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Articles containing the keyword 'weight'.

Category: Research article

article id 1239, category Research article
Tomi Kaakkurivaara, Nuutti Vuorimies, Pauli Kolisoja, Jori Uusitalo. (2015). Applicability of portable tools in assessing the bearing capacity of forest roads. Silva Fennica vol. 49 no. 2 article id 1239. https://doi.org/10.14214/sf.1239
Highlights: The dynamic cone penetrometer (DCP) and light falling weight deflectometer (LFWD) are useful tools for measuring bearing capacity; The measurement results are not same as with the falling weight deflectometer (FWD), but comparable.
Forest roads provide access to logging sites and enable transportation of timber from forest to mills. Efficient forest management and forest industry are impossible without a proper forest road network. The bearing capacity of forest roads varies significantly by weather conditions and seasons since they are generally made of poor materials and the constructed layers may be mixed with subgrade. A bearing capacity assessment is valuable information when trafficability is uncertain and rutting is obvious. In this study, bearing capacity measurements were carried out using the light falling weight deflectometer (LFWD), the dynamic cone penetrometer (DCP) and the conventional falling weight deflectometer (FWD). The aim was to compare their measurement results in relation to road characteristics and moisture conditions. Data were collected from 35 test road sections in four consecutive springs and during one summer. The test road sections had measurement points both on the wheel path and the centre line. The data show logical correlations between measured quantities, and the study presents reliable regression models between measuring devices. The results indicate that light portable tools, the DCP and the LFWD, can in most cases be used instead of the expensive falling weight deflectometer on forest roads.
  • Kaakkurivaara, Natural Resources Institute Finland, Green technology, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: tomi.kaakkurivaara@gmail.com (email)
  • Vuorimies, Tampere University of Technology, P.O.Box 600, FI-33101 Tampere, Finland ORCID ID:E-mail: nuutti.vuorimies@tut.fi
  • Kolisoja, Tampere University of Technology, P.O.Box 600, FI-33101 Tampere, Finland ORCID ID:E-mail: pauli.kolisoja@tut.fi
  • Uusitalo, Natural Resources Institute Finland, Green technology, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: jori.uusitalo@luke.fi
article id 1239, category Research article
Tomi Kaakkurivaara, Nuutti Vuorimies, Pauli Kolisoja, Jori Uusitalo. (2015). Applicability of portable tools in assessing the bearing capacity of forest roads. Silva Fennica vol. 49 no. 2 article id 1239. https://doi.org/10.14214/sf.1239
Highlights: The dynamic cone penetrometer (DCP) and light falling weight deflectometer (LFWD) are useful tools for measuring bearing capacity; The measurement results are not same as with the falling weight deflectometer (FWD), but comparable.
Forest roads provide access to logging sites and enable transportation of timber from forest to mills. Efficient forest management and forest industry are impossible without a proper forest road network. The bearing capacity of forest roads varies significantly by weather conditions and seasons since they are generally made of poor materials and the constructed layers may be mixed with subgrade. A bearing capacity assessment is valuable information when trafficability is uncertain and rutting is obvious. In this study, bearing capacity measurements were carried out using the light falling weight deflectometer (LFWD), the dynamic cone penetrometer (DCP) and the conventional falling weight deflectometer (FWD). The aim was to compare their measurement results in relation to road characteristics and moisture conditions. Data were collected from 35 test road sections in four consecutive springs and during one summer. The test road sections had measurement points both on the wheel path and the centre line. The data show logical correlations between measured quantities, and the study presents reliable regression models between measuring devices. The results indicate that light portable tools, the DCP and the LFWD, can in most cases be used instead of the expensive falling weight deflectometer on forest roads.
  • Kaakkurivaara, Natural Resources Institute Finland, Green technology, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: tomi.kaakkurivaara@gmail.com (email)
  • Vuorimies, Tampere University of Technology, P.O.Box 600, FI-33101 Tampere, Finland ORCID ID:E-mail: nuutti.vuorimies@tut.fi
  • Kolisoja, Tampere University of Technology, P.O.Box 600, FI-33101 Tampere, Finland ORCID ID:E-mail: pauli.kolisoja@tut.fi
  • Uusitalo, Natural Resources Institute Finland, Green technology, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: jori.uusitalo@luke.fi
article id 132, category Research article
Mats Berlin, Lars Lönnstedt, Gunnar Jansson, Öje Danell, Tore Ericsson. (2010). Developing a Scots pine breeding objective: a case study involving a Swedish sawmill. Silva Fennica vol. 44 no. 4 article id 132. https://doi.org/10.14214/sf.132
The aim of this study was to develop a Scots pine (Pinus sylvestris L.) breeding objective for a vertically integrated sawmill in northern Sweden. The production system was defined as comprising the sawmill and the forests supplying it. Volume per hectare, wood density, survival and straightness were used as objective traits and the related selection criteria were measurements, collected at young tree age, of height, diameter, pilodyn penetration, vitality and straightness. A bio-economic model was used to calculate economic weights for the objective traits identified. We also investigated the efficiency of different selection indices based on these economic weights, in combination with available data on genetic parameters. Furthermore, we studied the effect of different discount rates on the calculated economic weights. The results showed that, compared to the full index (which included all selection criteria), omitting either vitality or straightness had a negligible effect, reducing predicted profit gain per hectare by less than one per cent. Height or diameter each had a greater effect, with a loss of predicted profit gain per hectare of up to 6%. Excluding pilodyn penetration from the selection index caused the largest reduction in predicted profit gain per hectare, amounting to over 10%. However, when both height and diameter were removed the predicted profit gain per hectare dropped to one-third of that based on the full index. Finally, ranking and genetic selection for the developed breeding objective was insensitive to changes in the discount rate.
  • Berlin, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: mats.berlin@skogsforsk.se (email)
  • Lönnstedt, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Jansson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Danell, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
  • Ericsson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail:
article id 596, category Research article
Sakari Tuominen, Simo Poso. (2001). Improving multi-source forest inventory by weighting auxiliary data sources. Silva Fennica vol. 35 no. 2 article id 596. https://doi.org/10.14214/sf.596
A two-phase sampling design has been applied to forest inventory. First, a large number of first phase sample plots were defined with a square grid in a geographic coordinate system for two study areas of about 1800 and 4500 ha. The first phase sample plots were supplied by auxiliary data of Landsat TM and IRS-1C with principal component transformation for stratification and drawing the second phase sample (field sample). Proportional allocation was used to draw the second phase sample. The number of field sample plots in the two study areas was 300 and 380. The local estimates of five continuous forest stand variables, mean diameter, mean height, age, basal area, and stem volume, were calculated for each of the first phase sample plots. This was done separately by using one auxiliary data source at a time together with the field sample information. However, if the first phase sample plot for which the stand variables were to be estimated was also a field sample plot, the information of that field sample plot was eliminated according to the cross validation principle. This was because it was then possible to calculate mean square errors of estimates related to a specific auxiliary data source. The procedure produced as many estimates for each first phase sample plot and forest stand variable as was the number of auxiliary data sources, i.e. seven estimates: These were based on Landsat TM, IRS-1C, digitized aerial photos, ocular stereoscopic interpretation from aerial photographs, data from old forest inventory made by compartments, Landsat TM95–TM89 difference image and IRS96–TM95 difference image. The final estimates were calculated as weighted averages where the weights were inversely proportional to mean square errors. The alternative estimates were calculated by applying simple rules based on knowledge and the outliers were defined. The study shows that this kind of system for finding outliers for elimination and a weighting procedure improves the accuracy of stand variable estimation.
  • Tuominen, Finnish Forest Research Institute, Unioninkatu 40 A, FIN-00170 Helsinki, Finland ORCID ID:E-mail: sakari.tuominen@metla.fi (email)
  • Poso, Department of Forest Resource Management, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:

Category: Article

article id 7259, category Article
I. Lassila. (1929). Metsätyypin vaikutuksesta puun painoon. Acta Forestalia Fennica vol. 36 no. 1 article id 7259. https://doi.org/10.14214/aff.7259
English title: The influence of forest site type on the weight of wood.

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

The PDF includes a summary in English.

  • Lassila, ORCID ID:E-mail:
article id 5530, category Article
Anna Saarsalmi, Erkki Lipas, Jouni Mikola, Teijo Nikkanen, Eira-Maija Savonen. (1994). Effect of fertilization on flowering and seed crop in Scots pine seed orchards. Silva Fennica vol. 28 no. 3 article id 5530. https://doi.org/10.14214/sf.a9170

The aim of the study was to obtain information needed in preparing more precise fertilization recommendations for seed orchards. The fertilization requirement was estimated on basis of soil and needle analyses, and by investigating the effects of different fertilization treatments on male and female flowering, size of seed crop and seed quality.

The study was carried out in two Scots pine (Pinus sylvestris L.) seed orchards in Southern Finland, one established on forest soil in 1971 and 1972, and the other on a peat field in 1974. 10 clones and 39 grafts from each clone were selected randomly from both orchards in autumn 1985. The treatments consisted of N, P and K in various combinations, micronutrients, wood ash and grass control. The orchards were fertilized in spring 1986.

There were statistically significant differences between the clones in both orchards as regards amount of flowers, size of the seed crop and seed quality. The annual variation in flowering and the size of the seed crop was also large. In general, the seeds from cones collected in October matured well and their germination percentage was high. The effects of fertilization on flowering, the size of seed crop and seed quality were small. It would appear that the size of the crop can be affected to a much greater extent by favouring clones with a high seed-producing capacity than through fertilization. Fertilization is unnecessary if the nutrient status of the soil is satisfactory.

  • Saarsalmi, ORCID ID:E-mail:
  • Lipas, ORCID ID:E-mail:
  • Mikola, ORCID ID:E-mail:
  • Nikkanen, ORCID ID:E-mail:
  • Savonen, ORCID ID:E-mail:
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

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, ORCID ID:E-mail:
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

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, ORCID ID:E-mail:
article id 5432, category Article
Risto Rikala, Helen J. Jozefek. (1990). Effect of dolomite lime and wood ash on peat substrate and development of tree seedlings. Silva Fennica vol. 24 no. 4 article id 5432. https://doi.org/10.14214/sf.a15586

Effect of dolomite lime and wood ash (0, 0.5, 1, 2, 4, 8 and 16 kg m-3) on the chemical composition of low humified Sphagnum peat was studied. Germination of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) and silver birch (Betula pendula Roth) and the subsequent growth of these seedlings were investigated in a greenhouse experiment. Nutrient concentrations in shoots and roots of pine seedlings were also analysed. The pH of peat increased asymptotically from 3.8 to about 7.0 with increasing lime regimen and to about 8.0 with increasing ash regimen. Wood ash linearly increased electrical conductivity and P, K, and Ca concentrations of peat. Rate of germination, within 7 days, of pine and spruce was best at low pH (<5) while birch seeds had a slightly higher pH optimum (4–6). Germination capacity, within 21 days, was not affected by pH or application regimen of either lime or ash. Pine and spruce seedlings grew best with lime and ash doses of 0.5–2.0 kg m-3, the pH of peat being 4–5. Lime and ash treatments did not affect the growth of birch seedlings, but wood ash increased nutrient concentration of pine seedlings.

The PDF includes an abstract in Finnish.

  • Rikala, ORCID ID:E-mail:
  • Jozefek, ORCID ID:E-mail:
article id 4834, category Article
Bo Långström. (1971). Viktförlust, vattenhalt och plantavgång hos kyllagrade tallplantor. Silva Fennica vol. 5 no. 1 article id 4834. https://doi.org/10.14214/sf.a14623
English title: Weight loss, water content and mortality of cold stored Scots pine seedlings.

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, ORCID ID:E-mail:
article id 4783, category Article
Juhani Päivänen. (1969). The bulk density of peat and its determination. Silva Fennica vol. 3 no. 1 article id 4783. https://doi.org/10.14214/sf.a14569

This study determined the correlation between the bulk density, humification degree and laboratory volume weight of the surface peat of virgin and drained peatlands. The material consists of 316 peat samples 250 cc in volume.

The correlation between bulk density and the laboratory volume weight was found to be close. Eliminating the ash and moisture content of air-dry samples did not improve the correlation. There were distinct level differences among peat types; difference between bulk density and laboratory volume weight was the greatest for Sphagnum and the smallest for woody peats. The Carex peats were intermediate. The water content at sampling may partly determine these differences. When the data were treated as a whole, the difference between bulk density and laboratory volume weight seemed to increase, as the water content increased.

The correlation was also close between bulk density and the degree of humification. For all data, multivariable correlation analysis revealed that bulk density was determined for the largest part by the degree of humification, least by the water content at sampling, laboratory volume weight being intermediate. Thus, already the determination of the degree of humification provides a clear picture of the bulk density for each peat type. It can be also determined by fair accuracy on the basis of the laboratory volume weight. The bulk density is required for e.g. water regime studies, to convert the water content of peat measured in weight units into volume percentages.

The PDF includes a summary in Finnish.

  • Päivänen, ORCID ID:E-mail:
article id 4701, category Article
Veijo Heiskanen. (1960). Tutkimuksia koivuhalkojen painosta ja kosteudesta. Silva Fennica no. 108 article id 4701. https://doi.org/10.14214/sf.a9136
English title: Studies on the weight and moisture of split birch fuel wood.

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

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

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

The PDF includes a summary in English.

  • Heiskanen, ORCID ID:E-mail:

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