trees, of which 12 m3 ha–1 consisted of trees with DBH ≥ 30 cm. An increased mortality among larger trees after low-intensity fires has not previously been described in Fennoscandian boreal forests, probably owing to a lack of recent fires in old-growth stands. However, since large pines with open fire scars were once a common feature in the natural boreal forest, we suggest that this type of tree mortality should be mimicked in forestry practices aiming to maintain and restore natural forest biodiversity.
  • Linder, Department of Forest Vegetation Ecology, SLU, S-901 83 Umeå, Sweden E-mail: pl@nn.se (email)
  • Jonsson, Department of Forest Vegetation Ecology, SLU, S-901 83 Umeå, Sweden E-mail: pj@nn.se
  • Niklasson, Southern Swedish Forest Research Centre, SLU, Box 49, S-230 53 Alnarp, Sweden E-mail: mn@nn.se
article id 700, category Research article
Riitta H. Hänninen. (1998). Exchange rate changes and the Finnish sawnwood demand and price in the UK market. Silva Fennica vol. 32 no. 1 article id 700. https://doi.org/10.14214/sf.700
Keywords: exchange rate; export demand; Johansen’s cointegration method; pass-through; sawnwood price; United Kingdom
Abstract | View details | Full text in PDF | Author Info
This paper examines the long-run influence of exchange rate changes on the Finnish sawnwood price in the United Kingdom (UK) using quarterly data for the period 1978–1994. The degree of influence was measured by a pass-through coefficient (PT) obtained from a markup pricing relation of a system model. The model, which included export demand and price equations, was estimated with the cointegration method of Johansen. The results indicated a large PT, which means that exchange rate changes are reflected almost proportionately in Finnish export price expressed in pounds sterling. Thus, the Finnish price of sawnwood in pounds has lowered as a result of depreciation of the Finnish markka (FIM). This has improved Finnish competitiveness and market share in the UK. Appreciation of the FIM has had the opposite effect. It seems that Finnish exporters have made use of depreciations and devaluations of the FIM to maintain and increase their market shares but not necessarily their markups. For Finland, which is in the process of joining the European economic and monetary union (EMU), knowing the size of the PT is also important in assessing the economic impact of membership.
  • Hänninen, Forest Research Institute, Helsinki Research Centre, Unioninkatu 40 A, 00170 Helsinki, Finland E-mail: riitta.hanninen@metla.fi (email)

Category : Climate resilient and sustainable forest management – Review article

article id 23057, category Climate resilient and sustainable forest management – Review article
Ane Christensen Tange, Hanne K. Sjølie, Gunnar Austrheim. (2024). Effectiveness of conservation measures to support biodiversity in boreal timber-production forests. Silva Fennica vol. 58 no. 2 article id 23057. https://doi.org/10.14214/sf.23057
Keywords: forestry; sustainable forest management; dead wood enhancement; forest certification; green tree retention; riparian buffer zone
Highlights: A systematic review of in-situ conservation measures displays that forest biodiversity levels are largely maintained upon harvest with conservation measures compared to unlogged forest; The type of control impacts the frequency of positive, not significant and negative observations; The relatively few significant results restrain distinct conclusions on the effectiveness of the assessed conservation measures to support biodiversity.
Abstract | Full text in HTML | Full text in PDF | Author Info

Large parts of the boreal forest ecosystems have been greatly affected by human use, and the current timber-oriented forest management practice that dominates boreal forests is proven to cause biodiversity and ecosystem services declines. These negative effects are mitigated in various ways, including in-situ measures implemented upon harvest. The measures comprise trade-offs between economic and ecological aims; thus, requiring solid knowledge of their effectiveness. However, comprehensive literature review of the effectiveness of such measures is scarce. We aim to fill part of this void by reviewing the scientific literature that have gauged effects of four in-situ conservation measures: green tree retention (GTR), patch retention (PR), dead wood retention (DW) and riparian buffer zones (RB). Two outcomes were considered, species richness and species abundance across taxa.

From a total of 3012 initial papers, 48 met our inclusion criteria that generated 238 unique results. Results were grouped according to control. 178 studies used mature, unlogged forest as control. Out of those, 68% of the findings were not significant, i.e., suggesting no significant impact of harvest with biodiversity measures on species richness and species abundance compared to no harvest. Eighteen percent of the observations showed negative effects and 14% of the observations showed positive effects compared to no harvest. Sixty studies used harvest with no measures as control, of which 45% showed significant positive effects, meaning that compared to harvest with no measures, harvest with conservation measures has positively effects on species richness and abundance. However, 43% of the studies found no significant effect of the implemented conservation measures compared to harvest with no measures taken.

The relatively few significant results reported restrain distinct conclusions on the effectiveness of the assessed conservation measures, but some degree of conservation measure is likely to have positive effects on biodiversity in timber-production forest. However, the scientific basis does not allow for pointing to threshold levels. Higher transparency of study design and statistical results would allow us to include more studies. There is a clear need for more research of effectiveness of common conservation measures in timber-production forests in order to strengthen the knowledge basis. In particular, there are few studies that employ harvest without any conservation measure as control. This is pivotal knowledge for forest managers as well as for policymakers for preserving biodiversity and the ecosystems in forest.

  • Tange, Inland Norway University of Applied Sciences, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Department of Forestry and Wildlife Management, Evenstad, Norway; Glommen Mjøsen Skog SA, Elverum, Norway ORCID https://orcid.org/0009-0001-3145-8159 E-mail: ane.tange@inn.no (email)
  • Sjølie, Inland Norway University of Applied Sciences, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Department of Forestry and Wildlife Management, Evenstad, Norway ORCID https://orcid.org/0000-0001-8099-3521 E-mail: hanne.sjolie@inn.no
  • Austrheim, University Museum Norwegian University of Science and Technology, Department of Natural History, Trondheim, Norway ORCID https://orcid.org/0000-0002-3909-6666 E-mail: gunnar.austrheim@ntnu.no

Category : Review article

article id 22018, category Review article
Felipe de Miguel-Díez, Thomas Purfürst, Mauricio Acuna, Eduardo Tolosana-Esteban, Tobias Cremer. (2023). Estimation of conversion factors for wood stacks in landings and their influencing parameters: a comprehensive literature review for America and Europe. Silva Fennica vol. 57 no. 1 article id 22018. https://doi.org/10.14214/sf.22018
Keywords: log properties; roundwood measurement; roundwood purchase; stack properties; wood supply chain
Highlights: Midpoint diameter, stacking quality, crookedness, log length, delimbing quality and bark thickness strongly influence the conversion factors; In Europe and America, a total of 48 methods were developed to estimate the conversion factors of wood stacks; The conversion factors should be estimated for each wood assortment and tree species.
Abstract | Full text in HTML | Full text in PDF | Author Info
In commercial transaction of stacked roundwood, the estimation of the stack net volume plays a key role. One generalized method to determine the net volume is using conversion factors that relate the gross and net volumes. In this literature review the developed methods to estimate the conversion factors as well as their influencing parameters were analyzed based on 153 references from America and Europe. According to the results, 48 different methods (including their variants) for estimating the conversion factors were developed. The newest methods enabled their accurate determination inexpensively, e.g., photo-optical methods or 3D simulation models. The analyzed references revealed that 30 parameters influence the conversion factors. Based on this comprehensive review, each stakeholder involved in the roundwood supply chain can know which method is used for estimating the conversion factors in the analyzed territories and which influencing parameters should be considered when purchasing roundwood in order to accurately assess the solid wood content in the stacks.
  • de Miguel-Díez, Eberswalde University for Sustainable Development, Department of Forest Utilization and Timber Markets, Eberswalde, Germany; University of Freiburg, Chair of Forest Operations, Freiburg, Germany ORCID https://orcid.org/0000-0002-3800-7449 E-mail: felipe.diez@hnee.de
  • Purfürst, University of Freiburg, Chair of Forest Operations, Freiburg, Germany ORCID https://orcid.org/0000-0001-9661-0193 E-mail: thomas.purfuerst@foresteng.uni-freiburg.de
  • Acuna, University of the Sunshine Coast, Forest Research Institute, Sunshine Coast, Queensland, Australia E-mail: macuna@usc.edu.au
  • Tolosana-Esteban, Universidad Politécnica de Madrid, E.T.S.I. Montes, Forestal y del Medio Natural, Madrid, Spain ORCID https://orcid.org/0000-0003-2561-0342 E-mail: eduardo.tolosana@upm.es
  • Cremer, Eberswalde University for Sustainable Development, Department of Forest Utilization and Timber Markets, Eberswalde, Germany ORCID https://orcid.org/0000-0001-7866-944X E-mail: Tobias.Cremer@hnee.de
article id 10609, category Review article
Jaakko Jussila, Emil Nagy, Katja Lähtinen, Elias Hurmekoski, Liina Häyrinen, Cecilia Mark-Herbert, Anders Roos, Ritva Toivonen, Anne Toppinen. (2022). Wooden multi-storey construction market development – systematic literature review within a global scope with insights on the Nordic region. Silva Fennica vol. 56 no. 1 article id 10609. https://doi.org/10.14214/sf.10609
Keywords: sustainability; construction industry; consumer; forest-wood value chain; municipality; urbanization
Highlights: Enabling factors for WMC market diffusion include benefits from cost-efficiency gains from prefabrication and industrialization and perceived sustainability benefits; Inexperience of using wood, and path dependencies to use concrete and steel in multi-storey building are the key barriers for mainstreaming WMC market development; More research is needed on the development in the wood construction value-chains to challenge the dominant concrete-based construction regime in the housing markets.
Abstract | Full text in HTML | Full text in PDF | Author Info

Climate change sets high pressures on the construction industry to decrease greenhouse gas emissions. Due to the carbon storage properties and potential to use renewable resources efficiently, wooden multi-storey construction (WMC) is an interesting alternative for the construction industry to enhance sustainable development combined with the aesthetic and well-being benefits of wood perceived among many consumers. For forest industry firms, industrial wood construction is a possibility to seek for business opportunities and bring socio-economic benefits for local economies. Despite positive drivers, WMC still remains a niche even in the forest-rich countries.The purpose of our study is to add understanding on the WMC market development by conducting a systematic literature analysis on international peer-reviewed studies from the past 20 years. Our special focus is on the role of WMC in the housing markets studied from the perspectives of the demand, supply and local governance factors. As specific aims, we 1) synthesize the key barriers and enabling factors for the WMC market growth; 2) identify the actors addressed in the existing studies connected to the WMC market development, and 3) summarize research methods and analytical approaches used in the previous studies. As a systematic method to make literature searches in Web of Science and Scopus for years 2000–2020, we employed PRISMA guidelines. By using pre-determined keywords, our searches resulted in a sample of 696 articles, of which 42 full articles were after selection procedure included in-depth content analysis. Our results showed cost-efficiency gains from industrialized prefabrication and perceived sustainability benefits by consumers and architects enabled a WMC market diffusion. The lack of experiences on the WMC, and path dependencies to use concrete and steel continue to be key barriers for increased WMC. Although our research scope was the global WMC market development, most of the literature concerned the Nordic region. The key actors covered in the literature were businesses (e.g., contractors, manufacturers and architects) involved in the wood construction value-chains, while residents and actors in the local governance were seldomly addressed. Currently, case studies, the use of qualitative data sets and focus on the Nordic region dominate the literature. This hinders the generalizability of findings in different regional contexts. In the future, more research is needed on how sustainability-driven wood construction value-chains are successfully shaping up in different geographical regions, and how they could challenge the dominant concrete-based construction regime.

  • Jussila, University of Helsinki, Department of Forest Sciences, P.O. Box 4, FI-00014 University of Helsinki, Finland E-mail: jaakko@jussila.fi (email)
  • Nagy, Swedish University of Agricultural Sciences, Department of Forest Economics, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: emil.nagy@slu.se
  • Lähtinen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, P.O. Box 2, FI-00791 Helsinki, Finland E-mail: katja.lahtinen@luke.fi
  • Hurmekoski, University of Helsinki, Department of Forest Sciences, P.O. Box 4, FI-00014 University of Helsinki, Finland E-mail: elias.hurmekoski@helsinki.fi
  • Häyrinen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, P.O. Box 2, FI-00791 Helsinki, Finland E-mail: liina.hayrinen@luke.fi
  • Mark-Herbert, Swedish University of Agricultural Sciences, Department of Forest Economics, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: cecilia.mark-herbert@slu.se
  • Roos, Swedish University of Agricultural Sciences, Department of Forest Economics, P.O. Box 7060, SE-750 07 Uppsala, Sweden E-mail: anders.roos@slu.se
  • Toivonen, University of Helsinki, Department of Forest Sciences, P.O. Box 4, FI-00014 University of Helsinki, Finland E-mail: ritva.toivonen@helsinki.fi
  • Toppinen, University of Helsinki, Department of Forest Sciences, P.O. Box 4, FI-00014 University of Helsinki, Finland E-mail: anne.toppinen@helsinki.fi
article id 446, category Review article
Guntis Brumelis, Bengt Gunnar Jonsson, Jari Kouki, Timo Kuuluvainen, Ekaterina Shorohova. (2011). Forest naturalness in northern Europe: perspectives on processes, structures and species diversity. Silva Fennica vol. 45 no. 5 article id 446. https://doi.org/10.14214/sf.446
Keywords: disturbances; dead wood; natural forest; biological diversity
Abstract | View details | Full text in PDF | Author Info
Saving the remaining natural forests in northern Europe has been one of the main goals to halt the ongoing decline of forest biodiversity. To facilitate the recognition, mapping and efficient conservation of natural forests, there is an urgent need for a general formulation, based on ecological patterns and processes, of the concept of “forest naturalness”. However, complexity, structural idiosyncracy and dynamical features of unmanaged forest ecosystems at various spatio-temporal scales pose major challenges for such a formulation. The definitions hitherto used for the concept of forest naturalness can be fruitfully grouped into three dimensions: 1) structure-based concepts of natural forest, 2) species-based concepts of natural forest and 3) process-based concepts of natural forest. We propose that explicit and simultaneous consideration of all these three dimensions of naturalness can better cope with the natural variability of forest states and also aid in developing strategies for forest conservation and management in different situations. To become operational, criteria and indicators of forest naturalness need to integrate the three dimensions by combining species (e.g. red-listed-, indicator- and umbrella species) with stand and landscape level structural features that are indicative of disturbance and succession processes.
  • Brumelis, Faculty of Biology, University of Latvia, Kronvalda bulv. 4, Riga, LV-1586, Latvia; E-mail: guntis.brumelis@lu.lv (email)
  • Jonsson, Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, Sundsvall, Sweden E-mail: bgj@nn.se
  • Kouki, School of Forest Sciences, University of Eastern Finland, Joensuu, Joensuu E-mail: jk@nn.fi
  • Kuuluvainen, Department of Forest Sciences, University of Helsinki, Finland E-mail: tk@nn.fi
  • Shorohova, Saint-Petersburg State Forest Academy, Saint-Petersburg, Russia & Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland E-mail: es@nn.ru
article id 38, category Review article
Matieu Henry, Nicolas Picard, Carlo Trotta, Raphaël J. Manlay, Riccardo Valentini, Martial Bernoux, Laurent Saint-André. (2011). Estimating tree biomass of sub-Saharan African forests: a review of available allometric equations. Silva Fennica vol. 45 no. 3B article id 38. https://doi.org/10.14214/sf.38
Keywords: aboveground biomass; databases; inventories; models; Tier method; wood specific gravity
Abstract | View details | Full text in PDF | Author Info
In response to the growing interest in estimating carbon stocks in forests, available allometric equations have been compiled for sub-Saharan Africa. Tree, sprout and stand volume and biomass equations were reviewed. The 850 equations and 125 related references were incorporated into an open-access database on the Carboafrica website (http://www.carboafrica.net). The collected information provides a basic tool for the estimation of biomass and carbon stocks and other purposes, such as bioenergy and fodder supply assessment. A Tier-method approach was developed to illustrate the possible use of the equations. Current available biomass expansion factors that are used to convert a volume to the total aboveground biomass appear to be limited; incomplete species-specific allometric equations are preferred to generalised equations. The analysis of the database highlighted important gaps in available tools to assess forest carbon stocks and changes in these stocks. A quality control assessment revealed that 22% of the equations were misreported and recommendations were proposed to guide further research. Further statistical analyses, such as the Bayesian approach, would help to produce more accurate biomass estimates.
  • Henry, IRD, UMR Eco&Sols, Montpellier SupAgro, 2 place Viala, 34060 Montpellier, France; Di.S.A.F.Ri, Università degli Studi della Tuscia, Viterbo, Italy; and AgroParisTech-ENGREF, GEEFT, Montpellier, France E-mail: henry@unitus.it (email)
  • Picard, CIRAD, Montpellier, France E-mail: np@nn.fr
  • Trotta, Di.S.A.F.Ri, Università degli Studi della Tuscia, Viterbo, Italy E-mail: ct@nn.it
  • Manlay, IRD, UMR Eco&Sols, Montpellier SupAgro, 2 place Viala, 34060 Montpellier, France; and AgroParisTech-ENGREF, GEEFT, Montpellier, France E-mail: rjm@nn.fr
  • Valentini, Di.S.A.F.Ri, Università degli Studi della Tuscia, Viterbo, Italy E-mail: rv@nn.it
  • Bernoux, IRD, UMR Eco&Sols, Montpellier SupAgro, 2 place Viala, 34060 Montpellier, France E-mail: mb@nn.fr
  • Saint-André, CIRAD, Montpellier, France; and INRA, UR1138, Biogeochimie des Ecosystèmes Forestiers, Champenoux, France E-mail: lsa@nn.fr
article id 312, category Review article
Katja Lähtinen. (2007). Linking resource-based view with business economics of woodworking industry: earlier findings and future insights. Silva Fennica vol. 41 no. 1 article id 312. https://doi.org/10.14214/sf.312
Keywords: strategy; competitiveness; enterprises; resources; woodworking firms
Abstract | View details | Full text in PDF | Author Info
The business environment and sources of competitiveness in the woodworking industry have changed notably since the 1990s. Wood products are traded globally, and with the increase of trade, abundant forest resources are no longer the main source of sustainable competitiveness. Competition within the woodworking industry is increasing both between European and non-European enterprises, as well as within the EU. Capability to create value-added, making rational strategic choices, and creative usage of intangible and tangible resources have been emphasized as crucial for sustaining woodworking industry competitiveness in higher cost-level countries. Resource-based view (RBV) defines the availability of intangible assets, capabilities and tangible resources, and their heterogeneous combination to form the basis for company success. The objective of this review is to examine the possibilities to employ the RBV to the study of the woodworking industry by combining existing empirical results of the factors of companies’ competitiveness with assessment of the RBV. In the existing literature, strategies implemented in woodworking companies have been approached rather widely, while the role of intangible and tangible resources in building firm-level success has received less focus. In addition, a significant gap exists in linking firms’ financial accounting information with empirical data on their resource-usage and business strategies. In future studies, more information of the effects of these strategic elements on the actual business success of the firms would be needed.
  • Lähtinen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: katja.lahtinen@metla.fi (email)
article id 390, category Review article
Bengt Gunnar Jonsson, Nicholas Kruys, Thomas Ranius. (2005). Ecology of species living on dead wood – lessons for dead wood management. Silva Fennica vol. 39 no. 2 article id 390. https://doi.org/10.14214/sf.390
Keywords: forest management; saproxylic species; coarse woody debris; woodland key habitats; landscape planning; Fennoscandian forests; epixylic species
Abstract | View details | Full text in PDF | Author Info
Dead wood has been identified as a crucial component for forest biodiversity. Recent research has improved our understanding of habitat relations for many species associated with dead wood. However, the consequences for forest management are yet to be explored. In this review we build upon the growing volume of studies on dead wood dependent species, the dynamics of dead wood and ecological theory in order to identify the challenges for forest management at the landscape level. The review has a Fennoscandian focus, but the problems and challenges are similar in many forest ecosystems. We argue that it is necessary to 1) counteract the current shortage in availability of dead wood, 2) concentrate planning at the landscape level in order to minimize isolation and reduce edge effects, 3) create a variety of dead wood types, and 4) utilise available quantitative analytical tools. This calls for new approaches to management that to a large extent includes available knowledge, and to find platforms for planning forested landscapes with diverse holdings.
  • Jonsson, Mid Sweden University, Dept of Natural Sciences, SE-851 70 Sundsvall, Sweden E-mail: bengt-gunnar.jonsson@miun.se (email)
  • Kruys, SLU, Dept of Forest Resource Management and Geomatics, SE-901 83 Umeå, Sweden E-mail: nk@nn.se
  • Ranius, SLU, Dept of Entomology, SE-750 07 Uppsala, Sweden E-mail: tr@nn.se
article id 688, category Review article
John A. Stanturf, Callie J. Schweitzer, Emile S. Gardiner. (1998). Afforestation of marginal agricultural land in the Lower Mississippi River Alluvial Valley, U.S.A. Silva Fennica vol. 32 no. 3 article id 688. https://doi.org/10.14214/sf.688
Keywords: Populus deltoides; bottomland hardwoods; direct-seeding; Liquidambar styraciflua; Fraxinus pennsylvanica; Quercus nuttallii; Quercus nigra
Abstract | View details | Full text in PDF | Author Info
Afforestation of marginal agricultural land in the Lower Mississippi Alluvial Valley (LMAV) relies on native species, planted mostly in single-species plantations. Hard mast species such as oak and pecan are favored for their value to wildlife, especially on public land. Successful afforestation requires an understanding of site variation within floodplains and matching species preferences and tolerances to site characteristics, in particular to inundation regimes. Soil physical conditions, root aeration, nutrient availability, and moisture availability during the growing season also must be considered in matching species to site. Afforestation methods include planting seedlings or cuttings, and direct-seeding. Both methods can be done by hand or by machine. If good quality seedlings are planted properly and well cared for before planting, the chances for successful establishment are high but complete failures do occur. Mortality and poor growth are caused by many factors: extended post-planting drought or flooding; poor planting or seeding practices; poor quality seed or seedlings; animal depredation; or herbicide drift from aerial application to nearby cropland. More species can be planted, even on continuously flooded sites. Direct-seeding, while limited to heavy-seeded species (oaks and hickories), costs less than 50% of planting seedlings. Growth varies considerably by soil type; most bottomland hardwoods grow best on silt loam and less well on clay soils. Up to 200 000 ha of land in the LMAV subject to spring and early summer backwater flooding could be afforested over the next decade.
  • Stanturf, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: jstantur/srs_stoneville@fs.fed.us (email)
  • Schweitzer, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: cjs@nn.us
  • Gardiner, USDA Forest Service, Southern Research Station, P.O. Box 227, Stoneville, MS 38776, USA E-mail: esg@nn.us
article id 693, category Review article
Erik G. Ståhl. (1998). Changes in wood and stem properties of Pinus sylvestris caused by provenance transfer. Silva Fennica vol. 32 no. 2 article id 693. https://doi.org/10.14214/sf.693
Keywords: Pinus sylvestris; yield; silviculture; provenance; wood properties; growth phenology
Abstract | View details | Full text in PDF | Author Info
Wood properties focused in forest tree breeding should be of economic importance, have a large total variation and a high heritability. The properties of interest are those that influence the strength and durability of sawn products or the amount and properties of pulp produced. The following wood properties are treated: width of the annual ring, juvenile wood, late wood content, heart wood, tracheid dimensions, basic density, stem straightness and branch diameter. The provenance variation in wood properties can be related to differences in growth phenology. In the northern part of distribution P. sylvestris (L.) provenances transferred a few degrees southwards have a high survival and yield but stem wood production is low. Trees from these provenances will be straight and with few spike knots or other injuries. The shoot elongation period will be short and the temperature sum required for wood formation sufficient. Provenances transferred southwards will form thin annual rings, few and thin branches, little early wood, high basic density and slender tracheids with thick cell walls in comparison to local provenances. An example of the effect of alternative transfers on the yield and wood properties is evaluated. In regions with deviating climatic patterns alternative provenance transfer patterns may be better. The objectives of the land owner should influence the provenance choice. The importance of integrating tree improvement with silvicultural management is discussed with reference to spacing.
  • Ståhl, College of Dalarna, CITU Centre for Industrial Technology and Development, S-781 88 Borlänge, Sweden E-mail: esl@du.se (email)

Category : Research note

article id 23071, category Research note
Mattias Finndin, Per Milberg. (2024). The population development of small trees and shrubs after 100 years of free succession of a wooded meadow in southern Sweden. Silva Fennica vol. 58 no. 1 article id 23071. https://doi.org/10.14214/sf.23071
Keywords: conservation; land-use change; nemoral forest; plants; regrowth; wooded grassland
Highlights: Using a unique map of trees and shrubs from 1937, we estimated the mortality of woody species typical of wooded meadows after management ceased in 1923; Both population size and canopy cover of the studied species had decreased during the past 86 years; On the other hand, several tree and shrub specimens endured for a century, pointing to the slow changes involved as well as the potential for restoration.
Abstract | Full text in HTML | Full text in PDF | Author Info
Wooded meadows are characterised by traditional-historic human use. Deliberate selection of species, pollarding and haymaking has created a complex and biodiverse habitat where small trees and shrubs were prevalent. This study set out to document what happens to such trees and shrubs during succession to forest, the normal fate when wooded meadows are abandoned but also when other open to semi-open patches revert to forest. The study was conducted at a site in southern Sweden where traditional management was abandoned by 1923 when the area was protected for research and allowed to follow natural succession. The current study is a follow-up of a 1937-inventory of small trees and shrubs. The results show a decrease in both population size and canopy cover in the selected species during the past 86 years. Hence, we can expect a loss of these species when wooded meadow are abandoned and left to developed into forests. On the other hand, several tree and shrub specimens endured for a century, pointing to the slow changes involved as well as the potential for restoration.
article id 7798, category Research note
Jānis Liepiņš, Jānis Ivanovs, Andis Lazdiņš, Jurģis Jansons, Kaspars Liepiņš. (2017). Mapping of basic density within European aspen stems in Latvia. Silva Fennica vol. 51 no. 5 article id 7798. https://doi.org/10.14214/sf.7798
Keywords: Populus tremula; wood quality; wood density; bark density; density variations
Highlights: Stem bark is significantly denser than wood and does not follow the same variation patterns along the stem; The main trend in radial variation of wood density was the increase from pith to bark; There is a weak relationship between mean basic density and commonly measured stand and tree parameters.
Abstract | Full text in HTML | Full text in PDF | Author Info

The objective of this study was to investigate basic density and its within-stem variation by studying 84 European aspen stems from 28 forest stands in Latvia. The studied forest stands covered all age classes from young stands to matured forests in representative growth conditions of European aspen. The densities of 2722 wood and 1022 bark specimens were measured from the sampled trees. Only the knot-free wood specimens without obvious wood defects were chosen for analyses. A map of basic density summarizing its radial and axial variations was constructed to show species-specific, within-stem variability and the relationships between density and tree and stand variables were examined. Stem wood and bark of the European aspen show different patterns of basic density variation along the tree stem. Wood density increases from pith to bark up to certain dimensions and shows a slight decrease afterwards. The weighted basic density of bark (446 ± 39.6 kg m–3) was higher than stem wood density (393 ± 30.4 kg m–3). Our results suggest that wood and bark density measurements obtained at breast height can be used for reliable estimation of the densities of whole-tree stem components, while tree parameters such as diameter at breast height (DBH), tree height and social status or stand parameters, including number of trees, basal area and age, are weak predictors in this context.

  • Liepiņš, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: janis.liepins@silava.lv (email)
  • Ivanovs, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: janis.ivanovs@silava.lv
  • Lazdiņš, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: andis.lazdins@silava.lv
  • Jansons, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: jurgis.jansons@silava.lv
  • Liepiņš, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia E-mail: kaspars.liepins@silava.lv
article id 1544, category Research note
Osmo Mattila, Kaisa Hämäläinen, Liina Häyrinen, Sami Berghäll, Katja Lähtinen, Anne Toppinen. (2016). Strategic business networks in the Finnish wood products industry: a case of two small and medium-sized enterprises. Silva Fennica vol. 50 no. 3 article id 1544. https://doi.org/10.14214/sf.1544
Keywords: competitive advantage; wood products; network-based business models
Highlights: Network-based business models are not yet common in the wood products industry; Further research is suggested on network-based co-operation to vitalize industry.
Abstract | Full text in HTML | Full text in PDF | Author Info

The use of network-based business models has been brought up as a means of creating com-petitive edge in the tightening global competition. In practice, adopting network-based models has not yet become common in the wood products industry. The objective of this study is to gain better understanding of types of network-based business models using a case study of two small and medium-sized wood industry companies in Finland (for a sake of anonymity named as A and B). The network of company A is found to consist of mostly of established actors with a new-in-the-market value creation system, whereas network for company B is more stable and has an established value system aiming at growth and incremental innovations. Both networks had experienced difficulties in finding partners and lacked some strategic resources. Via this example we wish to stimulate further research interest on the sources of network-based competitive advantage in the traditional wood product industry in a need of renewal of business models.

  • Mattila, University of Helsinki, Department of Forest Sciences, FI-00014 Helsingin yliopisto, Finland E-mail: osmo.mattila@helsinki.fi
  • Hämäläinen, Siparila Oy, Varaslahdentie 1, FI-40800 Vaajakoski, Finland E-mail: kaisa.hamalainen@siparila.fi
  • Häyrinen, University of Helsinki, Department of Forest Sciences, FI-00014 Helsingin yliopisto, Finland E-mail: liina.hayrinen@helsinki.fi
  • Berghäll, University of Helsinki, Department of Forest Sciences, FI-00014 Helsingin yliopisto, Finland E-mail: sami.berghall@helsinki.fi
  • Lähtinen, University of Helsinki, Department of Forest Sciences, FI-00014 Helsingin yliopisto, Finland E-mail: katja.lahtinen@helsinki.fi
  • Toppinen, University of Helsinki, Department of Forest Sciences, FI-00014 Helsingin yliopisto, Finland E-mail: anne.toppinen@helsinki.fi (email)
article id 1346, category Research note
Āris Jansons, Roberts Matisons, Oskars Krišāns, Baiba Džeriņa, Mārtiņš Zeps. (2015). Effect of initial fertilization on 34-year increment and wood properties of Norway spruce in Latvia. Silva Fennica vol. 50 no. 1 article id 1346. https://doi.org/10.14214/sf.1346
Keywords: Picea abies; wood density; proportion of latewood; tree-rings; high-frequency densitometry; legacy effect
Highlights: The initial fertilization increased the productivity of Picea abies increasing stem volume by 17% at the age of 34 years; The tree-ring width was affected for up to15 years; The fertilization did not affect mean tree-ring density, although the latewood density was increased.
Abstract | Full text in HTML | Full text in PDF | Author Info

Initial fertilisation, when the fertilizer is supplied during the plantation, is applied to improve the competitive ability of the seedlings and hence to increase their growth and productivity; however, fertilization could also alter wood properties and timber quality. In this study, the dimensions and tree-ring parameters – width, proportion of latewood, maximum and mean density, mean earlywood and latewood density – of initially fertilized (by 14, 6 and 11 g of N, P and K per seedling, respectively) Norway spruce (Picea abies Karst.) growing in an experimental plantation in Kalsnava, Latvia (temperate climate region) were assessed. The fertilization significantly increased the dimensions of trees in long-term (ca. 17% increase of stemwood volume). The analysis of tree-ring width suggested that the duration of the effect was ca. 15 years. The maximum and latewood density were higher for the fertilized trees only in a few years. The mean and earlywood density of tree-rings were mainly similar for both treatments. Altogether, considering the one-time application of a limited amount of fertilizer, such treatment had notable and lasting effect on Norway spruce.

  • Jansons, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
  • Matisons, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv (email)
  • Krišāns, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: oskars.krisans@silava.lv
  • Džeriņa, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: baiba.dzerina@silava.lv
  • Zeps, LSRFI “Silava”, Rigas str. 111, Salaspils, Latvia, LV2169 E-mail: martins.zeps@silava.lv
article id 1320, category Research note
Abbot Okotie Oghenekaro, Geoffrey Daniel, Fred O Asiegbu. (2015). The saprotrophic wood-degrading abilities of Rigidoporus microporus. Silva Fennica vol. 49 no. 4 article id 1320. https://doi.org/10.14214/sf.1320
Keywords: simultaneous decay; wood degradation; white rot; delignification
Highlights: Rigidoporus microporus isolates displayed varying saprotrophic capabilities on wood blocks of Rubber tree (Hevea brasiliensis); Percentage mass loss of (Hevea brasiliensis) wood blocks caused by the pathogenic Rigidoporus microporus was significantly higher than that observed with the endophytic isolate; The endophytic isolate has very poor saprotrophic ability on Hevea brasiliensis wood blocks.
Abstract | Full text in HTML | Full text in PDF | Author Info

Saprotrophic wood-decaying abilities of Rigidoporus microporus (Polyporales, Basidiomycota) syn. Rigidoporus lignosus and the structural alterations induced in wood blocks of Hevea brasiliensis Muell. Arg were studied. Mass loss of wood blocks was analyzed after 3 and 6 months respectively and the patterns of decay by pathogenic and endophytic isolates of this fungus were investigated using light microscopy. Effects of temperature on growth of the isolates on malt extract agar were also investigated. The R. microporus isolated from a non-H. brasiliensis host caused the highest percentage mass loss (27.2% after 6 months), followed by isolates ED310 (21.1%) and M13 (15.7%), both collected from diseased H. brasiliensis plantations. The isolate initially identified as an endophyte showed very low saprotrophic wood decay capability (4.3% after 6 months). The optimal temperature for growth of the isolates was 30 °C; except for the endophytic isolate which showed highest growth at 25 °C. Wood samples degraded by the R. microporus isolates showed simultaneous attack of wood cell walls, typical of white rot fungi. Results of the study indicate variability in the wood degrading abilities of the isolates and the potential differences in their physiology are discussed. Our findings further support the need for a taxonomical revision of the Rigidoporus genus.

  • Oghenekaro, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: abbot.oghenekaro@helsinki.fi (email)
  • Daniel, Department of Forest Products/Wood Science, Swedish University of Agricultural Sciences, P.O. Box 7008, SE-75007 Uppsala, Sweden E-mail: geoffrey.daniel@slu.se
  • Asiegbu, Department of Forest Sciences, University of Helsinki, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: fred.asiegbu@helsinki.fi
article id 1305, category Research note
Israel Sánchez-Osorio, Luis Domínguez, Gloria López-Pantoja, Raúl Tapias. (2015). Antennal response of Prinobius myardi to synthetic tree volatiles. Silva Fennica vol. 49 no. 3 article id 1305. https://doi.org/10.14214/sf.1305
Keywords: Quercus; EAG; electroantennography; wood borers; Cerambycidae; plant volatiles; β-pinene
Highlights: Prinobius myardi is a wood borer considered a major threat for Mediterranean oaks, especially Quercus suber and Q. ilex; We performed electroantennographic bioassays to assess olfactory sensitivity of P. myardi to synthetic plant volatiles; P. myardi exhibits a broad sensitivity to common tree volatiles, including those emitted by oaks (α-pinene and β-pinene) or non-host volatiles (1,8-cineole).
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Prinobius myardi Mulsant is a wood borer implicated in the decline of Mediterranean oaks, especially Quercus suber L. and Quercus ilex L. Plant volatiles play an important role in plant-insect interactions, and electroantennography (EAG) is an effective tool for exploring the electrophysiological activity of host plant volatiles on insects. To improve our understanding of the olfactory sensitivity of P. myardi, we recorded EAG responses to 20 tree volatiles, and analyzed the dose-dependent response to five doses (10–4:1 to 1:1 v/v) of the three most EAG-active compounds. Antennae of P. myardi responded to 13 chemicals, mainly monoterpenes and green leaf volatiles, with the strongest EAG responses being observed with β-pinene, (+)-α-pinene and 1,8-cineole. Dose–response profiles showed positive dose-dependent responses for all three compounds. Our results suggest a broad sensitivity of P. myardi to common tree volatiles, particularly some host-related compounds and volatiles associated with wounded trees; the olfactory recognition of ratios of these compounds could play a role in host selection by P. myardi.
  • Sánchez-Osorio, Departamento de Ciencias Agroforestales, ETSI La Rábida, University of Huelva, 21819 Palos de la Frontera (Huelva), Spain ORCID http://orcid.org/0000-0002-6852-7699 E-mail: isanchez@uhu.es (email)
  • Domínguez, Departamento de Ciencias Agroforestales, ETSI La Rábida, University of Huelva, 21819 Palos de la Frontera (Huelva), Spain ORCID http://orcid.org/0000-0002-0131-0057 E-mail: luis.dominguez@dcaf.uhu.es
  • López-Pantoja, Departamento de Ciencias Agroforestales, ETSI La Rábida, University of Huelva, 21819 Palos de la Frontera (Huelva), Spain ORCID http://orcid.org/0000-0002-2659-6127 E-mail: pantoja@uhu.es
  • Tapias, Departamento de Ciencias Agroforestales, ETSI La Rábida, University of Huelva, 21819 Palos de la Frontera (Huelva), Spain E-mail: rtapias@uhu.es
article id 1255, category Research note
Āris Jansons, Roberts Matisons, Līga Puriņa, Una Neimane, Jānis Jansons. (2015). Relationships between climatic variables and tree-ring width of European beech and European larch growing outside of their natural distribution area. Silva Fennica vol. 49 no. 1 article id 1255. https://doi.org/10.14214/sf.1255
Keywords: Fagus sylvatica; introduced species; wood increment; climatic limitation; Latvia; Larix decidua
Highlights: In western Latvia, variation of tree-ring width of European beech and European larch within stands was similar; Dry summers and cold winters caused common event years in tree-rings; Moisture availability at the end of summer was apparently the main limiting factor for tree-ring width; Winter and spring temperature did not have significant and lasting effect on variation of tree-ring width.
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Relationships between climatic variables and tree-ring width (TRW) of dominant European larch (Larix decidua Mill.) and European beech (Fagus sylvatica L.) trees growing outside of their natural distribution area in western Latvia were studied. Chronologies of TRW, which covered the periods 1949–2012 and 1911–2012, were produced for beech and larch, respectively. Common signatures in TRW between both species were observed, but their amplitude differed. Correlation analysis showed that variation of TRW of both species was affected by drought related climatic variables. Tree-ring width of beech was affected by temperature in the previous July and August and the effect of spring and autumn temperature was observed. Since the 1980s, the effect of July precipitation has become significant. Summer precipitation was significant for larch in the mid-part of the previous century; however, temperature in the previous September has become a limiting factor since 1970s. The limiting effect of winter and spring temperature apparently lost its significance around the 1950s.
  • Jansons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: aris.jansons@silava.lv
  • Matisons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: robism@inbox.lv (email)
  • Puriņa, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: liga.purina@silava.lv
  • Neimane, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 E-mail: una.neimane@silava.lv
  • Jansons, Forest Competence Centre, Dzerbenes str. 27, Riga, Latvia, LV1006 E-mail: janis.jansons@mnkc.lv
article id 1026, category Research note
Leif Nutto, Ricardo A. Malinovski, Martin Brunsmeier, Felipe Schumacher Sant’Anna. (2013). Ergonomic aspects and productivity of different pruning tools for a first pruning lift of Eucalyptus grandis Hill ex Maiden. Silva Fennica vol. 47 no. 4 article id 1026. https://doi.org/10.14214/sf.1026
Keywords: forest management; wood quality; work science; handsaw; shear
Highlights: Pruning of hardwoods coming from forest plantations is becoming more and more important in Brazil to replace scarce wood from tropical forests; Evaluating productivity of different pruning tools is essential for the economic output of plantations managed for high quality wood; Pruning activities of forest workers can be classified as “hard” or “very hard work”. Depending on the tools used physical long-term damages may be prevented.
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For the substitution of wood from tropical rainforests pruning of Eucalyptus for producing valuable hardwoods in short rotation plantations has become important. Existing tools and ergonomic aspects of pruning were not yet well analysed under these conditions. The objective of the study is to evaluate the productivity and ergonomics of three different pruning tools in a pruning lift up to 3 m in height. The trees used in the study came from an 18-month-old clonal Eucalyptus grandis stand planted in a 5.0 x 2.8 m spacing. Two manual pruning tools and an electric shear were tested for productivity by using time studies. Ergonomic aspects were evaluated by two test persons using pulse meter equipment. The highest productivity could be shown for the electric shear (236 trees per working day), followed by the manual shear (196 trees/day) and the handsaw (180 trees/day). The heartbeat rate of the two test persons ranged from a level of “very hard work” for the manual tools to “middle hard” and “hard work” for the electric shear. The workload level to achieve the productivity currently reached in practice using purely manual tools is extremely high, exceeding the permanent working capacity of the operators and leading to physical degradation on the long run.
  • Nutto, Department for Forestry, Federal University of Paraná, Av. Pref. Lothário Meissner, 632, Curitiba, PR, Brazil E-mail: lnutto.ufpr@gmail.com (email)
  • Malinovski, Department for Forestry, Laboratory of Forest Operations, Federal University of Paraná, Av. Prefeito Lothario Meissner, 900, Curitiba, PR, Brazil E-mail: ricardo@colheitademadeira.com.br
  • Brunsmeier, Chair of Forest Utilization, University of Freiburg, Werthmannstraße 6, 79085 Freiburg, Germany E-mail: martin.brunsmeier@fobawi.uni-freiburg.de
  • Schumacher Sant’Anna, Department for Forestry, Laboratory of Forest Operations, Federal University of Paraná, Av. Prefeito Lothario Meissner, 900, Curitiba, PR, Brazil E-mail: felipe@colheitademadeira.com.br
article id 60, category Research note
Dominik Röser, Blas Mola-Yudego, Robert Prinz, Beatrice Emer, Lauri Sikanen. (2012). Chipping operations and efficiency in different operational environments. Silva Fennica vol. 46 no. 2 article id 60. https://doi.org/10.14214/sf.60
Keywords: wood-fuel logistics; forest machinery; bioenergy supply
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This research analyses the productivity of energy wood chipping operations at several sites in Austria and Finland. The aim of the work is to examine the differences in productivity and the effects of the operational environment for the chipping of bioenergy at the roadside. Furthermore, the study quantifies the effects of different variables such as forest energy assortments, tree species, sieve size and machines on the overall productivity of chipping. The results revealed that there are significant differences in the chipping productivity in Austria and Finland which are largely based on the use of different sieve sizes. Furthermore, the different operational environments in both countries, as well as the characteristics of the raw material also seem to have an effect on productivity. In order to improve the chipping productivity, particularly in Central European conditions, all relevant stakeholders need to work jointly to find solutions that will allow a greater variation of chip size. Furthermore, in the future more consideration has to be given to the close interlinkage between the chipper, crane and grapple. As a result, investments costs can be optimized and operational costs and stress on the machines reduced.
  • Röser, Finnish Forest Research Institute, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: dominik.roser@metla.fi (email)
  • Mola-Yudego, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland E-mail: bmy@nn.fi
  • Prinz, Finnish Forest Research Institute, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: rp@nn.fi
  • Emer, University of Padova, Department of Land, Agriculture and Forest Systems, Legnaro (PD), Italy E-mail: be@nn.it
  • Sikanen, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland E-mail: ls@nn.fi
article id 91, category Research note
Raisa Mäkipää, Tapio Linkosalo. (2011). A non-destructive field method for measuring wood density of decaying logs. Silva Fennica vol. 45 no. 5 article id 91. https://doi.org/10.14214/sf.91
Keywords: coarse woody debris; carbon stock; decaying wood; wood decomposition; penetrometer; pilodyn
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Decaying dead wood density measurements are a useful indicator for multiple purposes, such as for estimating the amount of carbon in dead wood and making predictions of potential diversity of dead wood inhabiting fungi and insects. Currently, qualitative decay phases are used as wood density estimates in many applications, since measuring the density is laborious. A quantitative measure of density would, however, be preferred over the qualitative one. Penetrometers, which are commonly used for measuring the density of standing trees, might also be applicable to dead wood density measurements. We tested the device for making quick, quantitative measurements of decaying logs. The penetrometer measures the depth into which a pre-loaded spring forces a pin in the wood. We tested pins of 5 and 10 mm diameter together with an original 2.5 mm pin and compared the results with gravimetric density measurements of the sample logs. Our results suggest that the standard pin works for less decayed wood, but for more decomposed wood, the thicker 5 mm pin gave more reliable estimates when the penetration measures were converted to densities with a linear regression function (R2 = 0.62, F = 82.9, p = 0.000). The range of wood densities successfully measured with the 5 mm pin was from 180 to 510 kg m–3. With the 10 mm pin, the measuring resolution of denser wood was compromised, while the improvement at the other end of density scale was not large. As a conclusion, the penetrometer seems to be a promising tool for quick density testing of decaying logs in field, but it needs to be modified to use a thicker measuring pin than the standard 2.5 mm pin.
  • Mäkipää, The Finnish Forest Research Institute, Vantaa, Finland E-mail: raisa.makipaa@metla.fi (email)
  • Linkosalo, The Finnish Forest Research Institute, Vantaa, Finland E-mail: ts@nn.fi
article id 470, category Research note
Paula Jylhä, Juha Laitila. (2007). Energy wood and pulpwood harvesting from young stands using a prototype whole-tree bundler. Silva Fennica vol. 41 no. 4 article id 470. https://doi.org/10.14214/sf.470
Keywords: productivity; energy wood; pulpwood; bundling; integrated harvesting; Fixteri
Abstract | View details | Full text in PDF | Author Info
The productivity of cutting and bundling whole trees using the first prototype of a bundle-harvester comprised of a harwarder as the base machine, an accumulating felling head, and a compacting device was studied in three young stands in order to facilitate the further development of the concept. In addition, the removal and its composition were studied as a means of laying the foundations for developing methods for work rating and measurement on delivery. Bundling enables in-depth integration of pulpwood and energy wood procurement. Both energy wood (crown biomass) and pulpwood can be incorporated into the same bundles, and the subsequent separation of these fractions takes place at the debarking phase at the pulpmill. Bundle-harvesting productivities were relatively low (2.8–3.7 m3/E0-h) when compared to current harvesting technology. Improving working techniques, machine structure, and components showed great potential for increasing the efficiency of the concept. The bundles were dimensionally uniform. Their solid volume varied between 0.350 m3 and 0.513 m3, depending on the bundle assortment and stand properties. Integrating energy wood harvesting with pulpwood harvesting increased removal even by 59 per cent.
  • Jylhä, Finnish Forest Research Institute, Kannus Research Unit, P.O. Box 44, FI-69101 Kannus, Finland E-mail: paula.jylha@metla.fi (email)
  • Laitila, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jl@nn.fi

Category : Discussion article

article id 119, category Discussion article
Markku Larjavaara, Helene C. Muller-Landau. (2011). Cross-section mass: an improved basis for woody debris necromass inventory. Silva Fennica vol. 45 no. 2 article id 119. https://doi.org/10.14214/sf.119
Keywords: biomass; coarse woody debris (CWD); deadwood; log; void space; nominal volume and wood density; carbon in woody detritus
View details | Full text in PDF | Author Info
  • Larjavaara, Smithsonian Tropical Research Institute, Unit 9100 Box 0948, DPO AA 34002-9998, USA, and University of Helsinki, Department of Forest Sciences, Finland E-mail: larjavaaram@si.edu (email)
  • Muller-Landau, Smithsonian Tropical Research Institute, Unit 9100 Box 0948, DPO AA 34002-9998, USA E-mail: hcml@nn.us

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