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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'age'

Category: Article

article id 5639, category Article
Dimitris Athanassiadis. (1997). Residual stand damage following cut-to-length harvesting operations with a farm tractor in two conifer stands. Silva Fennica vol. 31 no. 4 article id 5639. https://doi.org/10.14214/sf.a8541
Keywords: harvesting; logging; thinnings; Sweden; farm-tractors; stand-damage
Abstract | View details | Full text in PDF | Author Info

The objectives of this study were to record residual stand damage during harvesting operations and evaluate the influence of factors such as distance of the tree from the strip road, machine parts, operational phase, on the occurrence of tree wounds. The machine was a farm tractor equipped with a crane mounted on the front axle and a single grip harvester head. The study was carried out in two stands located in Southeast Sweden. Stand 1 was a 30-year-old Norway spruce (Picea abies (L.) H. Karst.) plantation on an afforested pasture while stand 2 was a 90-year-old mixed stand of Norway spruce, Scots pine (Pinus sylvestris L.), birch (Betula pendula Roth) and aspen (Populus tremula L.).

The mean damage percentage was 6.3% for the first stand and 6.5% for the second stand. Sixty-five percent of the wounds were less than 50 cm2, with 91% of the damage occurring on the stem and 91% of the damage on or below the root collar. Sixty-six percent of the wounds produced by the stem under processing or by the harvesting head while only 10% of the wounds were produced by the tractor wheel. Damaged trees were distributed evenly in the crane reach zone. Significant differences were found between rut depths after one, two, four and six passes of the tractor in stand 1.

  • Athanassiadis, E-mail: da@mm.unknown (email)
article id 5637, category Article
Janne Uuttera, Harri Hyppänen. (1997). Relationship between forest management planning units and spatial distribution of forest habitat components in Koli National Park. Silva Fennica vol. 31 no. 4 article id 5637. https://doi.org/10.14214/sf.a8539
Keywords: Finland; forest management planning; forest habitat distribution; Geographic Information Systems; kriging-interpolation; Koli National park
Abstract | View details | Full text in PDF | Author Info

This study examined the relationships between forest management planning units and patches formed by forest habitat components. The test area used was a part of Koli National Park in North Karelia, eastern Finland. Forest management planning units (i.e. forest compartments) were defined by using a traditional method of Finnish forestry which applies aerial photographs and compartment-wise field inventory. Patches of forest habitat components were divided according to subjective rules by using a chosen set of variables depicting the edaphic features and vegetation of a forest habitat. The spatial distribution of the habitat components was estimated with the kriging-interpolation based on systematically located sample plots. The comparisons of the two patch mosaics were made by using the standard tools of GIS. The results of the study show that forest compartment division does not correlate very strongly with the forest habitat pattern. On average, the mean patch size of the forest habitat components is greater and the number of these patches lower compared to forest compartment division. However, if the forest habitat component distribution had been considered, the number of the forest compartments would have at least doubled after intersection.

  • Uuttera, E-mail: ju@mm.unknown (email)
  • Hyppänen, E-mail: hh@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 5618, category Article
Marja-Leena Nykänen, Marianne Broadgate, Seppo Kellomäki, Heli Peltola, Christopher Quine. (1997). Factors affecting snow damage of trees with particular reference to European conditions. Silva Fennica vol. 31 no. 2 article id 5618. https://doi.org/10.14214/sf.a8519
Keywords: stem breakage; stand management; snow accumulation; topography; risk assessment; snow damage; snowfall; risk model
Abstract | View details | Full text in PDF | Author Info

Within the European Community snow damage affects an estimated 4 million m3 of timber every year, causing significant economic losses to forest owners. In Northern Europe, for example, the occurrence of snow damage has increased over the last few decades mainly due to the increase in total growing stock. The most common form of damage is stem breakage, but trees can also be bent or uprooted. Trees suffering snow damage are also more prone to consequential damage through insect or fungal attacks.

Snow accumulation on trees is strongly dependent upon weather and climatological conditions. Temperature influences the moisture content of snow and therefore the degree to which it can accumulate on branches. Wind can cause snow to be shed, but can also lead to large accumulations of wet snow, rime or freezing rain. Wet snow is most likely in late autumn or early spring. Geographic location and topography influence the occurrence of damaging forms of snow, and coastal locations and moderate to high elevations experience large accumulations. Slope plays a less important role and the evidence on the role of aspect is contradictory. The occurrence of damaging events can vary from every winter to once every 10 years or so depending upon regional climatology. In the future, assuming global warming in northern latitudes, the risk of snow damage could increase, because the relative occurrence of snowfall near temperatures of zero could increase.

The severity of snow damage is related to tree characteristics. Stem taper and crown characteristics are the most important factors controlling the stability of trees. Slightly tapering stems, asymmetric crowns, and rigid horizontal branching are all associated with high risk. However, the evidence on species differences is less clear due to the interaction with location. Management of forests can alter risk through choice of regeneration, tending, thinning and rotation. However, quantification and comparison of the absolute effect of these measures is not yet possible. An integrated risk model is required to allow the various locational and silvicultural factors to be assessed. Plans are presented to construct such a model, and gaps in knowledge are highlighted.

  • Nykänen, E-mail: mn@mm.unknown (email)
  • Broadgate, E-mail: mb@mm.unknown
  • Kellomäki, E-mail: sk@mm.unknown
  • Peltola, E-mail: hp@mm.unknown
  • Quine, E-mail: cq@mm.unknown
article id 5616, category Article
Hannu Hökkä, Virpi Alenius, Timo Penttilä. (1997). Individual-tree basal area growth models for Scots pine, pubescent birch and Norway spruce on drained peatlands in Finland. Silva Fennica vol. 31 no. 2 article id 5616. https://doi.org/10.14214/sf.a8517
Keywords: Pinus sylvestris; site quality; Picea abies; Betula pubescens; forest drainage; mixed models; peatlands; growth models
Abstract | View details | Full text in PDF | Author Info

Models for individual-tree basal area growth were constructed for Scots pine (Pinus sylvestris L.), pubescent birch (Betula pubescens Ehrh.) and Norway spruce (Picea abies (L.) Karst.) growing in drained peatland stands. The data consisted of two separate sets of permanent sample plots forming a large sample of drained peatland stands in Finland. The dependent variable in all models was the 5-year basal area growth of a tree. The independent tree-level variables were tree dbh, tree basal area, and the sum of the basal area of trees larger than the target tree. Independent stand-level variables were stand basal area, the diameter of the tree of median basal area, and temperature sum. Categorical variables describing the site quality, as well as the condition and age of drainage, were used. Differences in tree growth were used as criteria in reclassifying the a priori site types into new yield classes by tree species. All models were constructed as mixed linear models with a random stand effect. The models were tested against the modelling data and against independent data sets.

  • Hökkä, E-mail: hh@mm.unknown (email)
  • Alenius, E-mail: va@mm.unknown
  • Penttilä, E-mail: tp@mm.unknown
article id 5615, category Article
Andrew P. Robinson, Timothy G. Gregoire, Harry T. Valentine. (1997). Cut-off importance sampling of bole volume. Silva Fennica vol. 31 no. 2 article id 5615. https://doi.org/10.14214/sf.a8516
Keywords: Monte Carlo methods; forest mensuration; mean-square error; two-stage sampling
Abstract | View details | Full text in PDF | Author Info

Cut-off importance sampling (CIS) is introduced as a means of sampling individual trees for the purpose of estimating bole volume. The novel feature of this variant of importance sampling is the establishment on the bole of a cut-off height, HC, above which sampling is precluded. An estimator of bole volume between predetermined heights HL and HU > HC is proposed, and its design-based bias and mean square error are derived. In an application of CIS as the second stage of a two-stage sample to estimate aggregate bole volume, the gain in precision realized from CIS more than offset its bias when compared to the precision of importance sampling when HC = HU.

  • Robinson, E-mail: ar@mm.unknown (email)
  • Gregoire, E-mail: tg@mm.unknown
  • Valentine, E-mail: hv@mm.unknown
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 5613, category Article
Mikko Peltonen, Kari Heliövaara, Rauno Väisänen. (1997). Forest insects and environmental variation in stand edges. Silva Fennica vol. 31 no. 2 article id 5613. https://doi.org/10.14214/sf.a8514
Keywords: forest management; bark beetles; biodiversity; distribution; edge effect; forest ecology; occurrence
Abstract | View details | Full text in PDF | Author Info

Distribution and occurrence of bark beetles and other forest insects in relation to environmental variation were analysed by multivariate methods. Eight different forest edges were studied using 10 x 10 m sample plots that formed 200 m linear transects perpendicular to the forest edge. Forest edge affected the distribution of insect species only in the edges between mature, non-managed spruce stands and clear cuts or young seedling stands, but not in the pine stands. The occurrence of the selected forest insects mainly depended on variables associated with the amount and quality of suitable woody material. The most significant environmental variables were forest site type, crown canopy coverage, tree species, number of stumps, number of dead spruce trunks and amount of logging waste at site. Quantitative classification of species and sample plots showed that some specialized species (Xylechinus pilosus, Cryphalus saltuarius, Polygraphus poligraphus and P. subopacus) adapted to mature spruce forests, tended to withdraw from the forest edge to interior stand sites. By contrast many generalized species (Pityogenes chalcographus, P. quadridens, Pissodes spp., Hylurgops palliatus, Tomicus piniperda, Dryocoetes spp. and Trypodendron lineatum) benefitted from cuttings and spread over stand borders into mature forest.

  • Peltonen, E-mail: mp@mm.unknown (email)
  • Heliövaara, E-mail: kh@mm.unknown
  • Väisänen, E-mail: rv@mm.unknown
article id 5569, category Article
Esa-Jussi Viitala. (1996). Assessing the effectiveness of non-profit forestry organisations: An ultimate goal approach. Silva Fennica vol. 30 no. 4 article id 5569. https://doi.org/10.14214/sf.a8504
Keywords: forest management; forest policy; Finland; forest owners; evaluation; forestry management associations
Abstract | View details | Full text in PDF | Author Info

This paper is an assessment of what in Finland are referred to as local forest management associations (LFMAs); the local units of a non-profit, forestry-promotion institution. First, the concept of organisational effectiveness is explored and an attempt is made to define it with respect to the LFMAs. The study then seeks to identify the environmental constraints, organisational characteristics and managerial practices differentiating the most effective and least effective associations. Discriminant analysis revealed four determinants of effectiveness: agrarian prosperity in the given area, activeness in marketing services to forest owners, the board of governors' role, and goal setting practices. The results thus indicate that the comparison of managerial policies and practices among LFMAs can provide useful information for improving their effectiveness.

  • Viitala, E-mail: ev@mm.unknown (email)
article id 5568, category Article
Tord Johansson. (1996). Site index curves for European aspen (Populus tremula L.) growing on forest land of different soils in Sweden. Silva Fennica vol. 30 no. 4 article id 5568. https://doi.org/10.14214/sf.a8503
Keywords: Populus tremula; dominant height; European aspen; site index curves; total age; soil type
Abstract | View details | Full text in PDF | Author Info

Growth data were collected from 40 European aspen (Populus tremula L.) stands growing on eight localities in Sweden. The stands ranged in latitude from 56 to 66°N. The mean age of the stands was 32 years (range, 12–63), the mean stand density 1978 stems ha-1 (range, 300–6,000), and the mean diameter at breast height (on bark) 17 cm (range, 8–34).

Site index curves were constructed for total age. Curves for H40 (dominant height at 40 years total age) were made for total Sweden. Curves fitted for H40 total age have another shape than curves presented by other Nordic studies. The curves from the present study have slower growth for young aspens than curves from Norwegian and Finnish conditions. For 50–70-year-old aspen stands, curves from the present study indicate taller heights than from Nordic studies.

Classified soil types from the stands were grouped into three groups: sandy till (17), light clay (15) and medium clay till (4). As there was only one stand growing in the fine sand group and one stand in the heavy clay till group and two stands in the silty till group, these stands were not presented with growth curves. There were no statistically significant differences in site index between the three soil type groups. Some recommendations for management of aspen stand are given. Damages caused by moose, fungi and other injuries are discussed as a problem for height yield production and a good timber quality.

  • Johansson, E-mail: tj@mm.unknown (email)
article id 5603, category Article
Jari Parviainen. (1996). Tasks of forest biodiversity management and monitoring deriving from international agreements. Silva Fennica vol. 30 no. 2–3 article id 5603. https://doi.org/10.14214/sf.a9248
Keywords: forest management; biodiversity; forest protection; sustainable forestry; international agreements; criteria of sustainability; Helsinki process; Montreal process
Abstract | View details | Full text in PDF | Author Info

Four governmental efforts are underway to reach consensus on indicators of sustainable forestry. Through the Helsinki process, European countries have developed and reached a pan-European, binding consensus, The Montreal process includes non-European Temperate and boreal forest countries, the International Tropical Timber Organization (lTTO) have developed guidelines for the sustainable management of natural tropical forests, and the countries around the Amazon basis have developed a joint initiative for creating guidelines of sustainable forest management of the Amazonian tropical rain forests. It is estimated that as many as 15–20 distinct processes are under way in the private sector by non-profit organizations and for-profit companies, some domestic and other international in scope. Perhaps the most wide-ranging definition work of non-governmental organizations is the undertake by the Forest Stewardship Council, FSC. The paper discusses the Helsinki and Montreal processes and the tasks for research.

  • Parviainen, E-mail: jp@mm.unknown (email)
article id 5602, category Article
Anatoly Pisarenko, Valentin Strakhov. (1996). Development and utilization of Russian forest resources. Silva Fennica vol. 30 no. 2–3 article id 5602. https://doi.org/10.14214/sf.a9247
Keywords: forest management; wild berries; forest resources; forest products; natural products; Russian Federation
Abstract | View details | Full text in PDF | Author Info

A presentation based on the historical development of Russia is given in the form of an overview of the development of Russian forest resources, of the wood, non-wood, and biological aspects of the forest ecosystem. The list of non-wood forest resources includes resin, saps, oils, berries, wild nuts, mushrooms, hay harvesting, game animals, etc. The dynamics of the system are presented in the light of the data of the Forest State Account (FSA) of Russia for the period 1956–1993. The most significant changes in the dynamics of Russia's forest resources are related to concentrated, large-scale wood harvesting operations. The dynamics of non-wood resources follow the process of the economic recession in all parts of the forest sector of Russia, the said recession having begun in the mid-1980s. The forests of Russia are considered to be of immense social and cultural value and a globally significant factor contributing to the sustainable development of forest resources.

  • Pisarenko, E-mail: ap@mm.unknown (email)
  • Strakhov, E-mail: vs@mm.unknown
article id 5590, category Article
Heikki Hänninen, Seppo Kellomäki, Ilkka Leinonen, Tapani Repo. (1996). Overwintering and productivity of Scots pine in a changing climate. Silva Fennica vol. 30 no. 2–3 article id 5590. https://doi.org/10.14214/sf.a9235
Keywords: Pinus sylvestris; climate change; ecosystems; frost damage; phenology; forest ecology; gap-type model; model accuracy; model realism; overvintering
Abstract | View details | Full text in PDF | Author Info

The productivity of Scots pine (Pinus sylvestris L.) under changing climatic conditions in the southern part of Finland was studied by scenario analysis with a gap-type forest ecosystem model. Standard simulations with the model predicted an increased rate of growth and hence increased productivity as a result of climatic warming. The gap-type model was refined by introducing an overwintering sub-model describing the annual growth cycle, frost hardiness, and frost damage of the trees. Simulations with the refined gap-type model produced results conflicting with those of the standard simulation, i.e., drastically decreased productivity caused by mortality and growth-reducing damage due to premature dehardening in the changing climate. The overwintering sub-model was tested with frost hardiness data from Scots pine saplings growing at their natural site 1) under natural conditions and 2) under elevated temperature condition, both in open-top chambers. The model predicted the frost hardiness dynamics quite accurately for the natural conditions while underestimating the frost hardiness of the saplings for the elevated temperature conditions. These findings show that 1) the overwintering sub-model requires further development, and 2) the possible reduction of productivity caused by frost damage in a changing climate is less drastic than predicted in the scenario analysis. The results as a whole demonstrated the need to consider the overwintering of trees in scenario analysis carried out with ecosystem model for boreal conditions. More generally, the results revealed a problem that exists in scenario analysis with ecological models: the accuracy of a model in predicting the ecosystem functioning under present climatic condition does not guarantee the realism of the model, nor for this reason the accuracy for predicting the ecosystem functioning under changing climatic conditions. This finding calls for the continuous rigorous experimental testing of ecological models used for assessing the ecological implications of climatic change.

  • Hänninen, E-mail: hh@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
  • Leinonen, E-mail: il@mm.unknown
  • Repo, E-mail: tr@mm.unknown
article id 5575, category Article
Gintautas Mozgeris. (1996). Dynamic stratification for estimating pointwise forest characteristics. Silva Fennica vol. 30 no. 1 article id 5575. https://doi.org/10.14214/sf.a9220
Keywords: stand characteristics; forest mensuration; SMI forest management planning system; dynamic stratification; static stratification
Abstract | View details | Full text in PDF | Author Info

This paper deals with the testing of dynamic stratification for estimating stand level forest characteristics (basal areas, mean diameter, mean height and mean age) for a 117 ha study areas in Finland. The results do not show possibilities to achieve more accurate estimates using only Landsat TM principal components as auxiliary data opposed to static stratification. It was found that in dynamic stratification non-measured observations should be assigned the mean characteristics of the measured observations that belong to the same cube (class) instead of stratification variable classes until a certain limit. If only one principal component is used the number of classes has, however, little influence. Low field values are overestimated and high values underestimated.

The only successful results were obtained using two variables of different origin – the qualitative development stage class and the quantitative 1st principal component. The lowest root mean square error in estimating basal area was 6.40 m2/ha, mean diameter 3.34 cm, mean height 2.65 m and mean age 14.06 years. This increase of stratification accuracy is mainly resulted by the use of development stage class as an auxiliary variable.

  • Mozgeris, E-mail: gm@mm.unknown (email)
article id 5574, category Article
Jouni Vettenranta. (1996). Effect of species composition on economic return in a mixed stand of Norway spruce and Scots pine. Silva Fennica vol. 30 no. 1 article id 5574. https://doi.org/10.14214/sf.a9219
Keywords: Pinus sylvestris; Picea abies; net present value; mixed forests; growth models; tree species composition; forest management practices; felling methods; valuation; soil expectation value; treatment programme
Abstract | View details | Full text in PDF | Author Info

The effect of species mixture was studied in a mixed stand of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) by simulating around 100 different treatment schedules during the rotation in a naturally regenerated even-aged stand located on a site of medium fertility in North Karelia, Finland. Both thinning from below and thinning from above were applied. Optimum rotations were determined by maximising the net present value calculated to infinity and different treatment schedules were compared with the net present value over one rotation as per rotation applied. In the optimum treatment programme, the proportion of pines was decreased by half of the basal area in the first thinning stage and by the end of the rotation to about one third. In thinning from above, the proportion of pines can be maintained at a slightly higher level. It is economically profitable to maintain the growing stock capital at approximately the level recommended by Forest Centre Tapio, a semi-governmental forestry authority. With non-optimum species composition, the loss in net present value over one rotation can be about 10 % in thinning from below and about 20 % in thinning from above.

  • Vettenranta, E-mail: jv@mm.unknown (email)
article id 5563, category Article
Margaret Penner, Hannu Hökkä, Timo Penttilä. (1995). A method for using random parameters in analyzing permanent sample plots. Silva Fennica vol. 29 no. 4 article id 5563. https://doi.org/10.14214/sf.a9214
Keywords: Pinus sylvestris; drained peatlands; drainage; competition; sampling; random parameters
Abstract | View details | Full text in PDF | Author Info

The use of random parameter models in forestry has been proposed as one method of incorporating different levels of information into prediction equations. By explicitly considering the variance-covariance structure of observations and considering some model parameters as random rather than fixed, one can incorporate more complex error structures in analysing data.

Competition indices and variance component techniques were applied to 92 Scots pine (Pinus sylvestris L.) -dominated permanent sample plots on drained peatlands in Northern Finland. By quantifying stand, plot, and tree level variation, it was possible to identify the level (stand, plot or tree) at which the explanatory variables contributed to the model. The replication of plots within stands revealed little variation among plots within a single stand but significant variation occurred at stand and tree levels. Positive and negative effects of inter-tree competition are identified by examining simple correlation statistics and the random parameter model.

  • Penner, E-mail: mp@mm.unknown (email)
  • Hökkä, E-mail: hh@mm.unknown
  • Penttilä, E-mail: tp@mm.unknown
article id 5555, category Article
Mauno Pesonen, Arto Kettunen, Petri Räsänen. (1995). Modelling non-industrial private forest landowners’ strategic decision making by using logistic regression and neural networks: Case of predicting the choice of forest taxation basis. Silva Fennica vol. 29 no. 2 article id 5555. https://doi.org/10.14214/sf.a9206
Keywords: logistic regression; Finland; Neural Networks; forest owners; forest taxation; non-industrial private forest landowners,; timber management strategies
Abstract | View details | Full text in PDF | Author Info

In this study, logistic regression and neural networks were used to predict non-industrial private forests (NIPF) landowners’ choice of forest taxation basis. The main frame of reference of the study was the Finnish capital taxation reform of 1993. As a consequence of the reform, landowners were required to choose whether to be taxed according to site-productivity or realized-income during the coming transition period of thirteen years.

The most important factor affecting the landowners’ choice of taxation basis was the harvest rate during the transition period, i.e. the chosen timber management strategy. Furthermore, the estimated personal marginal tax rate and the intention to cut timber during next three years affected the choice. The descriptive landowner variables did not have any marked effect on the choice of forest taxation basis.

On average, logistic regression predicted 71% of the choices correctly; the corresponding figure for neural networks was 63%. In both methods, the choice of site-productivity taxation was predicted more accurately than the choice of realized-income taxation. An increase in the number of model variable did not significantly improve the results of neural networks and logistic regression.

  • Pesonen, E-mail: mp@mm.unknown (email)
  • Kettunen, E-mail: ak@mm.unknown
  • Räsänen, E-mail: pr@mm.unknown
article id 5536, category Article
Roar Skuterud, Jon Dietrichson. (1994). Budburst in detached birch shoots (Betula pendula) of different varieties winter-stored in darkness at three different temperatures. Silva Fennica vol. 28 no. 4 article id 5536. https://doi.org/10.14214/sf.a9176
Keywords: Betula pendula; climatic change; budburst; buds; frost; developmental stages; heat sums; threshold temperatures
Abstract | View details | Full text in PDF | Author Info

Budburst timing and the relationship to storage temperature and duration were investigated in four varieties (entries) of 1–2 metres tall silver birch (Betula pendula Roth) trees. A total of 2,160 shoots were sampled, and the material stores in darkness at 0, 3 or 6 °C from November 29, 1993. When the shoots were placed in storage, they had been through a period of 29 days with temperatures below 0°C (since October 15). By that time the autumn dormancy was assumed already broken, and the trees were expected to respond to increased temperature by bud development. On January 4, 1994, and on four subsequent dates, January 19, February 1, March 4 and March 17, shoots were taken out of storage and set in growth chambers at 9, 12 or 15°C. The time to budburst was recorded.

Duration of storage, storage temperatures and varieties were all highly significant for budburst. The interaction terms were of less statistical importance. Based on the contrast between the three different growth chamber environments, three different methods were used to calculate the threshold temperatures for each entry. In spite of the pre-selection of variable budburst performers, the threshold values, varying between 0°C to -2°C, could not be shown to be statistically different. According to the results, the time of budburst changes in accordance with both winter and spring temperatures, being extremely early after a mild winter and warm spring, given sufficient autumn chilling. The similarities in the threshold temperatures indicate that the ranking in earliness between varieties will most likely be the same from year to year without regard to climate change.

  • Skuterud, E-mail: rs@mm.unknown (email)
  • Dietrichson, E-mail: jd@mm.unknown
article id 5535, category Article
Mats Hannerz. (1994). Predicting the risk of frost occurrence after budburst of Norway spruce in Sweden. Silva Fennica vol. 28 no. 4 article id 5535. https://doi.org/10.14214/sf.a9175
Keywords: Norway spruce; Picea abies; Sweden; provenances; budburst; frost; developmental stages; heat sums
Abstract | View details | Full text in PDF | Author Info

Temperature sums required for budburst in various Norway spruce (Picea abies (L.) H. Karst.) provenances were determined, and weather statistics were then used to predict the risk of potentially damaging frosts at 11 locations in Sweden. Frost risk was quantified as the probability of a frost occurring within 100 day-degrees (two weeks) after budburst. The examples provided show that a spruce seedling from central Sweden has to sustain almost twice as many frost occassions as a seedling from Belorussia, when planted in southern and central Sweden. The method presented here can be used for mapping early summer frost risk in Sweden and for supporting provenance transfer guidelines.

  • Hannerz, E-mail: mh@mm.unknown (email)
article id 5533, category Article
Reijo Solantie. (1994). Effect of weather and climatological background on snow damage of forests in Southern Finland in November 1991. Silva Fennica vol. 28 no. 3 article id 5533. https://doi.org/10.14214/sf.a9173
Keywords: snow damages; climate; precipitation; temperature; snow damage; snow cover; storms
Abstract | View details | Full text in PDF | Author Info

Snow damage to forests in Southern Finland in November 1991 was examined in relation to meteorological conditions. The combined effect of different factors proved to be necessary for severe damage. First, the snow load, in terms of precipitation, should exceed a certain limit. The limit can be set for weak or moderate damage at about 40 mm and for very severe damage at about 60 mm. Second, temperature at the time of precipitation should be above 0°C, which enables the slightly wet snow to attach to twigs during the subsequent period with temperature below 0°C. On the other hand, temperatures exceeding 0.6°C prohibit damage by permitting the snow load to fall from the branches. Wind speed exceeding 9 ms-1, as observed 15 m above ground, were strong enough to dislodge the snow which is not attached, and thus reduce the damage. There are few statistics either of snow damage or of the relation between the snow damage and precipitation. However, there is causal connection between snow damage and heavy snowfalls. Therefore, the regions with a high frequency of heavy snowfalls, as indicated by orographical features and occurrence of thick snow cover, were investigated.

  • Solantie, E-mail: rs@mm.unknown (email)
article id 5401, category Article
Akmal S. Hyder, Lars Lönnstedt, Markku Penttinen. (1994). Outline of accounting for non-industrial private woodlots. Silva Fennica vol. 28 no. 2 article id 5401. https://doi.org/10.14214/sf.a9167
Keywords: non-industrial private forestry; financial accounting; net profit of the enterprise; calculated profit of the property; cost accounting; forest management strategies
Abstract | View details | Full text in PDF | Author Info

For non-industrial private forest (NIPF) owners land with its timber production is an example of a capital asset. Developments in the asset’s value and yield depend not only on forest management but also on other factors that the owner cannot control, for example timber prices and the production circumstances, such as soil and climate. One important basis for decision making related to management strategy and, in the short run, to cutting and silvicultural activities is economic analysis and accounting. The owner has to decide whether to invest more in his property (planting, cleaning, building of forest roads) or disinvest (sell timber or the holding). He has to find ways to increase revenue and cut costs.

However, generally accepted accounting practices for NIPF owners are lacking. Applying business economic accounting principles and forestry accounting traditions, we outline a proposal for a profit and loss accounting and balance sheet for NIPF holdings with a view towards increasing economic awareness among private owners. Key concepts are net profit of the enterprise and calculated profit of the property. Other profit measurements that are used are gross margin, forestry margin, operating margin and operating profit. Calculated profit is based on adjusted net profit. The main concern, however, is to consider the change in the holding’s market value caused by changes in stock volume, quality and price. The contents of the accounting framework development here are applied to three management strategies. The return on investment (ROI) of forestry is compared with other investment alternatives.

  • Hyder, E-mail: ah@mm.unknown (email)
  • Lönnstedt, E-mail: ll@mm.unknown
  • Penttinen, E-mail: mp@mm.unknown
article id 5397, category Article
Juha Kaitera, Risto Jalkanen. (1984). Old and fresh Gremmeniella abietina damage on Scots pine in eastern Lapland in 1992. Silva Fennica vol. 28 no. 2 article id 5397. https://doi.org/10.14214/sf.a9166
Keywords: Pinus sylvestris; Gremmeniella abietina; shoots; fungal damage; assessment; plant diseases
Abstract | View details | Full text in PDF | Author Info

Damage on Scots pine (Pinus sylvestris L.) caused by Gremmeniella abietina (Lagerb.) Morelet was assessed in the summer of 1992 in 67 stands in eastern Lapland. The area and severity of damage were smaller and lighter than had earlier been estimated and occurred especially in stands in the first-thinning stage or in middle-age. Significant new infection of 1991 occurred in stands previously heavily infected by G. abietina near Kemihaara river, lake Naruska, the Naruska river, the Tuntsa river and lake Vilma. Fresh damage occurred mainly in the lower or middle parts of the Scots pine canopies.

  • Kaitera, E-mail: jk@mm.unknown (email)
  • Jalkanen, E-mail: rj@mm.unknown
article id 5527, category Article
Leena Finér. (1994). Variation in needle nutrient concentrations in the crown of Scots pine on peatland. Silva Fennica vol. 28 no. 1 article id 5527. https://doi.org/10.14214/sf.a9161
Keywords: Scots pine; crown; conifer needles; leaf age; plant analysis; nutrient content
Abstract | View details | Full text in PDF | Author Info

Variation in needle nutrient concentrations with age and vertical location in the crown was studied in three Scots pine (Pinus sylvestris L.) stands growing on peat soils in Eastern Finland. The concentrations of N, P, Fe and Zn decreased down the crown and those of Ca and Mn increased. Potassium and magnesium concentration patterns differed between sites.

Potassium and Mg concentrations were highest in the current needles at all heights in the crown, iron and manganese concentrations were highest in the oldest needles. The concentrations of N, P and Zn did not vary with needle age.

  • Finér, E-mail: lf@mm.unknown (email)
article id 5523, category Article
Reijo Solantie. (1993). Snow and soil frost in Finnish forests. Silva Fennica vol. 27 no. 4 article id 5523. https://doi.org/10.14214/sf.a15684
Keywords: snow damages; Finland; ground vegetation; forest ecology; flora; snow cover; fauna
Abstract | View details | Full text in PDF | Author Info

Abundant snowfalls and thick snow cover influence forest ecology mainly in two ways. Snow loading increases the number of damaged stems, which increases the amount of decay in stems, in its turn important for many animals. Second, the ground remains unfrozen under the snow cover, which is of crucial importance for many perennial species of ground vegetation. These winter phenomena also have influenced the early Finnish culture as man in his everyday life in the wilderness was in close contact with nature. In this paper, ecological interactions between snow conditions, forest flora, fauna and early culture are discussed mainly with reference to the province of Uusimaa in Southern Finland.

  • Solantie, E-mail: rs@mm.unknown (email)
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 5519, category Article
Jyrki Kangas, Jari Karsikko, Laura Laasonen, Timo Pukkala. (1993). A method for estimating the suitability function of wildlife habitat for forest planning on the basis of expertise. Silva Fennica vol. 27 no. 4 article id 5519. https://doi.org/10.14214/sf.a15680
Keywords: forest management; models; wildlife management; black grouse; production functions; multiple use; Lururus tetrix
Abstract | View details | Full text in PDF | Author Info

In the method presented in this study, a group of experts evaluate, in a pairwise manner, a set of forest areas with respect to the game species considered. On the basis of these comparisons, relative priorities of forest areas are estimated using the eigenvalue technique. Using regression analysis, a habitat suitability function is estimated in which the priority is predicted by measures already familiar in forest planning. As a case study, a habitat suitability function was estimated for black grouse (Tetrao tetrix, Lururus tetrix L.). The function is applicable in forestry planning carried out using modern planning techniques.

The PDF includes an abstract in Finnish.

  • Kangas, E-mail: jk@mm.unknown (email)
  • Karsikko, E-mail: jk@mm.unknown
  • Laasonen, E-mail: ll@mm.unknown
  • Pukkala, E-mail: tp@mm.unknown
article id 5518, category Article
Heikki Hänninen, Seppo Kellomäki, Kaisa Laitinen, Brita Pajari, Tapani Repo. (1993). Effect of increased winter temperature on the onset of height growth of Scots pine: a field test of a phenological model. Silva Fennica vol. 27 no. 4 article id 5518. https://doi.org/10.14214/sf.a15679
Keywords: Pinus sylvestris; height growth; frost damage; bud burst; climatic change
Abstract | View details | Full text in PDF | Author Info

According to a recently presented hypothesis, the predicted climatic warming will cause height growth onset of trees during mild spells in winter and heavy frost damage during subsequent periods of frost in northern conditions. The hypothesis was based on computer simulations involving a model employing air temperature as the only environmental factor influencing height growth onset. In the present study, the model was tested in the case of eastern Finnish Scots pine (Pinus sylvestris L.) saplings. Four experimental saplings growing on their natural site were surrounded by transparent chambers in autumn 1990. The air temperature in the chambers was raised during the winter to present an extremely warm winter under the predicted conditions of a double level of atmospheric carbon dioxide. The temperature treatment hastened height growth onset by two months as compared to the control saplings, but not as much as expected on the basis of the previous simulation study. This finding suggests that 1) the model used in the simulation study needs to be developed further, either by modifying the modelled effect of air temperature or by introducing other environmental factors, and 2) the predicted climatic warming will not increase the risk of frost damage in trees as much as suggested by the previous simulation study.

The PDF includes an abstract in Finnish.

  • Hänninen, E-mail: hh@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
  • Laitinen, E-mail: kl@mm.unknown
  • Pajari, E-mail: bp@mm.unknown
  • Repo, E-mail: tr@mm.unknown
article id 5517, category Article
Tuomo Kotimäki. (1993). Ristipaineet valtion metsien käytön valintatilanteissa. Silva Fennica vol. 27 no. 3 article id 5517. https://doi.org/10.14214/sf.a15678
English title: Contradictory targets in the use of state forests of Finland.
Original keywords: valtionmetsät; Metsähallitus; metsänhoito; metsien monikäyttö; aluepolitiikka; maankäyttö; kestävä metsätalous
English keywords: forest management; Finland; forest management planning; Forest Service; state forests; multiple use of forests; conflicting targets; land use; regional planning
Abstract | View details | Full text in PDF | Author Info

The paper discusses the principles of forest management in the state forests of Finland, and the contradictions in choosing between the different land uses. These principles of the forest management are sustainable use of natural resources, economic and effective management, and taking in account nature conservation, protection of environment, recreation services and employment issues in all activities of the Forest Service. Even regional policy affects the management planning in the state forests.

  • Kotimäki, E-mail: tk@mm.unknown (email)
article id 5516, category Article
Veli-Pekka Järveläinen. (1993). Yksityismetsätalous ja arvojen muutos. Silva Fennica vol. 27 no. 3 article id 5516. https://doi.org/10.14214/sf.a15677
English title: Private forestry and the changing values.
Original keywords: metsänhoito; yksityismetsätalous; metsänomistajat; arvot
English keywords: forest management; forestry; values; Finland; forest owners; private forests
Abstract | View details | Full text in PDF | Author Info

Forests have been economically important for Finnish private forest owners at all times, but the use of forests has changed markedly since 1920s, when forests were mainly used for collecting household timber, and the cuttings were often exploitative because of the farmer’s need for money. The present situation is totally different. Need for household timber is marginally small, and private forestry produces mainly timber for sale. The sales of timber have increased, but due to better forest management the growing stock in the private forests has increased. The article discusses how the changes in values of forest owners has and will affect the stage of private forestry.

  • Järveläinen, E-mail: vj@mm.unknown (email)
article id 5515, category Article
Seppo Vehkamäki. (1993). Metsien käytön muutospaineet. Silva Fennica vol. 27 no. 3 article id 5515. https://doi.org/10.14214/sf.a15676
English title: Pressures for changes in the use of forests.
Original keywords: metsänhoito; metsätalous; metsien monikäyttö; kestävyys; tuottavuus; tehokkuus
English keywords: forest management; productivity; sustainability; forestry; multiple use of forests; effectiveness
Abstract | View details | Full text in PDF | Author Info

The paper discusses how the general trend towards increasing growth and productivity in the European societies is expressed also in forestry. It is reflected, for instance, in the increasing production and productivity of forest industries. Technological progress and call for economic growth require great flexibility from all resources. These pressures for effectiveness and production also concern Finnish forestry and forest management. Industrialization, urbanization and development of forestry have increased the pressure to use forests in recreation, preserving human environment and nature conservation in addition to production of timber. Through the development the definition of sustainability has become wider.

  • Vehkamäki, E-mail: sv@mm.unknown (email)
article id 5509, category Article
Markku Siitonen. (1993). Experiences in the use of forest management planning models. Silva Fennica vol. 27 no. 2 article id 5509. https://doi.org/10.14214/sf.a15670
Keywords: forest policy; forest inventories; stand management; linear programming; forest resources
Abstract | View details | Full text in PDF | Author Info

Model-based information systems have proved valuable planning tools for analysing the production possibilities of forests as well as for understanding forest resources dynamics, stand management practices and forest economics. Computerized forest models implemented in the users’ information systems facilitate the transfer and application of research results in practical forestry.

Conclusions and visions concerning modelling are drawn from experiences in developing the MELA system and its application in solving timber production problems on both the national and forest holding level in Finland. The precondition for predicting forest resource dynamics and for planning the utilization of forests is to accept conditions, uncertainties and a restricted period of time.

The interactive process of forest resource, growth and drain monitoring, and forest management planning supported by forest research and modelling, are the means to enable an operational information base for a dynamic regulation and adaptation strategy for forest resource management under changing conditions and uncertainty.

The PDF includes an abstract in Finnish.

  • Siitonen, E-mail: ms@mm.unknown (email)
article id 5507, category Article
John L. Innes. (1993). Methods to estimate forest health. Silva Fennica vol. 27 no. 2 article id 5507. https://doi.org/10.14214/sf.a15668
Keywords: damage; monitoring; crown condition; air pollution; bioindicators; forest healt; indicator organisms
Abstract | View details | Full text in PDF | Author Info

A range of different indices are available for assessing the health of trees in forests. An even larger range can be used for the assessment of the health of forest ecosystems. Most studies made in connection with ”forest decline” and the impact of air pollution and other environmental stresses on forests have concentrated on the assessment of crown transparency and crown discoloration in individual trees. These are non-specific indicators which are now known to be sometimes of relatively little value when determining the health of a forest ecosystem. Numerous problems exist with both, and the standardisation of assessments between and even within countries has not been achieved. Consequently, studies claiming to compare ”defoliation” between different countries cannot be substantiated. The emphasis on crown transparency and crown discoloration has resulted in the neglect of a number of other indices that could be of considerable value. These include a variety of visual measures of crown condition and also several non-visual bioindicators. Some of these techniques are objective, reducing the present reliance on observed standardization. A large number of potential techniques are currently at the research stage and have yet to be adequately tested in field trials. This represent an area where a substantial amount of further research is required.

  • Innes, E-mail: ji@mm.unknown (email)
article id 5504, category Article
Heli Peltola, Seppo Kellomäki. (1993). A mechanistic model for calculating windthrow and stem breakage of Scots pines at stand age. Silva Fennica vol. 27 no. 2 article id 5504. https://doi.org/10.14214/sf.a15665
Keywords: Pinus sylvestris; wind; stems; breakage; windspeed; breaking stress; bending models
Abstract | View details | Full text in PDF | Author Info

A model for the mechanism of windfall and stem breakage was constructed for single Scots pine (Pinus sylvestris L.) at the stand edge. The total turning moment arising from the wind drag and from the bending of stem and crown was calculated along with the breaking stress of the stem. Similarly, the support given by the root -soil plate anchorage was calculated. Windspeed variation within the crown and the vertical distribution of stem and crown weight were taken into account. Model computations showed that trees having a large height to diameter ratio were subjected to greater risk of falling down or breaking than trees with a small height to diameter ratio. The windspeed required to blow down a tree or break the stem of a tree decreased if the height to diameter ratio or the crown to stem ratio of trees increased.
The PDF includes an abstract in Finnish.

  • Peltola, E-mail: hp@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
article id 5493, category Article
Juha Heiskanen. (1993). Water potential and hydraulic conductivity of peat growth media in containers during drying. Silva Fennica vol. 27 no. 1 article id 5493. https://doi.org/10.14214/sf.a15654
Keywords: shrinkage; matric potential; perlite; substrates; water availability; containers
Abstract | View details | Full text in PDF | Author Info

The matric potential and unsaturated hydraulic conductivity of peat-based growth media in containers was measured continuously as a function of drying. The particle size distribution and the water retention characteristics of the media were determined from parallel samples. The growth media used were a light, coarse graded Sphagnum peat, a medium graded Sphagnum peat and a mixture of a perlite and the medium graded Sphagnum peat. Containers of two types were packed with the media and allowed to evaporate from saturation. Matric potential was measured automatically using tensiometers during drying.

In both container types, the matric potential of the media was similar down to 10 kPa at each of the three levels measured during drying. Further drying resulted in a large matric potential gradient between the upper and the middle levels. During drying, there was also clear shrinkage of the media. When the matric potential at the upper level reached ca. -80 kPa, the decrease in height of the media was 5–23 %. The estimated hydraulic conductivity of the media during drying was rather similar. The hydraulic conductivity of the peat-perlite mixture was, however, slightly lower than that of the pure peat media. The hydraulic conductivity decreased linearly on a log-log-scale from ca. 10-5 to less than 10-10 m/s as the matric potential decreased from -3 to -60 kPa. The hydraulic conductivity of the media was comparable to coarse sand at matric potentials below -10 kPa. The decrease in hydraulic conductivity during drying and the possible weakening of soil-root contact due to shrinkage may considerably affect the availability of water to plants.
The PDF includes an abstract in Finnish.

  • Heiskanen, E-mail: jh@mm.unknown (email)
article id 5492, category Article
Ismo Nousiainen, Timo Pukkala. (1992). Use of computer graphics for predicting the amenity of forest trails. Silva Fennica vol. 26 no. 4 article id 5492. https://doi.org/10.14214/sf.a15653
Keywords: forest management; forest planning; simulation; landscape; recreation; amenity value of forests
Abstract | View details | Full text in PDF | Author Info

Ten trails, one kilometre each, were evaluated by 15 persons for scenic beauty, recreational value and variety. All trails passed through commercially managed forests dominated by conifers. The trails were first evaluated by viewing computer simulations based on a series of graphical illustrations of forest landscapes, then from a slide show, and finally in the field. In the computer simulation and slide show, landscape pictures along the trail at an interval of 35–40 m were presented for 3–4 seconds. The ranks between slide show and field were slightly more similar than those between simulation and field. The mean correlation of 12 persons between the field ranking and assessment of either computer simulations or slide shows or graphics than scenic beauty or recreational value. Spearman’s rank correlations computed from median scores of a group of 12 peers were clearly better than the average of individual persons varying from 0.6 to 0.9.

The PDF includes an abstract in Finnish

  • Nousiainen, E-mail: in@mm.unknown (email)
  • Pukkala, E-mail: tp@mm.unknown
article id 5489, category Article
Markku Penttinen, Matti Kinnunen. (1992). Profitability of forestry in jointly-owned forests of Northeastern Finland and Lapland. Silva Fennica vol. 26 no. 4 article id 5489. https://doi.org/10.14214/sf.a15650
Keywords: forest management; forestry; northern Finland; profitability; co-ownership; jointly owned forest holdings
Abstract | View details | Full text in PDF | Author Info

The profitability of jointly owned forest holdings in the two northernmost forest board districts of Finland was studied by means of ratio analysis. A time series of profit and loss statements and balance sheets from 33 holdings covering the fiscal years ending 1981–1990 served as the database. The studied area was 348,038 ha, the allowable cut 304,300 m3 per year and the average turnover, deflated by the wholesale price index, FIM 57.6 million per year. The key result obtained was that the average annual profit was FIM 107 per hectare and FIM 110 per m3. The time series showed that the ratios had increased significantly over the calculation period.

The PDF includes an abstract in Finnish.

  • Penttinen, E-mail: mp@mm.unknown (email)
  • Kinnunen, E-mail: mk@mm.unknown
article id 5486, category Article
Kari Löyttyniemi, Risto Heikkilä, Seppo Repo. (1992). Pine tar in preventing moose browsing. Silva Fennica vol. 26 no. 3 article id 5486. https://doi.org/10.14214/sf.a15647
Keywords: Pinus sylvestris; Scots pine; Alces alces; repellent; moose; browsing damage; control
Abstract | View details | Full text in PDF | Author Info

The efficacy of pine tar as a moose (Alces alces L.) contact repellent was tested in young Scots pine (Pinus sylvestris L.) stands suffering from moose damage in Southern Finland during the winter 1981–82. Application of tar to shoots by spraying protected the trees satisfactorily throughout the winter.

The PDF includes an abstract in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
  • Heikkilä, E-mail: rh@mm.unknown
  • Repo, E-mail: sr@mm.unknown
article id 5484, category Article
Jyrki Kangas, Timo Pukkala. (1992). A decision theoretic approach applied to goal programming of forest management. Silva Fennica vol. 26 no. 3 article id 5484. https://doi.org/10.14214/sf.a15645
Keywords: forest management; models; forest planning; decision analysis; goal programming; optimization methods
Abstract | View details | Full text in PDF | Author Info

An alternative approach to formulating a forestry goal programming problem is presented. First, single objective optima levels are solved. The Analytical Hierarchy Process is applied in the estimation of a priori weights of deviations from the goal target levels. The ratios of the weights can be interpreted as relative importance of the goals, respectively. The sum of the weighted deviations from all single optima levels associated with the management goals is minimized. Instead of absolute deviations, relative ones are used. A case study problem of forest management planning with several objectives, measured in different units, is analysed.

The PDF includes an abstract in Finnish.

  • Kangas, E-mail: jk@mm.unknown (email)
  • Pukkala, E-mail: tp@mm.unknown
article id 5479, category Article
Douglas K. Loh, Hannu Saarenmaa. (1992). Design of integrated forest resource information systems. Silva Fennica vol. 26 no. 2 article id 5479. https://doi.org/10.14214/sf.a15640
Keywords: forest management; databases; information systems; X Window System
Abstract | View details | Full text in PDF | Author Info

Managing forests and other natural resources requires merging of data and knowledge from many fields. Research efforts in many countries have simultaneously aimed at computer applications to help managing the large amounts of data involved and the complexities of decision making. This has invariably led to large integrated systems. An integrated system is software that consists of modules for various tasks in natural resource management, spatial analysis, simulation and optimization, diagnostic reasoning, levels, and communicating with the user.

The paper presents an overview of the need, levels and historical development of integrated systems. Newly emerged technologies, especially object-oriented programming and the X Window System with its associated environment have given new flexibility and transparency to the designs. The client-server architecture is found out as an ideal model for integrated systems. The paper describes an implementation of these ideas, the INFORMS system that supports the information needs of district level forest management planning.

The PDF includes an abstract in Finnish.

  • Loh, E-mail: dl@mm.unknown (email)
  • Saarenmaa, E-mail: hs@mm.unknown
article id 5478, category Article
Seppo Kellomäki, Marja Kolström. (1992). Computations on the management of seedling stands of Scots pine under the influence of changing climate in southern Finland. Silva Fennica vol. 26 no. 2 article id 5478. https://doi.org/10.14214/sf.a15639
Keywords: Pinus sylvestris; forest management; models; Betula pendula; Scots pine; silver birch; simulation; climatic change; seedling stands
Abstract | View details | Full text in PDF | Author Info

Model computations on the management of Scots pine (Pinus sylvestris L.) at the seedling stage showed that a rising temperature due to the suggested climate change could increase the competition capacity of birch species (Betula pendula) more than Scots pine, whose growth could even decline during the course of a rise in temperature. A temperature rise could, thus, bring the time of removal of birches forward when aiming at Scots pine timber stands composed of these tree species. The increasing proportion of birches makes the removal of birches even more urgent and emphasizes the need for careful management of Scots pine stands under rising temperatures. The first thinning of Scots pine is generally brought forward; this is particularly the case when wide spacing is applied in planting. A furthrer rise in temperature magnifies the above patterns by reducing further the competitive capacity of Scots pine in relation to birches.
The PDF includes an abstract in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Kolström, E-mail: mk@mm.unknown
article id 5469, category Article
Risto Heikkilä, Kari Löyttyniemi. (1992). Growth response of young Scots pines to artificial shoot breaking simulating moose damage. Silva Fennica vol. 26 no. 1 article id 5469. https://doi.org/10.14214/sf.a15627
Keywords: Pinus sylvestris; height growth; timber quality; Alces alces; stems; diameter growth; breakage; moose damage
Abstract | View details | Full text in PDF | Author Info

The main stem of young Scots pine (Pinus sylvestris L.) trees was cut off halfway along the current leading shoot and the two previous years’ leading shoots to simulate moose (Alces alces) damage. Trees of the same size were chosen as controls before treatments. The experiment was inspected ten years after artificial stem breakage. Removing the current leading shoot and the second shoot did not essentially affect the height and diameter growth of the trees. Removal down to the third shoot reduced the height as well as diameter growth. The average loss in growth was equivalent to less than one year’s growth. When the stem was cut off at the second or third shoot, stem crookedness and the presence of knots resulted in stem defects that will subsequently reduce the sawtimber quality. A high proportion of the stem defects will obviously still be visible at the first thinning cutting. Removing injured trees as pulpwood and pruning the remaining parts of cut stems evidently improves the quality of pine stand with moose damage.

The PDF includes an abstract in Finnish.

  • Heikkilä, E-mail: rh@mm.unknown (email)
  • Löyttyniemi, E-mail: kl@mm.unknown
article id 5451, category Article
Maija Salemaa, Eeva-Liisa Jukola-Sulonen, Martti Lindgren. (1991). Forest condition in Finland, 1986-1990. Silva Fennica vol. 25 no. 3 article id 5451. https://doi.org/10.14214/sf.a15605
Keywords: needle age; Finland; defoliation; discolouration; cones; needle cast; air pollution; leaves
Abstract | View details | Full text in PDF | Author Info

The results of the Finnish forest condition survey carried out during 1986–90 in background areas are presented. The same 3,388 forest trees (1,897 Scots pines (Pinus sylvestris L.), 1,289 Norway spruces (Picea abies (L.) H. Karst. And 202 broadleaves) on 450 mineral soil sample plots were examined annually. Growth characteristics (defoliation, the number of needle age classes, branch damage and needle discolouration), fertility and abiotic and biotic damage express the general vitality of the trees and are not specific for air pollutants. A correlative approach was applied in analysing the factors which may explain the regional pattern and changes in defoliation.

Average tree-specific degree of defoliation was 9% in pine, 21% in spruce and 12% in broadleaves in 1990. Altogether 11% of the pines, 42% of the spruces and 16% of the broadleaves have lost over 20% of their needles or leaves. Defoliation in spruce was the same as in the previous year, but in pine and broadleaves it had slightly decreased. Defoliation had increased by 5 %-units in pine, 16 %-units in spruce and 7 %-units in broadleaves during the whole study period 1986–90.

High stand age and different weather and climatic factors greatly affected forest defoliation in background areas in Finland. Pine cancer (Ascocalyx abietina) has enhanced defoliation in pine in the western part of the country. Air pollutants have evidently contributed to the increase of defoliation in the most polluted parts of Southern Finland. In pine a significant positive correlation was found between modelled sulphur deposition and the average stand-specific degree of defoliation as well as with the increase in average 5-year defoliation in Southern Finland. It is suspected that green algae growing on needles of spruce in Southern Finland indicates elevated nitrogen deposition levels.

The PDF includes an abstract in Finnish.

  • Salemaa, E-mail: ms@mm.unknown (email)
  • Jukola-Sulonen, E-mail: ej@mm.unknown
  • Lindgren, E-mail: ml@mm.unknown
article id 5450, category Article
Bo Långström, Claes Hellqvist. (1991). Shoot damage and growth losses following three years of Tomicus-attacks in Scots pine stands close to a timber storage site. Silva Fennica vol. 25 no. 3 article id 5450. https://doi.org/10.14214/sf.a15604
Keywords: Picea abies; growth; forest damage; Tomicus piniperda; Tomicus minor; timber storage; insect damages; shoots
Abstract | View details | Full text in PDF | Author Info

Shoot losses due to maturation feeding by pine shoot beetles (Tomicus piniperda (L.) and T. minor (Hart.), Col., Scolytidae) and subsequent growth losses were studied in Scots pine (Pinus sylvestris L.) stands growing at different distances from a timber yard, where pine timber was stored during the years 1982–84. In autumn 1985, pine trees were felled at 20, 40, 80, 500 and 1,500 m distance from the timber yard, five trees in each distance class. Trees were analysed for beetle attack, needle biomass and growth. In autumn 1988, increment cores were taken from 20 trees in each distance class.

In 1985, different damage estimates showed that beetle damage was more than 10-fold in the crowns of pine trees growing close to the timber yard as compared to less damaged trees in greater distance. Crude needle biomass estimates indicated that the trees attacked most had lost more than half of the total foliage. Following three years of attack, basal area growth decreased for 2–3 years and recovered during the subsequent 3 years, the total period of loss thus being 5–6 years. The loss in volume growth during 1983–85 was ca. 70, 40, 20 and 10% at 20, 40, 80 and 500 m distance from the beetle source, respectively, compared to the stand at 1,500. Growth losses did not occur until the number of beetle-attacks, ”pegs”, exceeded ca. 200 per tree. The highest observed growth losses occurred in trees with more than 1,000 pegs per tree.

The PDF includes an abstract in Finnish

  • Långström, E-mail: bl@mm.unknown (email)
  • Hellqvist, E-mail: ch@mm.unknown
article id 5434, category Article
Risto Heikkilä. (1990). Effect of plantation characteristics on moose browsing on Scots pine. Silva Fennica vol. 24 no. 4 article id 5434. https://doi.org/10.14214/sf.a15588
Keywords: Pinus sylvestris; Alces alces; moose; feeding behaviour; browsing damages; plantation characteristics
Abstract | View details | Full text in PDF | Author Info

The effects of plantation characteristics on moose (Alces alces) browsing intensity was studied in 82 Scots pine (Pinus sylvestris L.) plantations in Southern Finland. Moose browsing occurred most commonly in plantations established on relatively fertile soil, and the degree of damage was at highest in plantations with openings. A high amount of brush, especially aspen, increased the risk of damage. Furthermore, damage was intensified in plantations situated on hills, slopes or at a long distance from main roads or settlements.

The PDF includes an abstract in Finnish.

  • Heikkilä, E-mail: rh@mm.unknown (email)
article id 5427, category Article
Matti Nuorteva. (1990). Salama puustokuolemien aiheuttajana. Silva Fennica vol. 24 no. 2 article id 5427. https://doi.org/10.14214/sf.a15581
English title: Lightning as a cause of death of tree groups.
Original keywords: metsätuhot; salaman isku; kuolleet puut
English keywords: forest damage; lightning
Abstract | View details | Full text in PDF | Author Info

The writer reports in this discussion article of four stands in Finland that have died due to a bolt of lightning. A death of a group of trees because of lightning has been relatively uncommon for the forest professionals. The trees may not have no lightning marks. The four sites are presented in detail. Characteristic for this type of death of trees is, for instance, that trees have died within a circular area (of usually 30 m of diameter), only conifers have died, trees die from the top down, sometimes marks can be found in trees in the centre of the area, and under the bark may be brown patches or stripes.

  • Nuorteva, E-mail: mn@mm.unknown (email)
article id 5426, category Article
Juhani Päivänen. (1990). Pohjoisen havumetsävyöhykkeen suot ja niiden metsätaloudellinen hyväksikäyttö. Silva Fennica vol. 24 no. 2 article id 5426. https://doi.org/10.14214/sf.a15580
English title: Peatlands of the boreal zone and their utilization in forestry.
Original keywords: metsätalous; metsäojitus; suot; soiden ojitus; havumetsävyöhyke
English keywords: forestry; peatlands; drainage of peatlands; boreal zone
Abstract | View details | Full text in PDF | Author Info

The paper is a review on utilization of peatlands in forestry in the countries of boreal zone: Finland, Norway, Sweden, Canada, the United States and the Soviet Union. First, the concept of peatlands, the types of peatlands throughout the zone are defined, and the use of natural peatlands is described. Finally, the drainage of peatlands for forestry purposes in the countries is reviewed. According to the statistics, a total of 13 million ha of peatlands have been drained in Fennoscandia and the Soviet Union.

  • Päivänen, E-mail: jp@mm.unknown (email)
article id 5425, category Article
Hannu Saarenmaa. (1990). Frame- and rule-based knowledge representation in an expert system for integrated management of bark beetles. Silva Fennica vol. 24 no. 2 article id 5425. https://doi.org/10.14214/sf.a15579
Keywords: modeling; Scolytidae; expert systems; frame-based knowledge representation; integrated pest management
Abstract | View details | Full text in PDF | Author Info

Decision making in the forest protection involves diagnosing the pest, making predictions of the effects of the pest on forest, knowing the possible control tactics, and cost/benefit integration. To cope with all that, a generalist forest manager needs a tool like an expert system to support decisions.

This paper presents an expert system that approaches the goals of integrated pest management. With the systm, the user can make diagnosis and predictions of 12 North European bark beetles. Written in Common LISP and Flavors, the expert system has a combined frame- and rule-based knowledge representation. Frames are used to represent the hierarchy of insect taxonomy in diagnosis. Prediction is made with qualitative reasoning with rules. The interface engine applies both forward and backward chaining. The system has a graphical user interface that supports exploring the sensitivity of advice on input.

It is concluded that expert systems and artificial intelligence have high applicability everywhere in forestry where complicated decisions have to be made. Especially, an integrated pest management system in forestry is largely equivalent to a computerized decision-making aid.

The PDF includes an abstract in Finnish.

  • Saarenmaa, E-mail: hs@mm.unknown (email)
article id 5421, category Article
Tiina Tonteri. (1990). Inter-observer variation in forest vegetation cover assessments. Silva Fennica vol. 24 no. 2 article id 5421. https://doi.org/10.14214/sf.a15575
Keywords: vegetation survey; forest vegetation; canopy-coverage estimation
Abstract | View details | Full text in PDF | Author Info

Differences in vegetation cover estimation by field biologists of the 8th National Forest Inventory in Finland were tested. Eleven observers estimated the canopy coverages of six forests taxa in 25 sample plots, located in one stand. The experiment was arranged after the field work. The coverage of Vaccinium vitis-idaea and the ground layer appeared to be the most difficult to estimate. The mean of the highest estimator was about double that of the lowest one. The least abundant species and the sample plots with the smallest coverages had the largest estimation errors. The most important compositional gradient of the data was natural, even though the test was made in a homogenous area. However, the effect of the observer could be recognized. The differences between observers could be caused by the differences both in visual estimation level and in placing the sampling frame. The results suggest that tests should always be made when several observers are used in vegetation surveys. If calibration is used, it should be made separately for each species.

The PDF includes an abstract in Finnish.

  • Tonteri, E-mail: tt@mm.unknown (email)
article id 5419, category Article
Timo Pukkala, Owen Mubita, Jussi Saramäki. (1990). Management planning system for tree plantations. Silva Fennica vol. 24 no. 2 article id 5419. https://doi.org/10.14214/sf.a15573
Keywords: diameter distribution; plantations; yield model; Zambia; simulation model; Pinus kesiya; timber management planning; multiobjective optimization
Abstract | View details | Full text in PDF | Author Info

The paper presents a simple model of long-term forest management planning in tree plantations. The model is particularly suitable for developing countries where the research resources are limited. The management plan is prepared in two steps. First, one or several treatment schedules are simulated for each calculation unit (age class, compartment, etc.) over the selected planning period. Second, an optimal combination treatment schedules according to the selected objectives and constraints is searched by mathematical programming. The simulation of growth is based on the prediction of the diameter distribution at the desired time point. All stand characteristics are derived from this distribution. The models needed in the yield simulation can be estimated from temporary sample plots. A case study management plan for 13,000 ha of Pinus kesiya (Royle ex Gordon) plantations in Zambia is presented to demonstrate the system.

The PDF includes an abstract in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
  • Mubita, E-mail: om@mm.unknown
  • Saramäki, E-mail: js@mm.unknown
article id 5404, category Article
Pentti Alho. (1990). Suomen metsittyminen jääkauden jälkeen. Silva Fennica vol. 24 no. 1 article id 5404. https://doi.org/10.14214/sf.a15556
English title: The history of forests in Finland after the last ice age.
Original keywords: puulajit; jääkausi; metsittyminen; luonnonhistoria
English keywords: tree species; review articles; natural afforestation; ice age; natural history; post glacial
Abstract | View details | Full text in PDF | Author Info

Based on literature this paper describes the natural afforestation of Finland that took place after the last ice age and the changes which have taken place during the last 10,000 years. The origin and development of the vegetation and trees are related to the changes in the edaphic and climatic factors. The first tree species to arrive in Finland were the primary colonizing species, birch and Scots pine. The appearance of Norway spruce dates back to about 5000 B.P. There have been great changes in the species composition of Finnish forests during the last several thousands of years but some 2,000–3,000 years ago the various species reached their present balance. The epoch of naural forests, which had lasted some 9,500 years, came to a conclusion, however, when man started to have a marked effect on the forest’s development 300–400 years ago.

The PDF includes an abstract in English.

  • Alho, E-mail: pa@mm.unknown (email)
article id 5394, category Article
Pekka Kilkki. (1989). Kestävä metsätalous. Silva Fennica vol. 23 no. 4 article id 5394. https://doi.org/10.14214/sf.a15552
English title: Sustainable forest management.
Original keywords: metsänhoito; metsäekonomia; kestävä metsätalous
English keywords: forestry; sustainable forest management; forest economics
Abstract | View details | Full text in PDF | Author Info

This paper is a review on the development of sustainable forest management and what has been meant with the term in different times. The article summarises the birth of sustainable use of forests in the world and in Finland, and discusses sustainability in forest management, for instance from the point of view of one forest holding, large clearcuttings performed in Lapland, biological sustainability, business economics and overall planning.

  • Kilkki, E-mail: pk@mm.unknown (email)
article id 5393, category Article
Erkki Annila. (1989). Metsien kunto ja bioottiset tuhonaiheuttajat. Silva Fennica vol. 23 no. 4 article id 5393. https://doi.org/10.14214/sf.a15551
English title: Condition of forests and biotic damages .
Original keywords: metsätalous; hyönteistuhot; ilmastonmuutos; ilmansaasteet; sienituhot
English keywords: forestry; climatic change; insect damages; air pollution; fungal pathogens
Abstract | View details | Full text in PDF | Author Info

This review discusses whether forests are affected by biotic damages due to present or future environmental disturbances, and do environmental threats, such as air pollution and climatic change, weaken the condition of forest in a way that makes them vulnerable to damages by fungi and insect. The defence mechanisms of trees and factors affecting the development of an outbreak are described. Finally, the ways that air pollution and climatic change may affect biotic damages are discussed. 

  • Annila, E-mail: ea@mm.unknown (email)
article id 5370, category Article
Harri Rantonen, Juhani Päivänen. (1989). Kasvatusmetsien metsänhoidollinen tila ojitusalueilla puunkorjuun jälkeen. Silva Fennica vol. 23 no. 1 article id 5370. https://doi.org/10.14214/sf.a15529
English title: Silvicultural condition of tree stands after thinning on drained peatlands.
Original keywords: metsänhoito; harvennushakkuu; puunkorjuu; turvemaat; ojitetut suot; harvennusvoimakkuus
English keywords: forest management; harvesting; forest drainage; silviculture; drained peatland; thinning intensity
Abstract | View details | Full text in PDF | Author Info

The area of stands studied by line plot survey was 594 ha. On the basis of the length of the inventory line the estimated proportion of harvesting strips was 14% and that of ditch openings 6% of the area. The calculated strip road spacing was 29 m. The option of the minimum diameter made it difficult to use the number of stems as criterion for thinning intensity. Thinning intensity evaluated according to the basal area had been stronger than recommended with low values of dominant height and milder with high values. The estimated removal according to stumps was 38 m3/ha on the average between the strips. The real removal has, however, been larger than that, as the strip road openings are made in connection with the first thinning.

The PDF includes an abstract in English.

  • Rantonen, E-mail: hr@mm.unknown (email)
  • Päivänen, E-mail: jp@mm.unknown
article id 5362, category Article
Seppo Kellomäki, Heikki Hänninen, Taneli Kolström. (1988). Model computations on the impacts of the climatic change on the productivity and silvicultural management of the forest ecosystem. Silva Fennica vol. 22 no. 4 article id 5362. https://doi.org/10.14214/sf.a15519
Keywords: boreal forests; adaptation; simulation; climatic change; future silviculture; changing environment; pest management
Abstract | View details | Full text in PDF | Author Info

The model computations indicate that the climatic change in the form of higher temperatures and more precipitation could increase the productivity of the forest ecosystem and lead to higher rates of regeneration and growth. More frequent and intensive thinnings are needed to avoid the mortality of trees induced by accelerated maturation and attacks of fungi and insects. The climatic change could support the dominance of deciduous tree species and necessitate an intensification of the tending of seedling stands of conifers. The rise of air temperature during autumn and winter could change also the annual growth rhythm of trees and result in dehardening and subsequent frost damages and attacks of insects and fungi. The pest management could be the greatest challenge to the future silviculture, which could be modified most in Northern Finland.

The PDF includes an abstract in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Hänninen, E-mail: hh@mm.unknown
  • Kolström, E-mail: tk@mm.unknown
article id 5355, category Article
Halvor Rostad. (1988). Frost resistance during shoot elongation in Picea abies seedlings in relation to the growth environment of the previous growing period. Silva Fennica vol. 22 no. 3 article id 5355. https://doi.org/10.14214/sf.a15512
Keywords: Norway spruce; Picea abies; frost damages; cold tolerance; nursery stock; late-frost resistance; physiological status; hardiness development; irradiation
Abstract | View details | Full text in PDF | Author Info

Frost resistance during shoot elongation in seedlings of Norway spruce (Picea abies (L.) H. Karst.) was studied in two experiments. The aim of the first study was to evaluate the effect of varying mineral nutrition. Except for potassium, only minor differences in mineral elements concentrations were established, presumably due to low levels of irradiance and thus a low rate of dry matter production. No significant differences in frost injuries were found between the treatments in the experimental series, but the control seedlings were significantly less injured. It is assumed that poor hardiness development at the end of one growth period resulting from low levels of irradiance may decrease the frost resistance during the next shoot elongation phase. Observations from the second experiment with Norway spruce nursery stocks representing different seedling ages and production systems, support this assumption.

The PDF includes an abstract in Finnish.

  • Rostad, E-mail: hr@mm.unknown (email)
article id 5352, category Article
Lars Christersson, Heinrich A. von Fircks. (1988). Injuries to conifer seedlings caused by simulated summer frost and winter desiccation. Silva Fennica vol. 22 no. 3 article id 5352. https://doi.org/10.14214/sf.a15509
Keywords: Pinus sylvestris; Picea abies; Picea mariana; conifers; frost damage; Sweden; Pinus contorta; seedlings; cold tolerance; frost hardiness in growing phase; winter desiccation
Abstract | View details | Full text in PDF | Author Info

Visible frost damage to forest trees in Sweden seldom occurs in winter but is frequent in late spring, summer and early autumn. Frosts are frequent in all seasons in various parts of Sweden, even in the southernmost part (lat. 56°, N) and temperatures may be as low as -10°C even around mid-summer. Ice crystal formation within the tissues, which in most seedlings takes place at around -2°C, causes injury, not the sub-zero temperatures themselves.

The apical meristem, the elongated zone, and the needles of seedlings of Picea abies (L.) H. Karst. in a growing phase were damaged at about -3°C and those of Pinus sylvestris L. at about -6°C. Other species of the genus Pinus were tested and most were found to be damaged at about -6°C, with some variations. Picea species tested were damaged at about -3°C to -4°C.

A method has been designed to compare the response of different species to winter desiccation, which occurs under conditions of (1) low night temperature, (2) very high irradiation and increase in needle temperature during the photoperiod, (3) frozen soil, and (4) low wind speed. There were differences in response to winter desiccation between pine and spruce species. Seedlings of Pinus contorta tolerated these winter desiccation conditions much better than those of P. sylvestris or Picea abies. Picea mariana was the least tolerant of the species tested.

The PDF includes an abstract in Finnish.

  • Christersson, E-mail: lc@mm.unknown (email)
  • Fircks, E-mail: hf@mm.unknown
article id 5351, category Article
Tapani Repo. (1988). Physical and physiological aspects of impedance measurements in plants. Silva Fennica vol. 22 no. 3 article id 5351. https://doi.org/10.14214/sf.a15508
Keywords: developmental stage; electrical impedance; cross-sectional area; frost resistance; temperature acclimation; physiology
Abstract | View details | Full text in PDF | Author Info

Electrical impedance characteristics of plant cells are dependent on such physiological factors as physiological condition, developmental stage, cell structure, nutrient status, water balance and temperature acclimation. In the measurements also such technical and physical factors as type of electrodes, frequency, geometry of the object, inter-electrode distance and temperature have an effect. These factors are discussed especially with respect to the impedance method in frost resistance studies of plants.

The PDF includes an abstract in Finnish.

  • Repo, E-mail: tr@mm.unknown (email)
article id 5350, category Article
Heikki Hänninen, Paavo Pelkonen. (1988). Frost hardiness and over-wintering of forest trees. Silva Fennica vol. 22 no. 3 article id 5350. https://doi.org/10.14214/sf.a15507
Keywords: frost hardiness; breeding; frost damage; genetic variation; dormancy; annual cycle of development; nursery management
Abstract | View details | Full text in PDF | Author Info

This issue of Silva Fennica consists of eight articles, which are based on a co-nordic conference ”Frost hardiness and over-wintering in forest tree seedlings”, held in Joensuu, Finland, during December 1–3, 1986. The whole annual cycle of the trees is considered. Emphasis is given on methods for the study of frost hardiness, genetic variation in frost hardiness, nitrogen metabolism, bud dormancy release, and joint effect of natural and anthropogenic stress factors in the winter damage of forest trees. Practical implications for tree breeding and nursery management are discussed.

The PDF includes an abstract in Finnish.

  • Hänninen, E-mail:
  • Pelkonen, E-mail:
article id 5346, category Article
Timo Pukkala. (1988). Methods to incorporate the amenity of landscape into forest management planning. Silva Fennica vol. 22 no. 2 article id 5346. https://doi.org/10.14214/sf.a15503
Keywords: forest management; landscape management; multipurpose forestry; multiobjective planning; computer simulation; mathematical optimization; management plan
Abstract | View details | Full text in PDF | Author Info

The study presents methods that incorporate the amenity of a forest area into the management planning. The management plan is based on treatment schedules simulated for each compartment over the 20-year planning period. The best combination of treatment schedules is selected by multi-objective optimization. The amenity is divided into two parts: (1) within-stand amenity and (2) the amenity of landscape when viewed afar (distant scene). The within-stand amenity is expressed in terms of adjective sum which is estimated from stand characteristics. The adjective sum of the whole area in a selected year can be taken as an objective or constraining variable of optimization. The assessment of the distant scene is based on computer illustrations which show the predicted temporal change of landscape according to a particular management plan.

The PDF includes a summary in Finnish.

  • Pukkala, E-mail: tp@mm.unknown (email)
article id 5341, category Article
Hannu Hökkä, Jukka Laine. (1988). Suopuustojen rakenteen kehitys ojituksen jälkeen. Silva Fennica vol. 22 no. 1 article id 5341. https://doi.org/10.14214/sf.a15498
English title: Post-drainage development of structural characteristics in peatland forest stands.
Original keywords: metsikön rakenne; turvemaat; ojitetut suot; eri-ikäisrakenne; runkoluku; läpimittajakauma
English keywords: stand structure; drained peatlands; diameter distribution; forest drainage; uneven-aged structure
Abstract | View details | Full text in PDF | Author Info

The effect of drainage on structure of tree stands is analysed by comparing the average structural characteristics (e.g. diameter distribution) of stands in the data for different drainage age classes and selected site types. The material consists of ca. 4,400 relascope sample plots, which are part of a large drainage area inventory project. The uneven-aged structure of the virgin peatland forest is preserved for several decades after drainage. This is enhanced by the post-drainage increase of small-diameter trees, especially birch. The number of trees per hectare increased during a period of ca. 30 years and levelled off thereafter. The increase in the number of saw log stems is clearly related to the fertility of the site and its geographical location.

The PDF includes a summary in English.

  • Hökkä, E-mail: hh@mm.unknown (email)
  • Laine, E-mail: jl@mm.unknown
article id 5319, category Article
Heikki Hänninen. (1987). Effects of temperature on dormancy release in woody plants. Silva Fennica vol. 21 no. 3 article id 5319. https://doi.org/10.14214/sf.a15476
Keywords: temperature; bud burst; dormancy; annual cycle of development; dormancy breaking; chilling requirement; rate of development; rest period; simulation model; stage of development
Abstract | View details | Full text in PDF | Author Info

Logical structure of three simulation models and one conceptual model concerning effects of temperature on dormancy release in woody plants was examined. The three basic types of simulation models differed in their underlying assumptions. Contrasting implications of the models were inferred by deduction. With the aid of these implications, the model types can be tested using experiments with continuous and interrupted chilling. Similarly, implications of the conceptual model of rest phases were inferred, by which the model can be tested using experiments with continuous chilling and forcing in multiple temperatures. The possibilities to synthetize the conceptual model with any of the three simulation model types, as well as the biological interpretation of the model variables, were discussed.

The PDF includes an abstract in Finnish.

  • Hänninen, E-mail: hh@mm.unknown (email)
article id 5315, category Article
Seppo Kellomäki, Matti Seppälä. (1987). Simulations on the effects of timber harvesting and forest management on the nutrient cycle and productivity of Scots pine stands. Silva Fennica vol. 21 no. 2 article id 5315. https://doi.org/10.14214/sf.a15472
Keywords: Pinus sylvestris; forest management; productivity; fertilization; nitrogen; simulation; rotation; timber harvest; nitrogen cycle
Abstract | View details | Full text in PDF | Author Info

Effects of varying rotation, thinning, fertilization and harvest intensity on the productivity and nitrogen cycle of Scots pine (Pinus sylvestris L.) stand were studied on the basis of computer simulation. The increasing intensity of management increased the loss of nitrogen in the cycle. Short rotation, associated with early thinning by means of the whole tree harvest, proved to be especially detrimental regarding the productivity of the forest ecosystem. Fertilization associated with thinnings is of great importance in maintaining the productivity of a forest ecosystem during an intensive timber harvest.

The PDF includes an abstract in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
  • Seppälä, E-mail: ms@mm.unknown
article id 5299, category Article
Shigeru Shimotori. (1986). Private and municipal forests and the forestry planning system in Japan - trends and problems after World War II. Silva Fennica vol. 20 no. 4 article id 5299. https://doi.org/10.14214/sf.a27755
Keywords: forest management; forest owners; forest resources; private forestry; Japan; forestry policy; forestry planning system
Abstract | View details | Full text in PDF | Author Info

In this paper, the author explains the characteristics of the Japanese forestry planning system and points out some of the problems found therein from the viewpoint of the management of privately-owned forests relating to the economic background and governmental policy.

The forestry planning system is a centralizes type of planning, the planning begins at the top and flows downward and outward the periphery. In order to make this planning system an effective instrument, the district forestry planning founded under the system must approach the problem of how to combine the resources of the forest with the district’s inhabitants and the forest owners; and further, the extent of the effective union of the district and the local timber manufacturing must be examined.

  • Shimotori, E-mail: ss@mm.unknown (email)
article id 5298, category Article
Frederick W. Cubbage, Donald G. Hodges. (1986). Public and private technical assistance programs for non-industrial private forest landowners in the southern United States. Silva Fennica vol. 20 no. 4 article id 5298. https://doi.org/10.14214/sf.a27754
Keywords: forest management; forest policy; private forestry; United States; forest extension; forest advisory services; forest consulting; forest management plans; supervision
Abstract | View details | Full text in PDF | Author Info

Non-industrial private landowners hold about two-thirds of the forest land in the southern United States. The types of public (state) and private (consulting and industrial) assistance offered to these owners is reviewed. In total, about 1,600 foresters in the South provide management assistance to non-industrial private forest owners. They assist at least 72,000 owners annually, including provision of management plans for about 10 million acres and supervision of over 4 million acres of leased lands.

  • Cubbage, E-mail: fc@mm.unknown (email)
  • Hodges, E-mail: dh@mm.unknown
article id 5296, category Article
Russell K. Henly, Paus V. Ellefson. (1986). Cost and effectiveness of legal mandates for the practice of forestry on private land. Silva Fennica vol. 20 no. 4 article id 5296. https://doi.org/10.14214/sf.a27752
Keywords: forest management; forest policy; forest legislation; private forestry; United States; forest laws; regulation of forest practices; protection of forest resources
Abstract | View details | Full text in PDF | Author Info

Comprehensive state laws regulating the practice of forest management on private lands are in effect in seven of the United States. Established to protect a wide range of non-timber forest resources and to ensure reforestation after harvest, these laws may impose significant administrative costs on states and significant compliance costs on landowners and timber operators. Total state administration costs for 1984 are estimated at $10.1 and total private sector compliance costs are estimated at $120.5 million, for a total regulation cost of $130.6 million.

The resource protection effectiveness of state forest practice regulation is difficult to quantify. However, agreement is strong that regulation has led to significant improvements in forest resource conditions and has helped to increase reforestation.

  • Henly, E-mail: rh@mm.unknown (email)
  • Ellefson, E-mail: pe@mm.unknown
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 5288, category Article
Christopher D. Risbrudt. (1986). Policy evaluations for U.S. federal timber sale accounting system development. Silva Fennica vol. 20 no. 4 article id 5288. https://doi.org/10.14214/sf.a27744
Keywords: forest policy; forest administration; United States; economic evaluation; timber sale accounting system; timber management
Abstract | View details | Full text in PDF | Author Info

Development of timber sale accounting system for the U.S. Department of Agriculture, Forest Service ordered by the U.S. Congress, has entailed numerous evaluations and research projects. Critics of the current process claims administrative costs are not recovered by the prices paid for Federal timber. However, management of multiple resources for multiple uses makes traditional accounting difficult; i.e., keeping track of cash flows. A further complication involves allocating costs to the various resources (joint cost allocation), for which no nonarbitrary method currently exists. A concurrent issue involves the building of roads for timber harvest into areas released from wilderness consideration. Environmentalists see the road building program of the Federal land management agencies as an additional reason Federal management costs are not recovered from timber-generated revenues. The heart of the issue is which lands are economically suited for timber management, and what nonmarket benefits and costs accrue from the timber management.

  • Risbrudt, E-mail: cr@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 5276, category Article
Kari Heliövaara, Rauno Väisänen. (1986). Parasitization in Petrova resinella (Lepidoptera, Tortricidae) galls in relation to industrial air pollutants. Silva Fennica vol. 20 no. 3 article id 5276. https://doi.org/10.14214/sf.a15455
Keywords: Pinus sylvestris; Scots pine; insect damages; air pollution; Petrova resinella; gall stage; parasites
Abstract | View details | Full text in PDF | Author Info

Paratization of Petrova resinella L. in the gall stage was studied in the surrounding of Harjavalta, south-western Finland, in relation to industrial air pollution. Of the studied 283 galls, 28% produced a moth, 52% of the larvae/pupae were paratisized, and 20% were empty or contained a dead larva. The proportion of paratisized galls did not depend on the distance from emission sources of industrial air pollutants.

The PDF includes an abstract in Finnish.

  • Heliövaara, E-mail: kh@mm.unknown (email)
  • Väisänen, E-mail: rv@mm.unknown
article id 5273, category Article
Raymond K. Omwami. (1986). A theory of stumpage appraisal. Silva Fennica vol. 20 no. 3 article id 5273. https://doi.org/10.14214/sf.a15452
Keywords: silviculture; growing stock; stumpage prices; forest economy; stumpage longevity; bilateral monopoly; rational expectations
Abstract | View details | Full text in PDF | Author Info

This paper is a theoretical study of what is considered to constitute the proper perception of time in forest economics and management. A stumpage appraisal model that recognizes the influence of time is developed within the framework of a national aggregate economy. To demonstrate how a socially optimal land for timber production may be determined in a given nation, a stock-supply model is derived. The stumpage appraisal rule of development determines the market stumpage price that maintains a state of balance between timber production and other land use activities.

The PDF includes an abstract in Finnish.

  • Omwami, E-mail: ro@mm.unknown (email)
article id 5264, category Article
Kari Heliövaara. (1986). Occurrence of Petrova resinella (Lepidoptera, Tortricidae) in a gradient of industrial air pollutants. Silva Fennica vol. 20 no. 2 article id 5264. https://doi.org/10.14214/sf.a15443
Keywords: Pinus sylvestris; Harjavalta; insect damages; air pollution; Petrova resinella; galls
Abstract | View details | Full text in PDF | Author Info

The relationship between industrial air pollutants and the occurrence of galls of Petrova resinella (Lepidoptera, Torticiadae) was studied around the industrialized town of Harjavalta in Western Finland. There were 44 sampling sites set out at logarithmic distances along five transects (NW, W, SW, SE) froma a distive source of emissions. Each site consisted of three circular sample plots (30 m2) in young Scots pine (Pinus sylvestris L.) stands. The number of galls, including cankers from several years earlier, was highest in the vicinity of the factory complex on each transect. The highest number of two-year-old galls containing living larvae was usually recorded at the ends of the transects several kilometres from the factories. However, the significance of the differences both between zones and transects was rather low. Correlations between the deposition of heavy metals (Cd, Cu, Ni, Pb, Zn), used as an indication of the general level of air pollution, and the total number of galls, were positive and generally highly significant. It is concluded that P. resinella has benefitted from air pollution although perhaps to less extent than some sap-sucking species.

The PDF includes an abstract in Finnish.

  • Heliövaara, E-mail: kh@mm.unknown (email)
article id 5262, category Article
Markku Nygren. (1986). Männyn siementen syyskeräys. Silva Fennica vol. 20 no. 1 article id 5262. https://doi.org/10.14214/sf.a15441
English title: Autumn harvested Scots pine seeds: the effect of cone storage and germination conditions on germination capacity.
Original keywords: mänty; itävyys; dormanssi; siemenkeräys; lepotila; käpyjen varastointi
English keywords: Pinus sylvestris; Scots pine; germination capacity; seed dormancy; cone storage
Abstract | View details | Full text in PDF | Author Info

Six seed collections were made in September–December 1984 in a natural Scots pine (Pinus sylvestris L.) stand in Southern Finland. The seeds were germinated immediately after the cone collection and three photoperiods (0.8 and 24 hours) were used in germination tests.

The seeds collected in September and October possessed relative dormancy, i.e. they did not germinate in darkness and at 10°C. Later in November and December the seeds were capable to germinate in darkness and at low temperature also. The gradual change in germination capacity is attributed to chilling temperatures in natural environments or in cone storage.

The PDF includes a summary in English.

  • Nygren, E-mail: mn@mm.unknown (email)
article id 5260, category Article
The Forest 2000 Programme sub-commitee. (1986). The Forest 2000 Programme in Finland. Silva Fennica vol. 20 no. 1 article id 5260. https://doi.org/10.14214/sf.a15439
Keywords: forest management; forest policy; Finland; timber production; forest industries; annual cut; forestry development; cutting target
Abstract | View details | Full text in PDF | Author Info

The Forest 2000 Programme is a long-term programme for forestry and the forest industries in Finland. It attempts to obtain a better integration of timber production and other forms of forest use. The total annual cut is to be increased by 15 million m3 by the year 2010. This is almost one third greater than the level during the first few years of the 1980’s. In order to achieve the cutting targets, the cut area will have to be increased by almost one third by the turn of the century. The area of thinnings will experience the greatest increase. Considerable changes are proposed in silvicultural and basic improvement work. According to the programme, the growth of the raw-material base and the consumption of the wood-based products will permit an annual increase of about 3% in the production of the forest industries as a whole until the end of the century. This would be the same as the target growth rate of the GNP.

The PDF includes an abstract in Finnish.

  • The Forest 2000 Programme sub-commitee, E-mail:
article id 5252, category Article
Kari Löyttyniemi. (1985). On repeated browsing of Scots pine saplings by moose (Alces alces). Silva Fennica vol. 19 no. 4 article id 5252. https://doi.org/10.14214/sf.a15431
Keywords: Pinus sylvestris; Scots pine; Finland; Alces alces; moose; seedling damages; browsing damage; elks
Abstract | View details | Full text in PDF | Author Info

The size, nutrient contents and terpene composition of needles of Scots pine (Pinus sylvestris L.) saplings untouched and repeatedly browsed by the moose (Alces alces L.) were compared. Material was collected from a 14-years old and 2.5 m high pine stand in Bromarv, Southern Finland. The average length and fresh and dry weight of the needles were measured, and nutrient content (N, P, K, Ca, Mg, B, Cu) was determined.

The needles of repeatedly browsed pines became long and robust. There was, however, no difference between the dry matter percentage between the needles. The average nitrogen content was higher in the rebrowsed trees. Nitrogen content is, however, not directly correlated with the palatability of pine needles. Even phosphorus and boron content were higher in the damaged trees. No difference was found in Ca, K, Mg and Cu contents of the browsed and control pine saplings.

The PDF includes a summary in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 5239, category Article
Jussi Kuusipalo. (1985). On the use of tree stand parameters in estimating light conditions below the canopy. Silva Fennica vol. 19 no. 2 article id 5239. https://doi.org/10.14214/sf.a15418
Keywords: Pinus sylvestris; basal area; Picea abies; canopy; tree species composition; light conditions; light climate; number of stems; canopy coverage
Abstract | View details | Full text in PDF | Author Info

Especially in forest vegetation studies, the light climate below the canopy is of great interest. In extensive forest inventories, direct measurement of the light conditions is too time-consuming. Often only the standard tree stand parameters are available. The present study was undertaken with the aim to develop methods for estimation of the light climate on the basis of readily measurable tree stand characteristics. The study material includes 40 sample plots representing different kinds of more or less mature forest stands of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.).

In each forest stand, a set of hemipherical photographs was taken and standard tree stand measurements were performed. A regression approach was applied in order to elaborate linear models for predicting the canopy coverage. The total basal area of the stand explained 63% of variance in the canopy coverage computed from hemipherical photographs. A coefficient representing the relative proportion of Norway spruce in the stand increased the explanatory power into 75%. When either the stand density (stems/unit area) or dominant age of the stand was included into the model, increment of the explanatory power into 80% was achieved. By incorporating both of the preceding predictors, an explanatory power of 85% was reached.

The PDF includes a summary in Finnish.

  • Kuusipalo, E-mail: jk@mm.unknown (email)
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 5234, category Article
Eino Mälkönen, Eero Paavilainen. (1985). Hydrological amelioration and forest practice on drained peatlands. Silva Fennica vol. 19 no. 2 article id 5234. https://doi.org/10.14214/sf.a15413
Keywords: drainage; peatlands; peatland forestry; hydrology; forest research; bibligraphies
Abstract | View details | Full text in PDF | Author Info

This bibliography consists of monographs, papers published in periodicals and journals and collections of scientific papers from research and educational institutes, and transactions from scientific congresses, seminars, symposia and meetings.

The publications have been divided into three basic sections. In each section the publications are listed in alphabetical order by the author(s) or title. The total number of the titles in this bibliography is 465.

  • Mälkönen, E-mail:
  • Paavilainen, E-mail:
article id 5233, category Article
Leo Heikurainen. (1985). Verhopuuston vaikutus kuusitaimikon kehitykseen. Silva Fennica vol. 19 no. 1 article id 5233. https://doi.org/10.14214/sf.a15412
English title: The influence of birch nurse crop (Betula pubescens) on the growth of Norway spruce (Picea abies) seedling stands on drained peatlands.
Original keywords: kuusi; metsänhoito; kasvu; ojitetut suot; suojapuusto; pakkasvauriot; hieskoivu; verhopuusto; verhopuuston tiheys; verhopuuston poisto
English keywords: forest management; Norway spruce; Picea abies; Betula pubescens; tree growth; frost damages; nurse stand
Abstract | View details | Full text in PDF | Author Info

Young Norway spruce (Picea abies (L.) H. Karst.) are susceptible to early summer frost damage. Birch (Betula pubescens Ehrh.) naturally colonize rich or fairly rich drained peatlands after clear cutting, and can provide protection for developing seedlings. The report describes the development of spruce stands after various types of handing of the birch nurse crops.

Different proportions of birch and spruces did not have any influence on the spruce stand production. In cases where the nurse crop stand is removed when the spruce stand age was 20 years and height 4 m the spruce suffered badly but recovered with time, reaching the spruce stand growing under a nurse stand within the next 20 years. The height growth of spruce depends on the density of the nurse stand, especially on fertile sites. The development of diameter growth also depends on the density of the nurse trees. Removal of the nurse stand in spruce stands on the sites concerned should be done when the spruce stand is 20 years old and at the height of 4 m.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@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 5230, category Article
Erkki Kaila. (1985). Havaintojen käsittely ja aineiston muodostus metsäntutkimuksen tiedonhallinnan näkökulmasta. Silva Fennica vol. 19 no. 1 article id 5230. https://doi.org/10.14214/sf.a15409
English title: Observation manipulation and data matrix derivation from the viewpoint of data management.
Original keywords: metsäntutkimus; tietokannat; tiedonhallinta; tietokantaohjelmat
English keywords: forest research; data bases; data management
Abstract | View details | Full text in PDF | Author Info

Data management is pointed out as a phase of research process. It covers research activities from observation recording to data matrix derivation. Some concepts of logical and physical database implementation are introduced.

The TUTKA -software system is introduced and observed as an instrument of research data management. Attention is paid to TUTKA’s five design criteria. Database implementation and use with TUTKA are observed precisely. Three different phases of implementing a data base are specified. Finally, some aspects to the data management of forest research are presented.

The PDF includes a summary in English.

  • Kaila, E-mail: ek@mm.unknown (email)
article id 5229, category Article
Maija-Liisa Juntunen, Jan Engsås, Lennart Gustafsson, Pekka Mäkinen, Frans Theilby, Tore Vik. (1985). Supervisors in the forestry of the Nordic countries. Silva Fennica vol. 19 no. 1 article id 5229. https://doi.org/10.14214/sf.a15408
Keywords: forestry; Nordic countries; Finland; Norway; Sweden; Denmark; forest education; wages; supervisors; foremen; pay system
Abstract | View details | Full text in PDF | Author Info

The goal of this research was to study the position of forest supervisors, their education, number, pay system, professional organizations and work situations in Nordic countries. The study belonged to a joint Nordic project of the Nordic Research Council on Forest Operations. Participating in the actual work the number of forest supervisors were Denmark (year 1978) 715, Finland (1980) 8,000, Norway (1967) 1,055, and Sweden (1975) 6,400. In Denmark, 87% of the supervisors worked in forestry, in Finland 91%, in Norway 98% and in Sweden 86%.

Forest supervisor education started at the end of the last century. In the 1950s and 1960s the forest supervisors’ education has been renewed in all four countries. Supervisors have a special 1 to 4.5 years’ training, but many have a forest technician’s education, too. In Finland and Sweden forest supervisor education was reformed at the end of the 1970s. Supervisors work in functional as well as in regional organizations. In Nordic countries, supervisors are paid monthly salaries. Salaries are a little higher in private than in public sector companies. In 1981 the start salary in Finland was 3,107 FIM and in Sweden in 1980 about 4,425 FIM. Most supervisors in the Nordic countries belong to some union.

The PDF includes a summary in English.

  • Juntunen, E-mail: mj@mm.unknown (email)
  • Engsås, E-mail: je@mm.unknown
  • Gustafsson, E-mail: lg@mm.unknown
  • Mäkinen, E-mail: pm@mm.unknown
  • Theilby, E-mail: ft@mm.unknown
  • Vik, E-mail: tv@mm.unknown
article id 5223, category Article
Eino Mälkönen, Finnish Society of Forest Science. (1984). Metsäntutkimus metsätalouden tietopohjana. Silva Fennica vol. 18 no. 4 article id 5223. https://doi.org/10.14214/sf.a15402
English title: The role of forestry research in providing a scientific basis for practical forestry.
Original keywords: metsätieteet; metsäntutkimus; metsätalous; Suomi
English keywords: forest management; forestry; Finland; forest research; forest sciences
Abstract | View details | Full text in PDF | Author Info

The Society of Forestry in Finland (now the Finnish Society of Forest Science) arranged on 26th April 1984 a Forestry Science Day centred on the theme ”The role of Forestry Research in Providing a Scientific Basis for Practical Forestry”. Specialists in forestry and forest policy reviewed the role, present situation and future tasks of forest research from different points of view, in their papers. This article includes the talks given in the event in Finnish and an English summary.

  • Mälkönen, E-mail:
  • Finnish Society of Forest Science, E-mail:
article id 5222, category Article
Matti Leikola, Aune Koponen. (1984). Metsätalouden harjoittaminen ja metsien hoito. Silva Fennica vol. 18 no. 4 article id 5222. https://doi.org/10.14214/sf.a15401
English title: Forestry in Finland. Studia Forestalia 1983.
Original keywords: metsäntutkimus; metsänhoito; metsätalous; luentosarja
English keywords: forest management; forestry; Finland; forest research; course of lectures
Abstract | View details | Full text in PDF | Author Info

1983 was the so-called ”Year o the Forest” in Finland. To mark the occasion, the Society of Forestry in Finland (now the Finnish Society of Forest Science) arranged a series of Studia Forestalia lectures which covered, in general form, a wide range of subjects. 12 of the 14 lectures given in this series are included in this edition.

The PDF includes a summary in English.

  • Leikola, E-mail:
  • Koponen, E-mail:
article id 5221, category Article
Aleksandr P. Jevdokimov. (1984). Visakoivun kasvatus Neuvostoliiton luoteisosissa. Silva Fennica vol. 18 no. 3 article id 5221. https://doi.org/10.14214/sf.a15400
English title: Experiences of curly birch growing in north-western Russia.
Original keywords: metsänhoito; Neuvostoliitto; visakoivu; Neuvosto-Karjala; Leningrad
English keywords: forest management; Soviet Union; Betula pendula var. carelica; curly birch; Soviet Karelia; Leningrad region
Abstract | View details | Full text in PDF | Author Info

Curly birch (Betula pendula var. carelica (Merklin) Hejtmanek) is widely distributed over north-western part or Russia, including the Baltic Soviet Republics and Belorussia. Experiences of growing this decorative species in Soviet Karelia and Leningrad region are presented. Commonly used classifications of the species are described, and recommendations for management of curly birch cultures and production of planting stock in greenhouses are given.

The PDF includes a summary in English.

  • Jevdokimov, E-mail: aj@mm.unknown (email)
article id 5220, category Article
Peitsa Mikola. (1984). Harsintametsätalous. Silva Fennica vol. 18 no. 3 article id 5220. https://doi.org/10.14214/sf.a15399
English title: Selection system in timber harvesting in Finland.
Original keywords: kuusi; metsänhoito; harsinta; eri-ikäiskasvatus; eri-ikäisrakenteinen metsä; tasaikäiskasvatus; tasa-ikäinen metsä
English keywords: forest management; Norway spruce; Picea abies; yield; Finland; selection system; even-aged stands; selection cuttings; uneven-aged stands
Abstract | View details | Full text in PDF | Author Info

This article reviews experiments and practical experience of forest management by the selection system in Finland. In an experiment of 25-year duration the annual growth of uneven-aged Norway spruce (Picea abies (L.) H. Karst.) stands was only about 50% of the average annual yield of even-aged stands in normal rotation on the same site.

In Finland the selection system is applicable under exceptional conditions only, viz. In intensively managed park stands and, on the other hand, on very marginal sites, e.g. on peat bogs and mountains near the tree-line. Even normal silviculture, however, may include cuttings which somewhat resemble selection system, e.g. removal of standards or restoration of mismanaged forests.

The PDF includes a summary in English.

  • Mikola, E-mail: pm@mm.unknown (email)
article id 5219, category Article
Simo Poso, Tuomas Häme, Raito Paananen. (1984). A method for estimating the stand characteristics of a forest compartment using satellite imagery. Silva Fennica vol. 18 no. 3 article id 5219. https://doi.org/10.14214/sf.a15398
Keywords: forest inventories; remote sensing; satellite imagery; survey by stands; compartmentwise forest inventories; relascope plots
Abstract | View details | Full text in PDF | Author Info

The paper presents a method based on two phase sampling and applicable to forest inventories. The first phase estimates are obtained from satellite imagery and, if required, from extra material such as maps. Second phase estimates are measured in the field. The method is flexible and also applicable to compartmentwise forest inventories. The experiments were based on six study areas with 439 relascope plots. The correlation coefficients between first and second stage estimates varied largely according to the study area.

The PDF includes a summary in Finnish.

  • Poso, E-mail: sp@mm.unknown (email)
  • Häme, E-mail: th@mm.unknown
  • Paananen, E-mail: rp@mm.unknown
article id 5218, category Article
Jouni Suoheimo. (1984). Isokorvakärsäkkään aikuisten esiintyminen ja merkitys männyn luontaiselle uudistamiselle Pohjois-Lapissa. Silva Fennica vol. 18 no. 3 article id 5218. https://doi.org/10.14214/sf.a15397
English title: The occurrence of Otiorrhynchus nodosus and its significance for the natural regeneration of Scots pine in Lapland.
Original keywords: hyönteistuhot; mänty; luontainen uudistaminen; taimituhot; Pohjois-Lappi; isokorvakärsäkäs
English keywords: Pinus sylvestris; natural regeneration; Scots pine; insect damage; seedling damages; weevils; occurrence
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to survey the occurrence of Otiorrhynchus nodosus Müller weevils and their significance for the natural regeneration of Scots pine (Pinus sylvestris L.). The study was carried out during summer 1982 at Inari in northern Lapland.

There were two sample plots, one situated in a Scots pine seed-tree area and the other, the control sample plot, in an area with a coverage of mountain birch (Betula pubescens subsp. tortuosa, now subsp. czerepanovii). A total of 177 Otiorhynchus weevils were caught. Movement of the weevils reached its climax in July. There were 86% more individuals in the seed-tree area than in the mountain birch area. No damage to the pine germlings or seedlings was not observed, although the situation could be different during the peaks of the veewil populations.

The PDF includes a summary in English.

  • Suoheimo, E-mail: js@mm.unknown (email)
article id 5213, category Article
Bo Långström. (1984). Windthrown Scots pines as brood material for Tomicus piniperda and T. minor. Silva Fennica vol. 18 no. 2 article id 5213. https://doi.org/10.14214/sf.a15392
Keywords: Pinus sylvestris; bark beetles; Scots pine; wind damages; breeding; Sweden; Tomicus piniperda; Tomicus minor; insect damage; egg galleries
Abstract | View details | Full text in PDF | Author Info

In the 1980 and 1981, windthrown and felled Scots pine (Pinus sylvestris L.) were examined at 8 localities in Sweden. The number and length of egg galleries as well as the number of exit holes of Tomicus piniperda (L.) and T. minor (Hart.) were recorded on sample sections (30 m in length) distributed at 3 m intervals on the 37 fallen pine stems, which were successfully colonized by the beetles. In addition, 78 uprooted pines were surveyed in 6 localities. Most trees were attacked by T. piniperda, but only a few by T. minor. Successful colonization often resulted in the production of several thousand beetles per tree, the maximum being approximately 1,800. The attack density of T. piniperda seldom exceeded 200 egg galleries/m3 bark area, and the brood production usually remained below 1,000 beetles/m3. Much higher figures were obtained or T. minor. In T. piniperda, the rate of reproduction (i.e. the number of exit holes /egg gallery) decreased rapidly with increasing attack density, whereas T. minor seemed to be less sensitive to intraspecific competition.

The PDF includes a summary in Finnish.

  • Långström, E-mail: bl@mm.unknown (email)
article id 5206, category Article
Matti Kärkkäinen. (1984). Miten koivuun tulisi suhtautua metsätaloudessa? Silva Fennica vol. 18 no. 1 article id 5206. https://doi.org/10.14214/sf.a15385
English title: The proper attitude towards birch in forestry.
Original keywords: metsänhoito; metsätalous; kannattavuus; koivu
English keywords: forest management; Betula; forestry; profitability
Abstract | View details | Full text in PDF | Author Info

A literature survey based on Nordic literature deals with the biology, use, harvesting and economy of birch (Betula sp.). According to the results, the easily quantified hard facts are against cultivation of birch: lower growth, poorer production of valuable assortments, lower price of pulp, higher planting costs, and higher harvesting and transport costs than for conifers. The soft facts, which may be true, are not easily measured or their importance evaluated: the possible improvement of soil, decreasing risk of insect and fungi attacks, shelter against frost etc. Due to the differences in the nature of the facts the discussion of cultivation of birch will probably continue.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5202, category Article
Kari Löyttyniemi. (1983). Flight periods of some birch timber insects. Silva Fennica vol. 17 no. 4 article id 5202. https://doi.org/10.14214/sf.a15185
Keywords: birch; Betula; insect damages; swarming; birch timber; Scolytus ratzeburgi; Agrilus viridis; Xiphydria camelus; Leptura quadrifasciata
Abstract | View details | Full text in PDF | Author Info

Flight periods of insects breeding on birch (Betula sp.) timber were observed by means of window flight traps baited with freshly cut birch logs in five locations in Finland from 1972 to 1976. Only few species were caught during the study. In general, these species were on the wing during midsummer, although flight periods of some of them were relatively long. Scolytus ratzeburgi Jans. caused harmful staining of wood within a month from attack, but the damage by the wood-boring pests remained negligible throughout the first storage summer.

The PDF includes a summary in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 5197, category Article
Kari Heliövaara, Erkki Annila, Eero Terho. (1983). Effect of nitrogen fertilization and insecticides on the population density of pine bark bug, Aradus cinnamomeus (Heteroptera, Aradidae). Silva Fennica vol. 17 no. 4 article id 5197. https://doi.org/10.14214/sf.a15180
Keywords: Pinus sylvestris; fertilization; Scots pine; height growth; insecticides; insect damages; prevention; nitrogen fertilization; Aradus cinnamomeus
Abstract | View details | Full text in PDF | Author Info

The effect of nitrogen fertilization and two insecticides on the occurrence of the plant pine bark bug, Aradus cinnamomeus Panzer, was investigated in a young Scots pine (Pinus sylvestris L.) stand in Southern Finland. Three years after the treatment the bug density was lowest in the trees treated with lindane or dimethoate. However, in spite of the increasing height growth of the trees, they did not grow significantly faster than the control trees. Nitrogen fertilization increased both bug density and the height growth of the trees. Thus, the value of nitrogen fertilization against Aradus cinnamomeus remains obscure.

The PDF includes a summary in Finnish.

  • Heliövaara, E-mail: kh@mm.unknown (email)
  • Annila, E-mail: ea@mm.unknown
  • Terho, E-mail: et@mm.unknown
article id 5195, category Article
Matti Rousi. (1983). Susceptibility of pine to mammalian herbivores in northern Finland. Silva Fennica vol. 17 no. 4 article id 5195. https://doi.org/10.14214/sf.a15178
Keywords: Pinus sylvestris; fertilization; Scots pine; Alces alces; moose; forest damage; seedling damages; arctic hare; Lepus timidus; root vole; Microtus oeconomus; bank vole; Microtus agrestis
Abstract | View details | Full text in PDF | Author Info

An inventory of Scots pine (Pinus sylvestris L.) graft collection in Kolari (67°15’ N, 23°45’ S) showed that severe damage by arctic hare (Lepus timidus L.), root and bank vole (Microtus oeconomus Pallas and M. agrestis L.) and moose (Alces alces L.) was done to grafts in size and in rather poor condition. Furthermore, the damage by arctic hare was dependent on the dry matter content of the needles. Another inventory in a fertilization experiment in a pine pole-stage forest showed that nitrogen fertilization increased the damage by arctic hare. On the basis of the present results, an assumption was made that the formation of repellent substances against herbivorous mammals is connected with wintering process of northern pines.

The PDF includes a summary in Finnish.

  • Rousi, E-mail: mr@mm.unknown (email)
article id 5191, category Article
Juha Lappi. (1983). Metsänuudistamisen vaatiman ajan merkitys uudistamispäätöksissä. Silva Fennica vol. 17 no. 3 article id 5191. https://doi.org/10.14214/sf.a15174
English title: Elevation of the time factor in reforestation decisions.
Original keywords: metsänuudistaminen; metsäsuunnittelu; kustannukset; uudistamisen viivästyminen; uudistumisaika; normaalimetsälaskelma; nollakorkomenetelmä; päätehakkuuikä; nykyarvomenetelmä
English keywords: forest planning; net present value; forest regeneration; cost of time delay; regeneration costs; final cutting age; regeneration method; zero percent interest rate
Abstract | View details | Full text in PDF | Author Info

Length of the regeneration period is a criterion commonly used for comparing different reforestation methods. The time factor should be evaluated using a realistic system for long-term planning. In this paper the preliminary evaluation is made by simplified calculations based on the development series. The slow regeneration method is assumed to be otherwise equal to the rapid one but it has a 5- or 10-years delay at the beginning, and the rotation is thus the final cutting age plus 5- or 10-years delay. Cost of the time delay is taken to be the difference in reforestation costs that makes the rapid and the slow methods equivalent. Calculations are made using zero costs for the slow method; but if the cost of the slow method increases, the critical cost difference decreases very slowly. The final cutting age and the regeneration method must be decided simultaneously. Therefore, the cost of the time delay is presented as a function of final cutting age. By maximizing the average annual revenue, rotation can be even increased if more rapid but more expensive regeneration method is used.

The PDF includes a summary in English.

  • Lappi, E-mail: jl@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 5168, category Article
Kari Heliövaara. (1982). The pine bark bug, Aradus cinnamomeus (Heteroptera, Aradidae) and the height growth rate of young Scots pines. Silva Fennica vol. 16 no. 4 article id 5168. https://doi.org/10.14214/sf.a15083
Keywords: Pinus sylvestris; Scots pine; height growth; insect damages; Aradus cinnamomeus
Abstract | View details | Full text in PDF | Author Info

Relationships between densities of pine bark bug, Aradus cinnamomeus Panzer and the height growth of young Scots pine (Pinus sylvestris L.) were studied in several habitats, including a highly infested area in Southern Finland. The slower the growth of the pines was, the greater was the height up to which bugs were found. On the average, maximum bug density was noted at a height corresponding to a fifth of the height of the tree. In stands restocked by natural generation, the greatest bug densities were noted in pines about three metres high and over twenty years old. Bug densities in trees whose height growth had been decelerating for five years were twice those in trees whose growth was accelerating. A significant negative correlation was found between the bug density and the last-year height increment.

The PDF includes a summary in Finnish.

  • Heliövaara, E-mail: kh@mm.unknown (email)
article id 5161, category Article
Juhani Päivänen. (1982). Physical properties of peat samples in relation to shrinkage upon drying. Silva Fennica vol. 16 no. 3 article id 5161. https://doi.org/10.14214/sf.a15076
Keywords: peat; density; bulk density; shrinkage; chemicophysical properties; drying; peat type
Abstract | View details | Full text in PDF | Author Info

The study discusses the amount of shrinkage of volumetric undisturbed peat samples when drying to an oven-dry (105°C) condition. The amount of shrinkage is related to various physical properties of peat. In addition, some observations were performed on the shrinkage phenomenon during the drying process. The study results may be used when predicting the shrinkage of peat samples with various peat properties. Knowledge of this kind is particularly important in connection with peat harvesting.

The PDF includes a summary in Finnish.

  • Päivänen, E-mail: jp@mm.unknown (email)
article id 5160, category Article
P. M. A. Tigerstedt. (1982). Metsäpuiden populaatiogenetiikka. Helsingissä 1981 pidetyn symposion tutkimusraportit. Silva Fennica vol. 16 no. 2 article id 5160. https://doi.org/10.14214/sf.a15075
English title: Population genetics of forest trees.
Original keywords: metsäntutkimus; metsänjalostus; kokoukset; siemenviljelmät; metsägenetiikka; populaatiogenetiikka; populaatiorakenne; sopeutuminen ympäristöolosuhteisiin; ekologinen erilaistuminen
English keywords: adaptation; seed orchards; population structure; population genetics; forest research; forest tree breeding; forest genetics; conference; ecological variation
Abstract | View details | Full text in PDF | Author Info

The publication comprises proceedings of a conference held in Helsinki in 1981. Forest tree populations are investigated for population genetic structure, mating systems, mechanisms of genetic adaptation and ecological adaptation. Methods and techniques used in population genetic research of forest trees are presented. Much concern is given to applications by means of forest tree breeding, particularly the seed orchard breeding technique. Generally, the application of population genetics in cultivated forests is discussed.

The PDF includes a preface and the presentations of the conference (25 short papers) in English, and a comprehensive summary of the themes of the conference in Finnish.

  • Tigerstedt, E-mail:
article id 5146, category Article
J. N. Cape, D. Fowler. (1981). Changes in epicuticular wax of Pinus sylvestris exposed to polluted air. Silva Fennica vol. 15 no. 4 article id 5146. https://doi.org/10.14214/sf.a15373
Keywords: Pinus sylvestris; needles; Scots pine; damage; air pollution; environmental impact; sulphur dioxide; foliage; epicuticular vax; cuticular transpiration
Abstract | View details | Full text in PDF | Author Info

Scanning Electron Microscopy was used to study structural changes in epicuticular vax of Pinus sylvestris L. with time. Changes in the contact angle of water droplets and in cuticular transpiration were also measured. By using material from a polluted and an unpolluted site it was shown that the ageing process occurs faster on polluted air, leading to greater cuticular transpiration and smaller contact angles at polluted sites.

  • Cape, E-mail: jc@mm.unknown (email)
  • Fowler, E-mail: df@mm.unknown
article id 5144, category Article
Lennart Folkeson. (1981). Impact of air-borne copper and zinc pollution on lichen and bryophyte vegetation near a brass foundry. Silva Fennica vol. 15 no. 4 article id 5144. https://doi.org/10.14214/sf.a15371
Keywords: bryophytes; lichen; damage; copper; coniferous forests; Hylocomnium splendens; mosses; air pollution; environmental impact; brass foundry; Hypogymnia physodes; zinc
Abstract | View details | Full text in PDF | Author Info

Air-borne Cu and Zn from a brass foundry at Gusum, SE Sweden, have considerably disturbed the lichen and bryophyte vegetation in the coniferous forest environment. The occurrence of lichens on Norway spruce twigs decreased rapidly with increasing Cu concentrations in Hypogymnia physodes above 90 ppm (background value 10–15). The epiphytic vegetation is reduced within 2–3 km from the foundry. Only stunted individuals occur in the close vicinity of the pollution source.

The cover of one of the quantitatively most important mosses, Hylocomnium splendens, is greatly reduced by the heavy-metal deposition. Cover values of 20–50% are not uncommon in distant sites (Cu concentration 15–35 ppm). There is a significant negative correlation between Cu concentration in the moss and its cover. The moss cannot survive much more than ca. 130 ppm Cu (and 360 ppm Zn). Live individuals are no more found within 1.5 km from the foundry.

  • Folkeson, E-mail: lf@mm.unknown (email)
article id 5141, category Article
Lisbeth Mortensen, Knud V. Weisberg. (1981). A method for measurement of actue leaf injury on tobacco indicator plants. Silva Fennica vol. 15 no. 4 article id 5141. https://doi.org/10.14214/sf.a15368
Keywords: damages; photography; measuring methods; air pollution; bioindicators; Nicotiana tabacum; leaves; damaged leaf area; ozone
Abstract | View details | Full text in PDF | Author Info

A technique for instrumental scoring of damaged leaves on tobacco (Nicotiana tabacum) indicator plants caused by ozone in the lower atmosphere is being developed. The leaves are photographed in situ with an integrated unit, which illuminates the leaf from behind and keeps the camera in a well-defined position. By using microfilm and a minus green filter, it is possible to obtain negatives where the necrotic flecks appear as dark spots on a white leaf. The negatives are scanned in a TV-system and the size of the damaged fraction of the leaf is calculated by a microprosessor and is shown as a percentage of the leaf.

  • Mortensen, E-mail: lm@mm.unknown (email)
  • Weisberg, E-mail: kw@mm.unknown
article id 5124, category Article
Leo Heikurainen, Samuli Joensuu. (1981). Metsäojituksen hydrologiset seurausvaikutukset. Silva Fennica vol. 15 no. 3 article id 5124. https://doi.org/10.14214/sf.a15065
English title: The hydrological effects of forest drainage.
Original keywords: ojitus; ojitetut suot; hydrologia; vesistövaikutukset
English keywords: drained peatlands; water quality; drainage; hydrology; discharge
Abstract | View details | Full text in PDF | Author Info

The present paper deals with the most important factors of peatland hydrology and the influence of forest drainage on the hydrology of peatland itself and its surroundings. It is compiled of six seminar papers written by students in the Department of Peatland Forestry in the University of Helsinki. Special attention is paid to the hydrological consequenses of the maintenance of drained areas. Also ways and measures to minimize the negative environmental effects of these treatments are discusses.

The PDF includes a summary in English.

  • Heikurainen, E-mail: lh@mm.unknown (email)
  • Joensuu, E-mail: sj@mm.unknown
article id 5123, category Article
Heljä-Sisko Katainen, Seppo Kellomäki. (1981). Happaman veden vaikutus männyn taimiin. Silva Fennica vol. 15 no. 3 article id 5123. https://doi.org/10.14214/sf.a15064
English title: Effect of foliar application of dilute sulphuric acid on Scots pine seedlings.
Original keywords: mänty; taimet; pituuskasvu; neulasvauriot; fotosynteesi; happamuus; hapan sade
English keywords: Pinus sylvestris; photosynthesis; Scots pine; height growth; acidity; seedlings; needle damages; acid rain
Abstract | View details | Full text in PDF | Author Info

Needle damages, transpiration, photosynthesis and needle and stem height growth of Scots pine (Pinus sylvestris L.) seedlings treated with dilute sulphuric acid were studied. The acidity of the solution was pH 3. Application of a dilute solution of sulphuric acid equivalent to the normal amount of precipitation occurring during the growing season damaged the surface of two-year-old needles but not that of the current-year needles. A reduction in the photosynthetic rate of 10–30% was observed compared with the untreated seedlings. Transpiration of the seedlings was not affected by the treatment. Needle growth and stem height growth of the seedlings growing on a substrate representing poor sandy soil were reduced. Increased needle growth and stem height growth were characteristic for the seedlings growing on substrate representing fertile moraine.

The PDF includes a summary in English.

  • Katainen, E-mail: hk@mm.unknown (email)
  • Kellomäki, E-mail: sk@mm.unknown
article id 5121, category Article
Olli Makkonen. (1981). Metsätöiden palkkauksen ja työolosuhteiden kehitys Suomessa ennen työehtosopimuskautta. Silva Fennica vol. 15 no. 3 article id 5121. https://doi.org/10.14214/sf.a15062
English title: Development of the wages and work conditions in forest work in Finland prior to the age of agreements on the terms of working.
Original keywords: historia; uitto; metsätyö; palkkaus; työolot; asumisolot
English keywords: Finland; history; floating; forest work; wages; working conditions; lodging
Abstract | View details | Full text in PDF | Author Info

In Finland the first trade union in the field of forest work and timber floating was founded in 1946 and the first formal collective agreement was achieved in 1962. Information about the development of wage payments and work conditions (lodging and food) in forest work prior to the formal agreements was dispersed in a number of different sources, and is already partially in danger of being forgotten. The aim of this study was to bring together all available information concerning the matter in question.

The PDF includes a summary in English.

  • Makkonen, E-mail: om@mm.unknown (email)
article id 5110, category Article
Helena Lehtiö. (1981). Effect of air pollution on the volatile oil in needles of Scots pine (Pinus sylvestris L.). Silva Fennica vol. 15 no. 2 article id 5110. https://doi.org/10.14214/sf.a15051
Keywords: Pinus sylvestris; needles; Scots pine; needle damages; air pollution; monoterpene composition; volatile oil
Abstract | View details | Full text in PDF | Author Info

The amount of volatile oil and monoterpene composition in Scots pine (Pinus sylvestris L.) needles were studied in trees growing near two factories and in the city of Kuopio, Central Finland. Trees in these locations are exposed principally to sulphur dioxide and fluoride emissions.

The amount of volatile oil increased with increasing injury class in the trees growing near the fertilizer factory. The amounts of volatile oil in trees near the pulp mill differed in the various injury classes. More oil was found in younger needles. The greatest differences in monoterpene composition were in the amounts of camphene, α-pinene, myrcene and tricyclene.

The PDF includes a summary in Finnish.

  • Lehtiö, E-mail: hl@mm.unknown (email)
article id 5106, category Article
Päiviö Riihinen. (1981). Effectiveness of forest taxation reform as a means of economic policy. Silva Fennica vol. 15 no. 1 article id 5106. https://doi.org/10.14214/sf.a15047
Keywords: forest policy; forest taxation; private forests; small-scale forestry; stumpage revenues; area-based yield
Abstract | View details | Full text in PDF | Author Info

In dealing with the effectiveness of forest taxation reform as a means of economic policy, the paper starts by recalling certain objectives of taxation, as well as the effect on aggregate demand of taxation in general. The effect of forest taxation depends on such factors as (1) whether the woodland owner has a regular income from a source other than forestry; (2) the system of taxation (whether taxation of actual stumpage revenue or of area-based yield); (3) the progression of taxation; and (4) the woodland owner’s income level.

The problem is illustrated by an example taken from Finland, where forestry revenue is taxed on the basis of area-based yield. A shift to taxation of actual stumpage revenue, as is proposed, is assumed. The effectiveness of this change is studied in terms of how far the assumed change is consistent with the objectives of the national economy. It is assumed that a shift to taxation of actual stumpage revenue would cause a decline in roundwood supply. A sensitivity analysis is then applied to detect the effect on tax revenue and national income of the tax reform. It is likely that a 10% decrease in fellings would bring about a reduction of tax revenue which would not be compensated for by the more perfect exposure of forestry income to taxation brought by the reform. The effect on investment, production, employment, differences in individual and regional income, and on the international balance of payments also disfavour the suggested change.

  • Riihinen, E-mail: pr@mm.unknown (email)
article id 5105, category Article
John Eid. (1981). Forest as a capital asset. Silva Fennica vol. 15 no. 1 article id 5105. https://doi.org/10.14214/sf.a15046
Keywords: forestry; profitability; small-scale forestry; capital management; capital investments
Abstract | View details | Full text in PDF | Author Info

The paper discusses certain aspects of the capital management of forest assets. These aspects are of importance when one wants to consider what means to use to influence the capital management on both small and big forest properties. When quantifying the effects of different uses of capital, one must necessarily have a scale. The rate of return is for this purpose the usual measure of profitability. We will first discuss the differences between nominal and real rate of return, and point out the assumptions which are often implicit in analyses of the profitability of investments in forestry. We will the discuss certain liquidity and risk aspects of capital investments in forestry, and at the end deal with certain consequences of taxation.

  • Eid, E-mail: je@mm.unknown (email)
article id 5093, category Article
Ismo Karhu, Seppo Kellomäki. (1980). Väestön mielipiteet metsänhoidon vaikutuksesta maisemakuvaan Puolangan kunnassa. Silva Fennica vol. 14 no. 4 article id 5093. https://doi.org/10.14214/sf.a15034
English title: Effects of silvicultural practises on the forest landscape. A study on attitudes among inhabitants of Puolanka, north-eastern Finland.
Original keywords: metsänhoito; mielipidetutkimus; metsien virkistyskäyttö; metsämaisema; maiseman arvostus; Puolanka
English keywords: forest management; Finland; recreation; forest landscape; scenic values; attractiveness
Abstract | View details | Full text in PDF | Author Info

The landscape preferences and attitudes of inhabitants of Puolanka, north-eastern Finland, to the effects of silvicultural practice on the forest landscape were studied by a postal inquiry. The effect of silvicultural practice on the forest landscape was mainly negative. Birch (Betula sp.) stands and mixed coniferous and deciduous tree species were the most preferred by the Puolanka inhabitants. The landscape preferences were related to socio-economic background of the inhabitants. The quality of the living environment also influenced the preferences, since uncommon features in the living environment were favoured most.

The PDF includes a summary in English.

  • Karhu, E-mail: ik@mm.unknown (email)
  • Kellomäki, E-mail: sk@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 5089, category Article
Seppo Kellomäki. (1980). Alustavia mittaustuloksia kuivauksen ja liotuksen vaikutuksesta kuorellisen mänty- ja kuusipuutavaran kuoren paksuuteen. Silva Fennica vol. 14 no. 4 article id 5089. https://doi.org/10.14214/sf.a15030
English title: Preliminary results of the effect of drying and soaking of the bark thickness of Scots pine and Norway spruce.
Original keywords: kuusi; puutavara; mänty; varastointi; kuori; runkopuu; paksuusmuutos; kuivuminen; liotus
English keywords: Norway spruce; Scots pine; storage; bark thickness; timber; dimensions; dryining; soaking
Abstract | View details | Full text in PDF | Author Info

On the basis of a limited material, the drying of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) timber at room temperature decreased the thickness of the bark proportionally to the decrease in the moisture content. The decrease was the greatest in the middle portion of the trunk. In the spruce material, the decrease in bark thickness was exceeded by the shrinkage of the wood. During soaking, the bark thickness of both tree species decreased, too, contrary to the presupposed hypothesis. In both cases, the shrinkage was the greatest in the middle portion of the trunk. In the spruce material, the decrease in bark thickness was exceeded by the shrinkage of the wood. Possible explanation for the phenomenon is discussed.

The PDF includes a summary in English.

  • Kellomäki, E-mail: sk@mm.unknown (email)
article id 5088, category Article
Reijo Solantie, Kari Ahti. (1980). Säätekijöiden vaikutus Etelä-Suomen lumituhoihin v. 1959. Silva Fennica vol. 14 no. 4 article id 5088. https://doi.org/10.14214/sf.a15029
English title: The influence of weather on the snow damages for forests in Southern Finland in 1959.
Original keywords: Etelä-Suomi; lumituhot; sääolosuhteet; sääilmiöt; huurre
English keywords: snow damage; rime; weather conditions; Southern Finland; orographic precipitation
Abstract | View details | Full text in PDF | Author Info

Snow and rime, attached to branches of conifers, seriously damaged forests in a region of 11,000 km2 in Southern Finland during a passage of two nearly occluded cyclones in 1959. The roles of different weather elements were studied by considering the variations occurring in them over this region and its surroundings. Damage occurred only inside an accentuated pattern of copious orographic precipitation. Precipitation only became attached to and retained on branches in such parts of the area where temperature varied on both sides of freezing point but did not exceed 0.6°C. Furthermore, damage only occurred in forests where rime formed (above a certain level and on sloping towards the prevailing wind).

The PDF includes a summary in English.

  • Solantie, E-mail: rs@mm.unknown (email)
  • Ahti, E-mail: ka@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 5074, category Article
Jukka Selander, Matti Nuorteva. (1980). Feromonivalmisteen käyttö kirjanpainajien torjumiseksi kuolevassa kuusikossa. Silva Fennica vol. 14 no. 2 article id 5074. https://doi.org/10.14214/sf.a15015
English title: Use of synthetic pheromones for the control of spruce bark beetle in a heavily infested Norway spruce stand.
Original keywords: kuusi; kaarnakuoriaiset; torjunta; hyönteistuho; kirjanpainaja; feromonit
English keywords: bark beetles; insect damages; prevention; Ips typographus; Ips duplicatus; pheromones
Abstract | View details | Full text in PDF | Author Info

The dying-off of more trees in an over-aged Norway spruce (Picea abies (L.) H. Karst.) stand caused by Ips-bark beetles was reduced by a pheromone preparation, ipslure. 20 preparations placed in trapping bolts captured more than 13,700 specimens of Ips typographus L. and Ips duplicatus Sahlb., which alone corresponded to a saving of five old trees in this valuable exhibition and seed collection stand. Attractance of ipslure to the following predators of bark beetles was also examined; Thanasimus formicarius, T. rufipes, Epuracea bickhardti, Rhizophagus ferrugineus, Pityophagus ferrugineus.

The PDF includes a summary in English.

  • Selander, E-mail: js@mm.unknown (email)
  • Nuorteva, E-mail: mn@mm.unknown
article id 5071, category Article
Martti Ryynänen. (1980). X-ray radiography of ageing Scots pine seeds. Silva Fennica vol. 14 no. 1 article id 5071. https://doi.org/10.14214/sf.a15012
Keywords: Pinus sylvestris; germination; Scots pine; storage; seeds; quality of seeds; X-ray radiography; X-ray contrast radiography
Abstract | View details | Full text in PDF | Author Info

Soft X-ray radiation (Grenz rays) has been used in the X-ray radiography of seeds. It is based on the principle that the different parts of the seed absorb X-rays to a slightly varying extent. Empty seeds and empty regions in the seeds appears as dark areas on the film. X-ray radiography without staining and X-ray contrast radiography were compared to study the stored seeds of Scots pine (Pinus sylvestris L.). The results were compared with the results of germination in a Jacobsen germinator according to ISTA norms.

Normal X-ray radiography gave too good estimates of germinative capacity of the seeds, and was shown to suit only when it is used to study fully ripe seeds which have recently been collected in an undamaged condition. The results of X-ray contrast radiography when barium chloride was used as the stain, however, followed closely the germination results.

The PDF includes a summary in Finnish.

  • Ryynänen, E-mail: mr@mm.unknown (email)
article id 5044, category Article
Kullervo Kuusela. (1979). Forest balance on the national level. Silva Fennica vol. 13 no. 3 article id 5044. https://doi.org/10.14214/sf.a14901
Keywords: forestry; forest management planning; forest balance; utilization of forests
Abstract | View details | Full text in PDF | Author Info

Forest balance is a comparison between the growing stock volume at the beginning and end of a balance period and the gross increment and drain during that period. The forest balance of Finland during that period 1967-1973 and the increment and drain balance during the period 1953-1977 are used as examples in the paper. Forest balance is a check of the accuracy of basic estimates. If the discrepancy between the calculated growing stock at the end of the balance period and the growing stock estimated by an inventory is great, it calls for improvements in forest inventory methods and timber utilization statistics.

Balance may reveal possibilities for improving the utilization of forest resources. If natural losses are great, increased thinnings and regeneration cuttings of mature and over-mature tree stands increase the supply of timber. If logging losses are great, the efficiency of harvesting should be improved. An overcutting situation calls forth efforts to increase timber production or to decrease the uses of timber in order to avoid overexploitation. If gross increment is greater than the drain there are possibilities to increase harvesting, forest industrial expansion etc.

Forest balance is a way to check and improve the basic estimates of forestry production, to increase the effective use of timber grown in the forest, to commerce policies and measures concerning increment and to control timber utilization on the basis of sustained yield.

The PDF includes a summary in Finnish.

  • Kuusela, E-mail: kk@mm.unknown (email)
article id 5022, category Article
Jukka Selander, Paavo Kalo. (1979). Männyn taimen pihkan monoterpeenien vaikutuksista tuhonkestävyyteen tukkimiehentäitä, Hylobius abietis L. ( Coleoptera, Curculionidae) vastaan. Silva Fennica vol. 13 no. 2 article id 5022. https://doi.org/10.14214/sf.a14876
English title: Evaluation of resistance of Scots pine seedlings against the large pine weevil Hylobius abietis L. in relation to their monoterpene composition.
Original keywords: hyönteistuhot; mänty; taimet; tukkimiehentäi; resistenssi; monoterpeeni
English keywords: Pinus sylvestris; Scots pine; Hylobius abietis; seedlings; insect damages; large pine weevil; monoterpenes; insect resistance
Abstract | View details | Full text in PDF | Author Info

The development of Scots pine (Pinus sylvestris L.) seedlings and damage caused by Hylobius abietis L. (Coleoptera, Curculionidae) were studied during a three-year period. Olfactory responses of H. abietis was studied in laboratory with several volatile oils isolated from different kinds of P. sylvestris seedlings. Resistance of seedlings against H. Abietis was evaluated in terms of their monoterpene composition. Three aspects of resistance (preference, antibiosis and tolerance) were evaluated separately. Seedling chemotype was found to be associated with these aspects of host resistance on only minor scale. Discussion was attached to a further search for host resistance arising from other properties and constituents of oleoresin. Height growth of the seedlings recovering from weevil damage was 86–91% compared to healthy seedlings.

The PDF includes a summary in English.

  • Selander, E-mail: js@mm.unknown (email)
  • Kalo, E-mail: pk@mm.unknown
article id 5013, category Article
Matti Leikola. (1979). Tutkimustoiminta Lapin metsien hoidon ja käytön suuntaajana. Silva Fennica vol. 13 no. 1A article id 5013. https://doi.org/10.14214/sf.a14867
English title: The role of forestry in guiding forest policy and management in Finnish Lapland.
Original keywords: metsäntutkimus; metsänhoito; metsätalous; historia; Lappi
English keywords: forest management; forest policy; forestry; Finland; Lapland; history; forestry research
Abstract | View details | Full text in PDF | Author Info

The part played by research work in guiding the management and utilization of Lapland’s forests is examined in this publication. The review has been written to mark the 70th anniversary of the Finnish Forestry Society (now the Finnish Society of Forest Science).

The climate in Lapland is very severe and, owing to the lack of experience abroad, forestry has been forced to follow the guidelines set by domestic research activity in Finland. Research work was very active in Lapland the 1910’s, 1920’s and 1950’s, and the main outlines for forestry utilisation were soon established. In the 1950’s, there was a strong trend prevailing to develop forestry, with the result that a change took place in favour of clear-cutting. The cool climate period in the 1960’s caused considerable damage to young plantations. In order to find means to rectifying the situation and to devise new guidelines for forest management, The Finnish Forest Research Institute established a number of research stations in Lapland.

Research activity has had a pronounced effect on the management and utilization of forests in Lapland. Present-day problems have been caused more by the international situation than by difficulties in the management of forests in Lapland.

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  • Leikola, E-mail:
article id 5003, category Article
Hannu Saarenmaa. (1978). The occurrence of bark beetles (Col., Scolytidae) in a dead spruce stand flooded by beavers (Castor canadensis Kuhl.) . Silva Fennica vol. 12 no. 3 article id 5003. https://doi.org/10.14214/sf.a14857
Original keywords: kuusi; hyönteistuhot; tulva-alueet; kaarnakuoriaiset; kanadanmajava
English keywords: bark beetles; Norway spruce; Picea abies; Castor canadensis; insect damages; Trypodendron lineatum; flooded areas; Pityogenes chalcographus; Hylurgops palliatus; Ips typographus; Dryocetes autographus
Abstract | View details | Full text in PDF | Author Info

 

The aim of the study was to determine which kinds of insects had infected the Norway spruce (Picea abies (L.) H. Karst.) in different stands killed by flooding caused by beavers (Castor canadensis Kuhl), and if there was any danger that they would subsequently cause damage in the surrounding forests. The effect of tree diameter and certain stand characteristics on the fauna of dead trees are discussed. The occurrence of different insect combinations and qualifications for their coexistence were studied.

Pityogenes chalcographus L., Trypodendron lineatum O., Hylurgops palliatus Gyll. and Dryocetes autographus Ratz. occurred most abundantly. 20 phloem or wood boring species were observed in 5 regular succession types. Secondary species occurred in a virgin stand while Ips typographus L. was found at the edge of a felling area. Owing to the flooding, species preferring moist conditions were abundant. In this case damages had not spread to the surrounding forests which, however, might be possible under certain conditions.

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  • Saarenmaa, E-mail: hs@mm.unknown (email)
article id 5001, category Article
Seppo Kellomäki. (1978). Recreational potential of a forest stand. Silva Fennica vol. 12 no. 3 article id 5001. https://doi.org/10.14214/sf.a14855
Keywords: developmental stage; ground vegetation; stand volume; trampling tolerance; reacreation
Abstract | View details | Full text in PDF | Author Info

The aim of the paper was to investigate the recreational potential of successional stand based on the suitability of the stands for different recreational activities and the trampling tolerance of ground cover. The relationship between selected recreational activities and the volume of the stands under study has been determined. These functions have been utilized in determining the potential of the successional stand for different recreational activities. Combining this information with trampling tolerance gave criteria for determining the recreational potential of a stand. The results emphasize the importance of varying the distribution of development stages in a recreational area and in its management.

The PDF includes a summary in Finnish.

  • Kellomäki, E-mail: sk@mm.unknown (email)
article id 4992, category Article
Kari Löyttyniemi, Raimo Hiltunen. (1978). Monoterpenes in Scots pine in relation to browsing preference by moose (Alces alces L.). Silva Fennica vol. 12 no. 2 article id 4992. https://doi.org/10.14214/sf.a14846
Keywords: Pinus sylvestris; Scots pine; Alces alces; moose; moose damages; monoterpenes
Abstract | View details | Full text in PDF | Author Info

Monoterpene hydrocarbon contents of needles in Scots pine (Pinus sylvestris L.) plants both damaged and untouched by the moose (Alces alces L.) were compared in the study. The material was collected in an 8-year-old plantation in Central Finland. Needle samples were taken from the topmost shoot whorl of the plants in the middle of April, 1976. Only minor differences were found between the plant groups. Thus, terpenes in pine presumably play no important role in the browsing preference by moose.

The PDF includes a summary in Finnish.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
  • Hiltunen, E-mail: rh@mm.unknown
article id 4984, category Article
Jyrki Raulo. (1978). Forestation chain for birch (Betula pendula Roth) in Finland. Silva Fennica vol. 12 no. 1 article id 4984. https://doi.org/10.14214/sf.a14838
Keywords: forest management; Betula pendula; regeneration; silver birch; Finland
Abstract | View details | Full text in PDF | Author Info

During the 1970’s an average of 4 million Betula pendula (Roth) seedlings have been planted annually in Finland. The activities connected with the planting of this tree species, the selection of forestation sites, site preparation, planting out the seedlings and follow-up work on the forestation sites are briefly reviewed in the article. The manuscript is based on the studies into the breeding, seedling production and planting techniques of B. pendula started by the Finnish Forest Research Institute already in 1960’s, as well as on practical observations made at the planting sites. A list of some of the Finnish studies concerning B. pendula which have been published in English and studies with a summary in English is included.

The PDF includes a summary in Finnish.

  • Raulo, E-mail: jr@mm.unknown (email)
article id 4982, category Article
Olli Järvinen, Kullervo Kuusela, Risto A. Väisänen. (1977). Metsien rakenteen muutoksen vaikutus pesimälinnustoomme viimeisten 30 vuoden aikana. Silva Fennica vol. 11 no. 4 article id 4982. https://doi.org/10.14214/sf.a14836
English title: Effects of modern forestry on the numbers of breeding birds in Finland.
Original keywords: metsänhoito; metsätalous; linnusto; lintulajit; luonnonmetsät
English keywords: forest management; natural forests; bird populations; commercial forestry
Abstract | View details | Full text in PDF | Author Info

Pair numbers of breeding land birds were estimated from line transects data collected in Finland in 1936–76. The changes observed in the bird populations are in this paper compared with data obtained in the Finnish forest inventories, particularly made in 1951–53 and 1971–76. It is concluded that modern forestry has considerable impact on the breeding bird fauna. In general, more species have increased than decreased due to changes in the forests. Areas affected by forestry are more favourable habitats for many species than natural forests, but, on the other hand, there are certain species which are greatly harmed by the effects of modern forestry.

The PDF includes a summary in English.

  • Järvinen, E-mail: oj@mm.unknown (email)
  • Kuusela, E-mail: kk@mm.unknown
  • Väisänen, E-mail: rv@mm.unknown
article id 4961, category Article
Helmut Schmidt-Vogt. (1977). Keski-Euroopan metsänhoidon kehityssuuntia. Silva Fennica vol. 11 no. 1 article id 4961. https://doi.org/10.14214/sf.a14812
English title: Trends in the forest management in Central Europe.
Original keywords: metsänkäyttö; metsänhoito; virkistyskäyttö; metsien monikäyttö; Keski-Eurooppa; ympäristönsuojelu
English keywords: forest management; forestry; forest management planning; forest utilization; recreation; Germany; Central Europe; Bavaria; environmental management
Abstract | View details | Full text in PDF | Author Info

In the densely populated Central Europe, forestry has always had different functions than in Scandinavia or Canada. Today the increasing pressures on the environment and more numerous demands of the people have put emphasis on environmental management and the demands of recreation in forest management practiced in the area. This paper outlines the trends in the utilization of forests in Central Europe, and especially in the Federal Republic of Germany, due to these changing targets. The regulations concerning forestry in Baden-Würtenber, and the forest plan of the Bavarian state forests are used as an example to clarify the principals of forest management and planning.

  • Schmidt-Vogt, E-mail: hs@mm.unknown (email)
article id 4951, category Article
Heikki Heiskanen. (1976). Metsätyön palkkauksen perusongelmat. Silva Fennica vol. 10 no. 4 article id 4951. https://doi.org/10.14214/sf.a14797
English title: Basic problems of the wage system for forest work.
Original keywords: metsätyö; palkkaus; urakkapalkka; aikapalkka; ikääntyvät työntekijät
English keywords: forest work; wages; piece rate; time rate; aging workers
Abstract | View details | Full text in PDF | Author Info

It has been in Finland discussed to replace the present straight piece rate by a time rate in forest work. The low earnings of aged forest workers, the health hazards, its tendency to cause conflicts and considerable income differences are the main drawbacks of the piece rate and the proneness to increase the labour costs is the essential fault of the time rate mentioned in the discussion. One possible solution for these problems is an efficiency bonus (prevents the labour costs from increasing and decreases the income differences) combined with a bonus for age (guarantees high incomes for aged wage earners), a maximum efficiency standard (prevents health hazards), and a group incentive (prevents conflicts).

The PDF includes a summary in English.

  • Heiskanen, E-mail: hh@mm.unknown (email)
article id 4945, category Article
Olli Saastamoinen, Jan Heino. (1976). Metsien moninaiskäytön tutkimusaiheita. Silva Fennica vol. 10 no. 3 article id 4945. https://doi.org/10.14214/sf.a14791
English title: Research topics of multiple-use forestry.
Original keywords: metsäntutkimus; metsänhoito; metsien monikäyttö; metsien talouskäyttö
English keywords: forest management; forest research; multiple use of forests; commercial use of forests
Abstract | View details | Full text in PDF | Author Info

The purpose of this study was to gain an insight into research problems and themes in multiple use of forests from a practical viewpoint. An inquiry concerning multiple use problems was sent to 597 organizations whose work related to multiple use of forests. Replies yielded 1,857 suggested research themes which were divided between different uses of forests. About half of the suggestions concerned the relations between timber production and the other uses of forests. The many propositions are due to the fact that timber production in its intensity has strong influence on the other uses of forests. The results of the study have been used in the planning of research in the multiple use of forests.

The PDF includes a summary in English.

  • Saastamoinen, E-mail: os@mm.unknown (email)
  • Heino, E-mail: jh@mm.unknown
article id 4921, category Article
Simo Hannelius. (1975). Ojitusalueiden kulkukelpoisuudesta puunkorjuussa. Silva Fennica vol. 9 no. 3 article id 4921. https://doi.org/10.14214/sf.a14763
English title: On the trafficability of drained peatlands in harvesting.
Original keywords: puunkuljetus; harvennushakkuu; puunkorjuu; turvemaat; ojitetut suot; metsäkoneet; puustovauriot; kantavuus; routa; koneistuminen
English keywords: soil frost; drained peatlands; thinnings; mechanization; forest haulage; timber harvesting; forwarders; bearing capacity; logging conditions
Abstract | View details | Full text in PDF | Author Info

During the next decade there will be a marked increase in the allowable cut in drained peatlands. At the same time, the mechanization in logging proceeds, and in short-distance haulage the use of forwarders will increase. This study, based on literature and some observations, deals with logging conditions in drained peatlands with special reference to the suitability of heavy logging machines for use in such terrain. In addition, soil frost and the bearing capacity of the frozen peat soil were studied.

Freezing of the soil in a drained peatland area depends prevailingly on the weather conditions during early winter. The factors influencing soil freezing of a drained peatland are completely different from those regulating the freezing of natural peat soils. The frost penetrates in general deeper in the drained than virgin peatland. The topmost peat layer does not, however, freeze uniformly. Generally speaking, the bearing capacity of a drained peat soil is lower than that of undrained peat due to lower water content.

It is concluded that heavy logging machines are probably not fitted for use in drained areas on peatland even if the average soil frost values recorded would suggest it. Moreover, because of their extremely superficial root systems, peatland forests are exposed to damages by heavy machines in thinning operations.

The PDF includes a summary in English.

  • Hannelius, E-mail: sh@mm.unknown (email)
article id 4914, category Article
Antero Piha. (1975). Metsänhoitoyhdistyslain syntyvaiheet. Silva Fennica vol. 9 no. 1 article id 4914. https://doi.org/10.14214/sf.a14758
English title: The creation of the Act on Forest Owners’ Associations passed in 1950.
Original keywords: metsänhoito; historia; lainsäädäntö; metsänhoitoyhdistykset; yksityismetsänomistajat
English keywords: forest management; legislation; forest organizations; forest owners' associations; private forest owners
Abstract | View details | Full text in PDF | Author Info

The paper, which was written already at the turn of the year 1950–51, gives a quite detailed description of the early history of the Act on Forest Owners’ Associations, which was passed on 17 November 1950 and is still in force, of the long-lasting and multifarious preparations involved with it, and of its consideration in the parliament. In most parties there were both supporters and opponents; only the social democrats voted harmoniously for the act and the people’s democrats against it.

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  • Piha, E-mail: ap@mm.unknown (email)
article id 4912, category Article
Seppo Kellomäki. (1975). Havaintoja metsän aluskasvillisuuden biomassan ja peittävyyden välisestä suhteesta. Silva Fennica vol. 9 no. 1 article id 4912. https://doi.org/10.14214/sf.a14756
English title: Studies concerning the relationship between biomass and coverage in ground vegetation of a forest stand.
Original keywords: aluskasvillisuus; biomassa; peittävyys; kenttäkerros; puolukkatyyppi; kanervatyyppi
English keywords: biomass; ground vegetation; field layer; Calluna type; Vaccinium type; coverage
Abstract | View details | Full text in PDF | Author Info

The study deals with the relationship between biomass and coverage in ground vegetation of Vaccinium and Calluna forest types. The results show that the biomass of the field layer on both forest types can predict satisfactorily in both coverage values of some the most important species and groups of species. Their total height per plot was used as independent variables. The explaining power of the models constructed for Vaccinium type increased to approximately 57% and for the Calluna type to approximately 74% of the total variation in the amount of dry matter. When the biomass of the bottom layer was predicted using the same kind of variables, the explaining power for the Vaccinium type increased to approximately 35% of the total variation and for the Calluna type approximately 53% of the total variation in the amounts of dry matter. The models for field layer of both Vaccinium and Calluna types were quite well suited for describing the test material. In the case of the bottom layer, the constructed models were not suitable for describing the test material.

The PDF includes a summary in English.

  • Kellomäki, E-mail: sk@mm.unknown (email)
article id 4908, category Article
Juhani Päivänen. (1974). Sarkaleveyden ja naveroinnin vaikutus pohjavesipinnan syvyyteen ja männyntaimiston kehitykseen lyhytkortisella nevalla. Silva Fennica vol. 8 no. 4 article id 4908. https://doi.org/10.14214/sf.a14752
English title: The effect of ditch spacing and furrowing on depth of ground water table and on development of a Scots pine plantation on small-sedge bog.
Original keywords: mänty; ojitetut suot; avosuot; pituuskasvu; sarkaleveys; naverointi; kuivatussyvyys; kuivatusteho
English keywords: Pinus sylvestris; drained peatlands; Scots pine; height growth; seedlings; open peatlands; drainage effect; ground water table; ditch spacing; furrowing
Abstract | View details | Full text in PDF | Author Info

The paper describes the results obtained from an investigation into the effect of ditch spacing, ditch depth and furrowing on ground water table and on development of a Scots pine (Pinus sylvestris L.) plantation on open small-sedge bog in Central Finland (60° 50’ N; 24° 20’ E), drained in 1967. The area was planted in 1968 with 2+1 Scots pine transplants, and fertilized with Y fertilizer for peat soils. The seedlings were measured in 1972.

The depth of the ground water table was greater, the narrower the ditch spacing. The water furrows shortened the duration of the high ground water and lowered the ground water table particularly in the case of ineffective drainage. The narrower the ditch spacing within the blocks, the higher were the young trees. On the other hand, the differences in the height of the trees between the ditch spacings were eliminated by the effect of the furrows.

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  • Päivänen, E-mail: jp@mm.unknown (email)
article id 4906, category Article
Lasse Lovén. (1974). Maisemanhoitomallien käyttö metsätalouden maan aluevaraussuunnittelussa. Silva Fennica vol. 8 no. 3 article id 4906. https://doi.org/10.14214/sf.a14750
English title: Regional landscape planning of forest areas.
Original keywords: metsänhoito; metsänhoitajat; maisemanhoito; asennetutkimus; metsien monikäyttö; puuntuotanto; metsämaisema
English keywords: forest management; Finland; landscape planning; timber production; landscape management; multiple use of forests; forest landscape; attitude studies
Abstract | View details | Full text in PDF | Author Info

The study deals with economic significance of forest landscape planning models used in regional planning in Finland. The »judge»-method is used among professional foresters working on private forestry boards in Southern Finland to define their view of what would be moderate level of costs of landscape management for private forest owners. A sample of 154 forest professionals working in district forestry boards in Southern Finland was sent a sociological questionnaire.

It was possible to form three hierarchical moderation classes by statistical grouping of judgement distributions. Prolongations in rotation ages and restrictions concerning ditching of forested bogs, forest read building and clear-cutting were considered the most immoderate models. Rather or wholly insignificant were evaluated such management models, which mean restrictions in »old fashioned» methods or which are already used in practice.

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  • Lovén, E-mail: ll@mm.unknown (email)
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 4871, category Article
Kari Löyttyniemi. (1972). Hybridihaavikoiden hyönteistuhoista. Silva Fennica vol. 6 no. 3 article id 4871. https://doi.org/10.14214/sf.a14678
English title: Insect damages in hybrid aspen stands.
Original keywords: hyönteistuhot; hybridihaapa
English keywords: hybrid aspen; insect damages; Populus tremula x Populus tremuloides; Saperda populnea; Saperda carcharias; Chionaspis salicis; Populus x wettsteinii
Abstract | View details | Full text in PDF | Author Info

Hybrid aspen (Populus tremula L. x Populus tremuloides Michx.) has been grown in Finland for about 20 years, and the area of the stands is currently about 400 ha. Growing is planned to be greatly expanded to grow raw material for match industry. The aim of this investigation was to study susceptibility of hybrid aspen to insect damages. Insect damages in hybrid aspen, growing in Southern Finland, were examined in 15 stands in 1972. Saperda species were observed to be the most numerous and harmful insect species. Saperda carcharias L. occurred in 26% and Saperda populnea L. in 36% off trees inspected. Mass occurrence of Chionaspis salicis L. was observed in some sample areas.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4870, category Article
Matti Nuorteva. (1972). Tumamonisärmiöviruksen käytöstä ruskean mäntypistiäisen (Neodiprion sertifer Geoffr.) torjunnassa. Silva Fennica vol. 6 no. 3 article id 4870. https://doi.org/10.14214/sf.a14676
English title: Use of the nuclear polyhedrosis virus in the control of the European pine sawfly (Neodiprion sertifer Geoff.).
Original keywords: hyönteistuhot; mänty; tummamonisärmiövirus; ruskomäntypistiäinen; biologinen torjunta; virukset
English keywords: biological control; insect damage; polyhedrosis virus; Neodiprion sertifer; European pine sawfly; Borrelinavirus diprionis
Abstract | View details | Full text in PDF | Author Info

Experimental applications of the nuclear polyhedrosis virus (Borrelinavirus diprionis) to control of the European pine sawfly (Neodiprion sertifer Geoff.) was carried out during the last outbreak of this sawfly in in Scots pine (Pinus sylvestris L.) in Finland in 1963. Quantities of polyhedrosis virus preparation, collected and purified in Finland were available as concentrations packed in capsules. Spraying took place in three localities in southwestern Finland when the larvae were in I–III instars.

When Finnish and Swedish preparations were used 83–96% of larval colonies were completely destroyed within 14 days. In addition, an attempt was made to change the virus in latent stage, present already in the area, to acute stage by application of substrates which are probably harmless to pine, but were expected to stress the larvae. Ground quarts as spray had the best lethal effect upon larvae.

The PDF includes a summary in English.

  • Nuorteva, E-mail: mn@mm.unknown (email)
article id 4849, category Article
Pentti K. Räsänen, Tapani Hänninen. (1971). Eräiden talvivarastointimenetelmien vaikutuksesta männyn taimiin. Silva Fennica vol. 5 no. 3 article id 4849. https://doi.org/10.14214/sf.a14651
English title: The effect of some over-winter storage methods on different Scots pine nursery stock.
Original keywords: mänty; taimet; varastointi; talvivarastointi; kuolleisuus; kylmävarastointi
English keywords: Pinus sylvestris; Scots pine; planting; mortality; seedlings; cold storage; winter storage
Abstract | View details | Full text in PDF | Author Info

Seedlings of three different Scots pine (Pinus sylvestris L.) nursery stock, 1+0 ,1+1, and 2+0, were kept over the winter, after they had been packed in polythene bags, in three different ways: 1) In a refrigerated storage room, 2) in a wooden crate in the ground, 3) submerged in a lake. The seedling to which they were to be compared with were left over the winter in a nursery bed. The 1,800 seedlings were planted out in the spring 1966 in 15 random blocks. Their development was scrutinized during the three subsequent falls.

The seedlings which had been stored in the lake all died. The seedlings which had been stored along the 1st and 2nd method, managed almost as well as the ones which had been kept over the winter in the nursery bed, except for those of 1+0 stock.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
  • Hänninen, E-mail: th@mm.unknown
article id 4847, category Article
Pentti K. Räsänen, Matti Hiltunen. (1971). Männyn erilaisten taimierien istutuskelpoisuudesta. Silva Fennica vol. 5 no. 3 article id 4847. https://doi.org/10.14214/sf.a14649
English title: The effect of differences in Scots pine nursery stock on the field survival and growth.
Original keywords: mänty; metsänviljely; istutus; kasvu; taimet; varastointi; kastelu; kuolelisuus
English keywords: Pinus sylvestris; Scots pine; planting; growth; mortality; storage; seedlings; watering
Abstract | View details | Full text in PDF | Author Info

Scots pine (Pinus sylvestris L.) seedlings were stored for five days in an ordinary wood shed. One half of the seedlings were planted out directly, and another half after soaking the roots of the seedlings for 3–6 hours in water to compensate the possible water deficit developed. According to the results of the experiment, the effect of watering was extremely small. The difference observed, which was in favour of the trees that had been watered during storage, was discernible only in the needle length and in the number of lateral buds; in mortality or in the growth of the seedlings no difference could be observed.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
  • Hiltunen, E-mail: mh@mm.unknown
article id 4843, category Article
Unto Silvennoinen, Rihko Haarlaa. (1971). Metsätraktoreiden liikkuvuus lumessa. Silva Fennica vol. 5 no. 2 article id 4843. https://doi.org/10.14214/sf.a14645
English title: The mobility of logging tractors on snow.
Original keywords: puunkorjuu; metsäkuljetus; maastoluokitus; maasto; lumipeite; metsätraktorit; talvikorjuu
English keywords: snow; forest haulage; forwarder; timber harvesting; terrain; forest tractor; skidder; terrain classification
Abstract | View details | Full text in PDF | Author Info

The mobility of logging tractors was tested in the winter 1969 on difficult snow conditions to gather information for planning of logging operations and for logging machinery design. The tractors tested were Clark Ranger 666, Timberjack C, Valmet Terra, Ford Brunett 5000, Fiskars 510, BM-Volvo SM 660, BM Volvo SM 661, Ford Country 6, MF-Robur I and BM-Boxer T-350.

According to the results, there is a preference of tracked vehicles in difficult snow conditions compared to wheeled tractors. Ford Country with long and bearing full-tracks proved to have the best mobility. On downhill grades it was found significant differences between three-quarter-track-tractors and skidders, although the performance on level ground and uphill grades was relatively similar. The tracked vehicles can easier move on the packed snow layer and reach a higher speed.

The driving speed does not increase significantly until the density of snow has entirely changed through getting wet. Wet top layer of snow affects positively on driving, because it increases packing of the snow. Increasing density of the snow improves especially the mobility of broad-tired wheeled tractors. To be able to predict the driving speed of a tractor in winter working conditions one must know the depth of the snow layer and the density of the snow and the grade of the slope. In addition, the passages on the same route and the packing of the snow must be regarded.

The PDF includes a summary in English.

  • Silvennoinen, E-mail: us@mm.unknown (email)
  • Haarlaa, E-mail: rh@mm.unknown
article id 4840, category Article
Paavo Yli-Vakkuri. (1971). Havaintoja latvakasvainten pakkasvaurioista kuusen taimistoissa Itä-Savossa. Silva Fennica vol. 5 no. 2 article id 4840. https://doi.org/10.14214/sf.a14642
English title: Winter frost damages to the leaders of Norway spruce saplings in Eastern South-Finland.
Original keywords: kuusi; Itä-Savo; pakkasvauriot; pääverso
English keywords: Norway spruce; Picea abies; frost damages; leader shoots
Abstract | View details | Full text in PDF | Author Info

In the eastern parts of South-Finland the growing season of 1967 was highly favourable, which resulted in good height growth during the following year. During the summer 1968, temperature conditions were unfavourable, while the middle of summer was cold and the later part of the growing season unusually hot. The following winter had exceptionally cold spells from January to March, which caused Norway spruce (Picea abies (L.) H. Karst.) abundant winter frost damages such as dead shoots and buds, and destroyed needles.

These damages occurred particularly in stands with height of 0.5–3 m, and the occurrence of damages seemed to concentrate to the parts of saplings that had been immediately above the snow cover. Detailed observations on spruce plantations growing under a dense nurse stand of alder (Alnus sp.) indicated that explicitly the top shoots suffered from damages and not so much the laterals. When the needles of the leader suffered from minor damages, the shoot continued to grow normally. Still, sometimes a branch took over and became a new leader. If only the leader bud was killed, further stem development became dependent on one of the topmost lateral buds. When the upper part of the leaded died, one of the lateral shoots at its base usually became the new leader.

The PDF includes a summary in English.

  • Yli-Vakkuri, E-mail: py@mm.unknown (email)
article id 4835, category Article
Kari Löyttyniemi. (1971). Havupunkin, Oligonychus ununguis (Jacobi), aiheuttaman neulasvioituksen vaikutuksesta kuusen taimien kasvuun. Silva Fennica vol. 5 no. 1 article id 4835. https://doi.org/10.14214/sf.a14624
English title: Influence of damage caused to needles of Norway spruce by spruce spider mite, Oligonychus ununguis, on seedling growth.
Original keywords: kuusi; taimituhot; pituuskasvu; havupunkki; neulasvauriot
English keywords: Norway spruce; Picea abies; height growth; spruce spider mite; Oligonychus ununguis; needle damages
Abstract | View details | Full text in PDF | Author Info

The study was carried out in order to establish the possible influence of damage caused to the needles of Picea abies (L.) H. Karst. by the spruce spider mite, Oligonychus ununguis (Jacobi), and the growth of the damaged seedlings. The study was carried out in 1968–1970 by comparing growth of seedlings infected with spruce spider mite with that of seedlings where mites had been killed with acaricide (Eradex®). In the seedlings that had not been treated with acaricide, the number of wintering eggs were 60, 20 and 5 per shoot in the various years of the study. When the experiment was laid out, before planting and acaricide treatment, the seedlings were four years old, all seadlings were heavily infected, the number of wintering eggs being 100 per shoot. The growth of infected seedlings was 3, 20 and 15% smaller than that obtained for the seedlings which had been treated with acaricide.

The PDF includes a summary in English.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4834, category Article
Bo Långström. (1971). Weight loss, water content and mortality of cold stored Scots pine seedlings. Silva Fennica vol. 5 no. 1 article id 4834. https://doi.org/10.14214/sf.a14623
Keywords: Pinus sylvestris; Scots pine; mortality; seedlings; cold storage; weight loss; water content; storage conditions
Abstract | View details | Full text in PDF | Author Info

The aim of this study was to investigate how the weight loss and water content of cold stored plants depend on the storage conditions, and if there is a clear connection between these factors and the field survival of the planting stock. The experiments were carried out in a climate chamber at about +2°C and at three moisture levels (about 70, 85, and 95%) from November 1968 to May 1969. Three-year-old seedlings of Scots pine (Pinus sylvestris L.) average length 127 mm, diameter 3.5 mm and the top/root-ratio of fresh weight 1.93, were stored in open and sealed plastic bags. In addition, a transpiration retardant (Silvaplast) was used. The plastic bags (10 plants each) were weighted every 4. week. The remaining 270 seedlings were planted out and inspected after one growing season.

Although the experiment was made in a small scale, the results showed clearly that plant mortality, varying between 3 and 97%, was due to the storage conditions. The weight loss ranged between 2 and 50%, and the correlation between the weight loss and the mortality in the field was high. The water content of the seedlings was about 61%. The correlation between water content and survival was very high. Thus, the determination of weight loss or water content could be a useful method in observing the changes of water balance of the seedling stock during winter-storage. Further investigations are needed to show the tolerable rate of drying out for different sorts of plants. The Silvaplast-treatment had no visible effect either on the drying out or on the field survival.

The PDF includes a summary in English.

  • Långström, E-mail: bl@mm.unknown (email)
article id 4830, category Article
Matti Kärkkäinen. (1970). Optimaalisesta vinssausmatkasta. Silva Fennica vol. 4 no. 4 article id 4830. https://doi.org/10.14214/sf.a14619
English title: The optimum winching distance.
Original keywords: puunkuljetus; harvennushakkuu; puunkorjuu; ajourat; vintturit; vinssausmatka; korjuukustannukset
English keywords: forest haulage; forwarders; terrain transportation; strip roads; winching distance; harvesting costs
Abstract | View details | Full text in PDF | Author Info

The goal of this study was to develop a mathematical model for determination of the optimal winching distance in different conditions as based on harvesting costs. In the thinned forest the strip roads are parallel and the winching routes perpendicularly to them. A directed felling of trees is used so that it is easy to make loads to be winched. The stems can also be prepared to timber assortments on the stump area and gathered to loads for skidding alongside the winching routes.

After winching the timber is transported using a forwarder mowing on the strip roads. If the stems have not been bucked in the forests, they are to be prepared to timber assortments before the following transportation, because the problem of turning whole stems in a thinned forest has not yet been solved.

In the mathematical model the formation of the costs was described using 18 variables of which 15 had an effect on the optimum winching distance. Some empirical values were estimated concerning these variables, and the corresponding optimum winching distance were computed. The optimum was mainly determined by the quantity of timber harvested per unit area, the size of the winching load, the regression coefficient of the times which were depended on the winching distance.

According to the model, the deviation from optimum winching distance does not cause a very great change in the analysed total costs. When the winching distance is longer, the increase of the costs is smaller than if it is shorter than optimum. In general, the increase of the costs was so small that in practice one obviously can be satisfied with rather approximate methods in determining the suitable winching distance.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4829, category Article
Juhani Numminen. (1970). Metsäojituksen kannattavuuden alueittainen vaihtelu. Silva Fennica vol. 4 no. 4 article id 4829. https://doi.org/10.14214/sf.a14618
English title: Regional variation of the profitability of forest drainage in Finland.
Original keywords: metsänparannus; kannattavuus; metsäojitus; soiden ojitus; valtion tuet; avustukset; alueelliset erot
English keywords: forest drainage; subsidies; profitability; draining of peatlands; forest improvement; regional differences
Abstract | View details | Full text in PDF | Author Info

The study attempts to establish to what extent the present regional allocation of the forest improvement subsidies equalize the profitability of forest drainage in Finland. The benefit/cost ratio has been used to describe the regional variation of the profitability

The study revealed that the forest improvement subsidies granted in 1968, even the highest possible subsidies, did not equalize the profitability of forest drainage. According to the results, the northern regions are at a disadvantage compared to the southern parts of the country. To fully equalize the profitability of forest drainage the average subsidies granted in 1968 should have been raised in the second financing zone from 22 to 32%, in the third zone from 32 to 60%, and in the fourth, northernmost zone from 43 to 86%. The study also suggests that the boundary lines of the financing zones should run, at least in Central and Northern Finland, from southeast to northwest instead from east to west, as it is now.

The PDF includes a summary in English.

  • Numminen, E-mail: jn@mm.unknown (email)
article id 4819, category Article
Matti Kärkkäinen. (1970). Hakkuutähteiden merkityksestä puuston vaurioitumisen ja raiteenmuodostuksen kannalta harvennusmetsissä. Silva Fennica vol. 4 no. 2 article id 4819. https://doi.org/10.14214/sf.a14608
English title: Significance of logging waste in thinnings as to scars and tracks in the terrain.
Original keywords: maaperä; harvennushakkuu; puunkorjuu; metsäkuljetus; hakkuutähteet; metsäkoneet; maastovauriot; puustovauriot; ajourat; kantavuus
English keywords: thinnings; forest haulage; soil; timber harvesting; terrain transportation; strip roads; logging waste; tree injuries; stem injuries; tracks; carrying capacity
Abstract | View details | Full text in PDF | Author Info

The purpose of this study was to explain whether it is possible to affect, in practical working site conditions, by means of logging waste on the strip road, the depth of the track which is formed in terrain transportation and the injuries of the growing stand. Five 20 m long investigation areas with logging waste and five similar areas without logging waste were arranged on one strip road at Teisko logging site in Southern Finland. The logging waste layer was mainly Norway spruce and 10–15 cm thick. A KL–836 B forwarder was used. The type of soil was loam.

The logging waste affected the depth of the track only by decreasing the wear of humus layer. Even decreasing effect of logging waste on the injuries in the growing stand was minor. At Kitee working site in Eastern Finland strip roads were studied. The type of soil was thick, rather mouldered peat. The thickness of logging waste was 3–4 times greater than in Teisko, mainly spruce. A Volvo Nalle SM 460 forwarder was used. The effect of the logging waste on the depth of the tracks was clearly to be noticed. On basis of the appearance of the tracks one could assume that the difference was due to different wear of the humus, and not so much due to the quantity of logging waste that improves the carrying capacity of terrain.

In some extent logging waste was also found to affect the amount and quality of tree injuries. In practical working conditions, the importance might be small, since in the experiments an unrealistically great amount of logging waste was used.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4813, category Article
Bo Långström. (1970). Pakkaustapojen vaikutuksesta talvivarastoitujen männyn taimien istutukseen. Silva Fennica vol. 4 no. 1 article id 4813. https://doi.org/10.14214/sf.a14602
English title: The effect of packing methods on the field survival and growth of winter-stored plants of Scots pine.
Original keywords: mänty; metsänviljely; istutus; kasvu; taimet; kylmävarasto; talvivarastointi; kuolleisuus; tukkimiehentäi; torjunta-aine
English keywords: Pinus sylvestris; nursery; Scots pine; planting; seedlings; cold storage; winter storage; Hylobious abietis; large pine weevil; insecticide; field survival; packing methods
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to investigate the effect of four packing methods on the field survival and growth of seedlings and transplants of Scots pine (Pinus sylvestris L.) stored over the winter in a cold-storage cellar. The following sorts of plants were used: one-year-old seedlings (1+0) grown in a plastic greenhouse, two-year-old (2+0) open grown seedlings and three-year-old open grown transplants. These plants were stored in open wooden boxes, in sealed plastic bags, in boxes with wet peat on the bottom and in plastic-laminated paper bags.

The control plants were of the same types and were kept in a nursery over the winter. The storage was carried out in a mantle-chilled cold-storage from October 1966 to May 1967. The temperature in the cold-storage was kept around -2 °C and the relative humidity of the air over 90%. The water content of a randomly selected sample plants showed no increase in water deficit after the storing. Part of the seedlings were transplanted in the nursery and the rest were planted in a clear-cut area. A number of the latter plants were treated with an insecticide (1% Intaktol, which contains DDT, Lindane and dieldrin) before planting. All the experiments were examined after one growing season and the planting experiments the next fall.

The transplants (2+1) in the nursery, and in the forest had survived and grown better than the seedlings. In the nursery the 1+0 seedlings survived and grew better than the 2+0 seedlings. There was no difference in mortality between the seedlings. After the first growing season occasional significant differences between the packing methods were observed, but they disappeared during the second growing season. Thus, all packing methods proved to be as successful as the control method without winter storage.

Transplants were more often attacked by the large pine weevil (Hylobius abietis L.) than the smaller seedlings. The damage, however, was considerably greater on the seedlings because of their lower resistance. No significant differences in the Hylobius-attack between the packing methods could be observed. The Intaktol-treated plants were as often attacked as the untreated ones, but the damage was slighter on the treated ones.

The PDF includes a summary in English.

  • Långström, E-mail: bl@mm.unknown (email)
article id 4812, category Article
Pentti K. Räsänen, Aarno Koukkula, Paavo Yli-Vakkuri. (1970). Pakkauksen, varastoimisen ja valeistutuksen vaikutus männyn taimien istutuskelpoisuuteen. Silva Fennica vol. 4 no. 1 article id 4812. https://doi.org/10.14214/sf.a14601
English title: The effect of packing, storing and heeling-in on the field survival and growth of Scots pine seedlings.
Original keywords: mänty; metsänviljely; istutus; metsäpuun taimet; taimet; varastointi; kuolleisuus; kastelu; tukkimiehentäi
English keywords: Pinus sylvestris; Scots pine; planting; mortality; storage; Hylobius abietis; seedlings; large pine weevil; insecticide; field survival
Abstract | View details | Full text in PDF | Author Info

The aim of the present study was to establish, by means of planting experiments, the influence of different packing, heeling-in and watering as well as the length of the storage period on the development of Scots pine (Pinus sylvestris L.) seedlings, in all 2,090 seedlings, that had been lifted from the nursery bed in spring. The plants were packed in bundles and into plastic sacks in 1965 (6 storage methods) and in 1966 (3 storage methods). Control seedlings were planted without storing at the time when storage of the test material begun. The plantations were followed 3–4 years.

Storage for two weeks in the different ways and planting without storage gave similar results when seedling survival was compared. Storage in plastic sack proved to be as good as storage in bundles in a cellar, and healing-in in moist soil or in a drain were both usable methods. Watering the seedlings did not improve the results, which indicates that the storage caused no serious lack of water.

After four growing seasons an average of 19,6% of the seedlings of the 1965 experiment died, the bulk of them by the end of the first growing season. Despite control treatment, Hylobious abietis caused serious damages. In the plantations of the year 1966 mortality of the seedlings was under 5% by the end of third growing season. During the first two growing seasons after planting differences in growth of the seedlings stored in different ways could be observed in the plantations of the year 1965, but the differences levelled out later. In the plantations established in 1966 no differences in growth occurred.

The PDF includes a summary in English.

  • Räsänen, E-mail: pr@mm.unknown (email)
  • Koukkula, E-mail: ak@mm.unknown
  • Yli-Vakkuri, E-mail: py@mm.unknown
article id 4810, category Article
Pentti Solin. (1970). Kuusen käpyjen säilyttäminen jäähdyttämössä ja sen vaikutus niistä saatavan siemenen itävyyteen. Silva Fennica vol. 4 no. 1 article id 4810. https://doi.org/10.14214/sf.a14598
English title: Cold storage of Norway spruce cones and its effect on seed viability.
Original keywords: kuusi; varastointi; siemenet; itävyys; kävyt; kylmävarasto
English keywords: Norway spruce; Picea abies; germination; storage; viability; seeds; cones; cold storage
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to establish how the cold storage of cones of Norway spruce (Picea abies (L.) H. Karst.) affects the viability of the seeds and the percentage ratio in 7 days. A parallel study was made of the longevity of seed in barn-stored cones subject to weather fluctuations and the longevity of seed extracted immediately and stored in the conventional way in an air-tight container. The cones were collected near Kuopio in Central Finland and near Tampere.

The viability and germination rate of the control sample was constant throughout the storage period. This storage method proved the best. The viability of seeds kept in cones declined in cold storage after 3 ½ months. The cones collected in Tampere were damaged by Laspeyresia strobilella, which affected the viability of the seeds.

The viability of seeds stored in cones in a barn had not weakened by the end of May, however, they deteriorated during the summer, as did the seeds stored in cones in the cold storage. Viability of the seeds was still 94% in October. The germination rate was constant in each lot up to the end of May, after which it decreased to 81.7–86.1% in October.

The results show that healthy spruce cones can be stored in paper sacks in a single layer in cold storage and in an ordinary barn for several months without it affecting the viability of the seeds.

The PDF includes a summary in English.

  • Solin, E-mail: ps@mm.unknown (email)
article id 4802, category Article
Kari Löyttyniemi. (1969). Äkämäpunkkilaji (Nalepella haarlovi var. piceae-abietis Löyttyniemi, Acarina, Eriophyidae) kuusen taimien tuholaisena taimitarhoissa. Silva Fennica vol. 3 no. 3 article id 4802. https://doi.org/10.14214/sf.a14590
English title: An Eriophyidae species damaging Norway spruce seedlings in nurseries in Finland.
Original keywords: kuusi; hyönteistuhot; taimitarha; taimikasvatus; neulaspunkki; kuusen taimet; punkit
English keywords: Norway spruce; Picea abies; needles; seedling damages; nurseries; Acarina; Eriophyidae; Nalepella Haarlovi var. picea-abietis; Nalepella Haarlovi; mites
Abstract | View details | Full text in PDF | Author Info

In Finland the mite Nalepella is found in Norway spruce (Picea abies (L.) H. Karst.) in forests practically in every tree, and even in the nurseries. The paper reports on the occurrence of Nalepella Haarlovi var. picea-abietis Löyttyniemi in Finland in tree nurseries in Finland. The study is based on a large material, collected in connection with an investigation into spruce spider mites.

Nalepella lives vagrantly on the needles. Due to the sucking of the mites, the needles turn yellow, become dry an die. Single patches from sucking cannot be seen by the naked eye. They occur on all sides of the needles. The worst damage to spruce seedlings in nurseries is caused to the needles located in the top of the seedling. Sometimes the terminal bud dryes and the whole terminal shoot can die. However, the whole seedlings seldom die in consequence of the Nalepella mite alone. Subsequent damage to the injured needles is often caused by fungus Cladosporium herbarum.

The study shows that the mite causes economically significant damages only in the nurseries. In forests no such damages were observed in seedlings or in older trees. In 1965–68, significant damages occurred in 16 nurseries in Finland. About 600,000 four-year-old seedlings were destroyed in 1967. The damages were economically important only in the 4-year-old seedlings.

According to the study, seedlings damaged by Nalepella can be used for planting as they recover rather well after planting in the forest. Moreover, the damages end after planting, and density of the mite population decreases during the first summer.

The mite overwinters as egg on needles. The eggs hatch in Southern Finland in the end of April and in the beginning of May.

The PDF includes a summary in English.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4801, category Article
Rihko Haarlaa. (1969). Puunkorjuun suunnittelu ja metsätaloussuunnitelmat. Silva Fennica vol. 3 no. 3 article id 4801. https://doi.org/10.14214/sf.a14589
English title: The role of logging in forest management plans.
Original keywords: hakkuu; puunkuljetus; metsäsuunnittelu; puunkorjuu; metsäsuunnitelmat; metsätaloussuunnitelmat
English keywords: logging; timber harvesting; felling; transportation; forest management plan; forest working plan
Abstract | View details | Full text in PDF | Author Info

The purpose of this study was to answer questions concerning the basic information in planning of timber harvesting, how this information has to be handled, and how the planning of logging has to be combined with other forest management planning.

A deductive research method was used. By analysing a logging plan, prepared for a certain forest area, general conclusions were reached. To prepare the logging plan in connection with the forest management plan, the following information was found to be necessary: boundaries of the area, extent and ownership of the planned area, maps including information of the location of the timber and the conditions for transportation, road network and a reliable picture of the difficulty of the forest terrain.

Based on the material of the present timber harvesting methods it will be possible to predict the logging methods which will be applicable in the near future. The object to be planned has to be divided to operation areas. The amount of manpower and equipment needed can be estimated for each phase of the timber harvesting chain on the basis of the information calculated in this manner. Investments to machines and basic improvement works have to be planned before the effect of planning can be calculated in the logging costs, which are to be minimized. Due to the rapid development of the field, the handling of the material in connection with a forest management plan has to be left partly unfinished since the development of future logging methods cannot be reliably predicted.

The PDF includes a summary in English.

  • Haarlaa, E-mail: rh@mm.unknown (email)
article id 4800, category Article
Veli-Pekka Järveläinen. (1969). Metsänhoidolliset mielipiteet ja metsänhoidollinen toiminta maatilametsätaloudessa. Silva Fennica vol. 3 no. 3 article id 4800. https://doi.org/10.14214/sf.a14588
English title: Opinions about silviculture in farm forestry in Finland, and practical steps taken.
Original keywords: metsänhoito; maatilametsätalous; Suomi; metsänomistajat; asenteet; asennetutkimus; Jämsä; Karstula; metsäneuvonta; mielipidetutkimus
English keywords: forest management; silviculture; Finland; forest owners; farm forestry; attitudes; opinion poll; opinions
Abstract | View details | Full text in PDF | Author Info

The purpose of this study was to find out about the forest owner’s views on silviculture and any forest management work he had carried out. The data is based on interviews of 289 forest owners in municipalities of Jämsä and Karstula in Central Finland in 1966. The forest owners were a random sample of all males in the municipalities, who alone or together with their wives were in the possession of at least 2 ha of cultivated land and 10 ha of forests.

The forest owners’ attitudes towards silviculture were generally favourable. A common opinion was that money spent on silviculture is a paying proposition (88%), that forest management is better today than it used to be (87%), that cultivation of forests is an economic proposition (81%), and that few owners manage their forests properly unless forced by the law (79%). The need for planning silvicultural measures was also generally accepted (78%).

However, few agreed that the legally imposed silvicultural fee is necessary, that the new silvicultural methods were practicable, or that money he invested in silviculture is profitable to the forest owner. Only 45% agreed that forestry experts have sufficient understanding of the owner’s needs. One third of the forest owners had carried out the following silvicultural tasks: forest cultivation, forest drainage or forest fertilization, on a minimum area of five hectares. Forest cultivation had been carried out by 63%, forest drainage by 44% and forest fertilization by 16% of the respondents. Vast majority (90%) had employed forest experts and a many nearly every year, mainly for marking the trees to be felled.

In the more rural municipality of Karstula, the forest owners’ views towards forestry was more favourable than in the semi-industrialized Jämsä.

The PDF includes a summary in English.

  • Järveläinen, E-mail: vj@mm.unknown (email)
article id 4778, category Article
Kari Löyttyniemi. (1968). Teeri (Lyrurus tetrix L.) männyn taimien tuholaisena taimitarhassa. Silva Fennica vol. 2 no. 4 article id 4778. https://doi.org/10.14214/sf.a14563
English title: Feeding of terminal shoots of Scots pine seedlings by the black grouse (Lyrurus tetrix) in nursery.
Original keywords: mänty; taimitarha; taimituhot; versot; teeri
English keywords: Pinus sylvestris; nursery; Scots pine; forest nursery; seedling damages; feeding behaviour; black grouse; Lyrurus tetrix; terminal buds
Abstract | View details | Full text in PDF | Author Info

In early spring 1968 it was noticed that the black grouses (Lyrurus tetris L.) was eating terminal shoots of Scots pine (Pinus sylvestris L.) seedlings in a tree nursery in Luumäki, Southern Finland. The terminal shoots were picked 1–4 cm from the top of the seedlings. In total some thousands of two-year-old seedlings were damaged. The depth of the snow was 10–15 cm deep and only the tops of the seedlings could be seen above the surface of the snow.

The PDF includes a summary in English.

  • Löyttyniemi, E-mail: kl@mm.unknown (email)
article id 4774, category Article
Pekka Kilkki. (1968). Some economic aspects of growing forest stands. Silva Fennica vol. 2 no. 4 article id 4774. https://doi.org/10.14214/sf.a14559
Keywords: forest management; fellings; growing shedule; rotation; current gross soil rent; value growth; rent of the growing stock
Abstract | View details | Full text in PDF | Author Info

The aim of this paper was that of studying the optimum growing schedules of forest stands, with the classic Faustmann formula as starting point. The study is mainly theoretical in nature. The study shows that the net present-value of the future revenues from a forest stand can be calculated, not only by means of the harvesting revenues, but also by a more theoretical concept, here termed the current gross soil rent. The current gross soil rent represents the difference between the current value growth and the rent of the growing stock.

By use of the concepts described here, it is theoretically possible to find the growing schedule for the stand which maximizes the net present-value of the stand. To make the formulae simpler, a one-year period has been adopted for discussion of the concepts involved in determination of the optimum structure and density of the growing stock, and the financial maturity. However, these concepts can be extended to cover periods of any length.

The method for determination of the optimum growing schedule for a forest stand can be summarized as follows: Thin the stand as the internal rate of return on the marginal increase in ’timber capital’ falls below the guiding rate of interest. Clear-cut and regenerate the stand as the internal rate of return on the sum of the ’timber and soil capital’ falls below the guiding rate of interest.

The PDF includes a summary in Finnish.

  • Kilkki, E-mail: pk@mm.unknown (email)
article id 4770, category Article
Kustaa Seppälä. (1968). Ennakkotuloksia suometsiköiden ojituksen jälkeisestä kehityksestä ja siihen vaikuttavista tekijöistä. Silva Fennica vol. 2 no. 3 article id 4770. https://doi.org/10.14214/sf.a14555
English title: Preliminary results of post-drainage development of peatland stands in Finland.
Original keywords: kasvu; suometsät; turvekankaat; ojitetut suot; kuivatustehokkuus; ojaväli
English keywords: drained peatlands; increment; draining intensity; ditch interval; drainage effect; stand recovery
Abstract | View details | Full text in PDF | Author Info

The present paper is a preliminary report of a project designed to determine the order of profitability of various forest improvement measures – seeding and planting, drainage, and fertilization – in various types of stands and in different parts of the country on drained peatlands. Sample plot data on the effect of draining on increment was derived from areas drained 28– 36 years ago. The study was carried out in the southern half of Finland.

The observations on increment changes are based on two measurements of the sample stands 12 years apart. Supplementary calculations indicate that the stands on drained peatland, depending on site quality and tree species, have either continued to grow like mineral-soil sites of similar fertility or have somewhat increased their growth rate.

The effect of draining intensity was studied using strip measurements. It was found that both the total amount of wood produced (current stand + cutting removal + natural removal) and the current annual volume increment for the 5-year period systematically decrease as the ditch interval increases. The decrease is, however, relatively slight. In Eriophorum vaginatum pine swamps, the total amount of wood produced and the increment show a decrease of ca. 20% with an increase in ditch interval from 20 to 60 metres. In other sites, the decrease is ca. 5-10%

It can be concluded that if the increase in ditch interval do not result in considerably poorer timber assortment distributions than indicates by stand production and increment, it is profitable to pan for a relatively large ditch interval and a slightly smaller than maximum wood production. Supplementary data and check calculations may cause some changes in these preliminary results.

The PDF includes a summary in English.

  • Seppälä, E-mail: ks@mm.unknown (email)
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 4733, category Article
Mikko Ilvessalo, Yrjö Ilvessalo. (1966). Suomen pienmetsätalouden tutkimuksessa v. 1930 inventoitujen pienmetsälöiden kehityksestä vuodesta 1930 vuosiin 1963-64. Silva Fennica vol. no. 119 article id 4733. https://doi.org/10.14214/sf.a14291
English title: Development of small forest holdings between 1930 and 1963–64 in Finland.
Original keywords: metsänhoito; yksityismetsät; metsävarat; pientilat; Suomi; pienmetsätalous
English keywords: forest management; Finland; forest resources; private forests; small holdings
Abstract | View details | Full text in PDF | Author Info

In the 1930s studies showed that state of the standing crop and forests of small private forest holdings in Finland was weak. In 1960s it was regarded necessary to study the possible change in the silvicultural state of these forests. Therefore, sample stands of the small holdings surveyed in 1930 by Osara were surveyed anew in the areas of Karelia and Savo, and in Central Finland in 1963–1964. A line plot survey was combined with ocular estimation as in 1930, but in 1963–1964 the lines and sample plots were placed denser than in 1930 to reach similar number of sample plots.

In 1930 the state of the forests of the small holdings was in average very weak, but according to Osara, the age classes younger than 50 years had similar stand volume than in the all the forests of the southern half of the country. The results of this survey show that the volume, structure, growth and development class structure of the forests in average have improved since 1930. In many respects the forests have reached the average state of forests in the southern half of Finland. The most serious problem is the large proportion of broadleaved trees. Thus, the silvicultural state of the forests should be further improved.

The PDF includes a summary in German.

  • Ilvessalo, E-mail: mi@mm.unknown (email)
  • Ilvessalo, E-mail: yi@mm.unknown
article id 4727, category Article
Erkki Pulliainen, Kalervo Salonen. (1965). Orava männyn siemen- ja silmutuholaisena. Silva Fennica vol. no. 117 article id 4727. https://doi.org/10.14214/sf.a14285
English title: Damage caused by squirrel (Sciurus vulgaris) to pine-buds.
Original keywords: mänty; taimituhot; kasvutappiot; orava; silmut
English keywords: Pinus sylvestris; Scots pine; seedling damages; squirrels; Sciurus vulgaris; buds
Abstract | View details | Full text in PDF | Author Info

When the seed harvest of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) are low, pine and spruce buds are among the secondary food items of squirrel (Sciurus vulgaris L.) in Finland. In this study, conducted in Nokia in Southern Finland in 1962-1963, eating of pine buds by squirrel is described. The eaten buds in 15-years old Scots pine seedlings were recorded in two seedling stands.

According to the results, the squirrels selected the largest buds of the best seedlings in the studied stands. In over 50% of the cases the squirrels chose only the buds of the leading shoot, especially the terminal bud. In half of the trees, a side bud of the leading shoot continued the growth, which causes form defects in the trees. In 35% of the damaged trees, a lateral branch continued the growth. Well-growing seedling stands may be especially susceptible for damages caused by, for instance, squirrels.

The PDF includes a summary in Finnish.

  • Pulliainen, E-mail: ep@mm.unknown (email)
  • Salonen, E-mail: ks@mm.unknown
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 vol. 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 4720, category Article
Veijo Heiskanen. (1964). Aikatutkimuksia koivun karsimisesta. Silva Fennica vol. no. 115 article id 4720. https://doi.org/10.14214/sf.a14279
English title: Time studies in the pruning of birch.
Original keywords: metsänhoito; metsätyö; työntutkimus; aikatutkimus; karsinta
English keywords: forest management; pruning; time studies; forest work; work studies
Abstract | View details | Full text in PDF | Author Info

On the basis of time studies on pruning, one thousand stems in four stands was pruned, carried out in 1962. The work was done in two phases with Olli pruning saw, first attached to a shaft about 1.8 metres long and the to a shaft about 4 metres long.

The total time of moving from one stem to another when pruning the stem varied from 0,28 to 0.31 min per stem in the different working sites. The resting time was 19–20% of the effective working time, which included actual pruning time and the moving time. In average, 7.5% of the actual pruning time was unproductive. The actual pruning took in average 0.75–1.1 min/stem in the different sites. The time depended on size of the tree, the DBH, and on the length of the part to be pruned. The total working site time for the pruning was in average 1.34–1.98 min/stem. The output of the work per 7 hours’ working day varied from 226 to 280 stems, and the costs from 10 to 14 pennies per stem.

The PDF includes a summary in English.