Current issue: 53(3)

Under compilation: 53(4)

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

Category: Research article

article id 10161, category Research article
Jussi Manner, Anders Mörk, Martin Englund. (2019). Comparing forwarder boom-control systems based on an automatically recorded follow-up dataset. Silva Fennica vol. 53 no. 2 article id 10161. https://doi.org/10.14214/sf.10161
Highlights: Boom-tip control saves time compared to the conventional system; This study introduced a field-study design enabling establishment of causal relationships during ordinary forwarding operations; Although the study design requires some extra arrangements, it efficiently combines the representativeness of conventional follow-up datasets with establishment of causal relationships that traditionally have been possible only through observational time studies or standardized experiments.

Crane work is the most time-consuming work element in forwarding. Hence, assist systems like boom-tip control are of interest. The first commercially available boom-tip control for forwarders was introduced in 2013. In this study we analysed whether replacing conventional boom control (CBC) with John Deere’s version of boom-tip control (named Intelligent Boom Control, IBC), increases crane-work productivity. We used data automatically gathered from 10 final-felling stands, covering typical logging conditions for southern, central and northern Sweden. Two John Deere 1510E and two John Deere 1910G forwarders were operated by seven experienced operators during the follow-up study, covering 1238 loads in total. A split-plot design was applied to isolate effects of the boom-control system being used (CBC, IBC). We found that using IBC for loading work (crane work and driving included) saved 5.2% of productive machine time compared to using CBC (p ≤ 0.05). The corresponding saving when using IBC for unloading work was 7.9% (p ≤ 0.05). Depending on geophysical factors, this corresponds to approximately 4% savings in productive machine time for forwarding as a whole, including pure transport (with and without load). Moreover, the study introduced in cut-to-length context a novel field-study design to collect a large follow-up dataset in the course of ordinary forwarding operations. We found the study design to be a cost-efficient way to combine the representativeness of conventional follow-up datasets with the ability to establish causal relationships. Establishment of causal relationships has traditionally been possible only through observational time studies or standardized experiments.

  • Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID: http://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se (email)
  • Mörk, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: anders.mork@skogforsk.se
  • Englund, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: martin.englund@skogforsk.se
article id 9933, category Research article
Timo Saksa, Jari Miina, Hilkka Haatainen, Kauko Kärkkäinen. (2018). Quality of spot mounding performed by continuously advancing mounders. Silva Fennica vol. 52 no. 2 article id 9933. https://doi.org/10.14214/sf.9933
Highlights: The number and quality of mounds varied considerably according to the operating conditions;The main factors reducing the quality of spot mounding were steep terrain, a thick humus layer, fresh logging residues, stoniness and soil texture;With careful selection of timing and conditions for mounding, the quality obtained by continuously advancing mounders can be improved.

Operating conditions affecting the quality of spot mounding by Bracke continuously advancing mounders were investigated on 66 regeneration areas (124 ha) in eastern Finland. The quality of mounds was classified as suitable (good or acceptable after additional compression) or unsuitable for planting. Models were constructed for the number of suitable planting spots obtained per hectare (good and acceptable mounds), the probability of successful mounding (≥1600 planting spots ha–1) and the probability of creating a suitable mound as a function of terrain, site and soil characteristics, as well as slash conditions (removed, fresh or dry logging residues). The average number of mounds created was 1892 ± 290 mounds ha–1, of which 1398 ± 325 mounds ha–1 (74%) were classified as suitable for planting. The quality of spot mounding was reduced by steep terrain, a thick humus layer and fresh logging residues. Stoniness and soil texture also affected the number of planting spots created. Mounding after logging residues had dried increased the number of planting spots by 191 spots ha–1 compared with mounding in the presence of fresh residues. Removing residues did not significantly increase the number of planting spots compared with mounding amongst dry residues. A thick humus layer, very stony soil, steep slopes and valley terrain decreased the number of planting spots by 150–450 spots ha–1. The number and quality of mounds varied considerably according to the operating conditions, but with careful selection of timing and sites the quality obtained by a continuously advancing mounder can be improved.

  • Saksa, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: timo.saksa@luke.fi (email)
  • Miina, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID ID:E-mail: jari.miina@luke.fi
  • Haatainen, Faculty of Science and Forestry, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: hilkka.haatainen@storaenso.com
  • Kärkkäinen, Tornator Oyj, Muuntamontie 2, FI-80100 Joensuu, Finland ORCID ID:E-mail: kauko.karkkainen@tornator.fi
article id 7830, category Research article
Jari Lindblad, Johanna Routa, Johanna Ruotsalainen, Marja Kolström, Ari Isokangas, Lauri Sikanen. (2018). Weather based moisture content modelling of harvesting residues in the stand. Silva Fennica vol. 52 no. 2 article id 7830. https://doi.org/10.14214/sf.7830
Highlights: Weather data used for estimating the moisture content of energy wood; The validation of the weather based models performed based on the field data.

Harvesting residues collected from the final cuttings of boreal forests are an important source of solid biofuel for energy production in Finland and Sweden. In the Finnish supply chain, the measurement of residues is performed by scales integrated in forwarders. The mass of residues is converted to volume by conversion factors. In this study, weather based models for defining the moisture content of residues were developed and validated. Models were also compared with the currently used fixed tables of conversion factors. The change of the moisture content of residues is complex, and an exact estimation was challenging. However, the model predicting moisture change for three hour periods was found to be the most accurate. The main improvement compared to fixed tables was the lack of a systematic error. It can be assumed that weather based models will give more reliable estimates for the moisture in varying climate conditions and the further development of models should be focused on obtaining more appropriate data from varying drying conditions in different geographical and microclimatological locations.

  • Lindblad, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID ID:E-mail: jari.lindblad@luke.fi (email)
  • Routa, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID ID:E-mail: johanna.routa@luke.fi
  • Ruotsalainen, Finnish Meteorological Institute, Aviation and Military Weather Services, P.O. Box 1627, FI-70211 Kuopio, Finland ORCID ID:E-mail: johanna.ruotsalainen@fmi.fi
  • Kolström, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: marja.kolstrom@uef.fi
  • Isokangas, University of Oulu, Control Engineering, P.O. Box 8000, FI-90014 University of Oulu, Finland ORCID ID:E-mail: ari.isokangas@oulu.fi
  • Sikanen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID ID:E-mail: lauri.sikanen@luke.fi
article id 6989, category Research article
Åsa Gustafsson. (2017). Assessing work order information quality in harvesting. Silva Fennica vol. 51 no. 4 article id 6989. https://doi.org/10.14214/sf.6989
Highlights: This paper concludes that information quality with regards to accuracy in work order information components pertaining to “Landing – placement and size”, “Cleaning understory trees – not conducted and of low standard”, are lacking and need to be improved in harvesting.

Being a logging contractor involves several uncertainties, amongst others, information quality in the work order received from customers. The information quality of work orders is of the utmost importance for logging contactors, in order to be able to plan and conduct work properly. The purpose of this paper is three-fold: 1) identifying work order information components in harvesting, 2) identifying work order information quality dimensions in harvesting and 3) assessing work order information quality in harvesting. The paper is based on interviews and a survey. Various interviews took place in Sweden with professionals within the harvesting industry as well as logging contractors, and thereafter a survey was developed. Random selection was conducted and 100 Swedish logging contractors were contacted by telephone in order to answer the survey, with a response rate of 82% from the sample. The paper concludes that the information quality dimension of accuracy concerns the individual work order information components, whereas timeliness is related to receiving the complete work orders. A factor analysis has been conducted with five factors emerging. The assessment of work order information quality in harvesting implies that the potential for improvement exists with regard to increasing the accuracy of the order information for the components of “Cleaning under story trees – not conducted” and “Cleaning under story trees – of low standard” as well as “Landing – size”, and “Landing – placement”. However, their effect on capacity is utilization needs to be explored.

  • Gustafsson, Linnaeus University, School of Business and Economics, Department of Management Accounting and Logistics, 391 82 Kalmar, Sweden ORCID ID:E-mail: asa.gustafsson@lnu.se (email)
article id 1689, category Research article
Juha Laitila, Eeva Lehtonen, Tapio Ranta, Perttu Anttila, Saija Rasi, Antti Asikainen. (2016). Procurement costs of cereal straw and forest chips for biorefining in South-East Finland. Silva Fennica vol. 50 no. 5 article id 1689. https://doi.org/10.14214/sf.1689
Highlights: Procurement cost at the plant was 59 € dry tonne –1 when the annual procurement volume of biomass was 100 000 tonnes. Of that amount, the proportion of logging residues was 58.4%, stumps 24.3% and delimbed stems 17.3%; Cereal straw represents an important source of biomass in Kouvola but the cost competiveness is poor compared the procurement costs of forest chips due to high baling and transporting costs.

In Finland the increasing use of biofuel in transport presupposes a search for new raw material sources for biorefining. The aim of this study was, at the regional level, to compare the procurement costs of logging residues, stumps, delimbed stems and cereal straw for biorefining. The accumulation and procurement costs of forest chips and cereal straw were estimated within a 100-kilometre transporting distance via existing road network from an end-use-facility located in Kouvola in South-East Finland. The analyses were performed as simulated treatments in thinnings of young stands, cereal fields and regeneration fellings using existing productivity and cost functions and yield calculations based on crop statistics, the forest industry stand data and the sample plots data of the National Forest Inventory of Finland. Accumulation of raw material assortments and costs of production stages were defined per dry tonnes. Subsidies and raw material prices were excluded from consideration in the study. The results indicate that recovering logging residues requires lower costs than utilization of stumps, delimbed stems or cereal straw. Cereal straw represents an important source of biomass in Kouvola but the cost competiveness is poor compared the procurement costs of forest chips. When the annual procurement volume of biomass was 50 000 dry tonnes the cost at the plant was 49 € dry tonne –1 and biomass was comprised totally of logging residues. Procurement cost grew to 59 € dry tonne –1 when the annual procurement volume of biomass was doubled to 100 000 dry tonnes. Of that amount, the proportion of logging residues was 58.4%, stumps 24.3% and delimbed stems 17.3%. First cereal straw dry tonnes were delivered to end-use-facility, when procurement cost grew to 60 € dry tonne –1 and annual procurement volume of biomass was 110 000 dry tonnes.

  • Laitila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@luke.fi (email)
  • Lehtonen, Natural Resources Institute Finland (Luke), Green Technology, Halolantie 31A, FI-71750 Maaninka, Finland ORCID ID:E-mail: eeva.lehtonen@luke.fi
  • Ranta, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@luke.fi
  • Anttila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: perttu.anttila@luke.fi
  • Rasi, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, Survontie 9A, FI-40500 Jyväskylä ORCID ID:E-mail: saija.rasi@luke.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.asikainen@luke.fi
article id 1546, category Research article
Jussi Manner, Lauri Palmroth, Tomas Nordfjell, Ola Lindroos. (2016). Load level forwarding work element analysis based on automatic follow-up data. Silva Fennica vol. 50 no. 3 article id 1546. https://doi.org/10.14214/sf.1546
Highlights: Recent developments in on-board technology enables automatic collection of follow-up data on forwarder work; Time consumption per load was more strongly associated with Loading drive distance than with extraction distance, indicating that the relevance of extraction distance as a main indicator of forwarding productivity should be re-considered; Data, within variables, were positively skewed with a few exceptions with normal distributions.

Recent developments in on-board technology have enabled automatic collection of follow-up data on forwarder work. The objective of this study was to exploit this possibility to obtain highly representative information on time consumption of specific work elements (including overlapping crane work and driving), with one load as unit of observation, for large forwarders in final felling operations. The data used were collected by the John Deere TimberLink system as nine operators forwarded 8868 loads, in total, at sites in mid-Sweden. Load-sizes were not available. For the average and median extraction distances (219 and 174 m, respectively), Loading, Unloading, Driving empty, Driving loaded and Other time effective work (PM) accounted for ca. 45, 19, 8.5, 7.5 and 14% of total forwarding time consumption, respectively. The average and median total time consumptions were 45.8 and 42.1 minutes/load, respectively. The developed models explained large proportions of the variation of time consumption for the work elements Driving empty and Driving loaded, but minor proportions for the work elements Loading and Unloading. Based on the means, the crane was used during 74.8% of Loading PM time, the driving speed was nonzero during 31.9% of the Loading PM time, and Simultaneous crane work and driving occurred during 6.7% of the Loading PM time. Time consumption per load was more strongly associated with Loading drive distance than with extraction distance, indicating that the relevance of extraction distance as a main indicator of forwarding productivity should be re-considered.

  • Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: jussi.manner@skogforsk.se (email)
  • Palmroth, John Deere Forestry, P.O. Box 472, FI-33101 Tampere, Finland ORCID ID:E-mail: PalmrothLauri@JohnDeere.com
  • Nordfjell, Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: tomas.nordfjell@slu.se
  • Lindroos, Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: ola.lindroos@slu.se
article id 1448, category Research article
Andrew McEwan, Natascia Magagnotti, Raffaele Spinelli. (2016). The effects of number of stems per stool on cutting productivity in coppiced Eucalyptus plantations. Silva Fennica vol. 50 no. 2 article id 1448. https://doi.org/10.14214/sf.1448
Highlights: Double- and single stem coppice stools were harvested mechanically; Stem size had the strongest impact on productivity; An experienced operator performed equally well with both stool treatments; Cost was ~10% higher with double stems for the less experienced operator; Operator experience may play a major role when cutting coppice stands.

A time study was conducted to determine whether stem crowding had any impact on harvester productivity in Eucalyptus grandis stands. This represents an important element when trying to balance the advantages and disadvantages of coppice management in fast growing plantations designated for mechanized harvesting (i.e. machine felling, delimbing, debarking and cross-cutting). The study material consisted of 446 coppice stems, half of which grew as single stems per stool and half as double stems per stool as a result of different coppice reduction strategies. The dataset was balanced and randomized, with both subsets replicating exactly the same stem size distribution and the single and double stems alternating randomly. Harvester productivity ranged between 6 and 50 m3 under bark per productive machine hour, following the variation of tree diameter from 10 to 40 cm at breast height (1.37 m according to South African standards). Regression analysis indicated that both tree size and stem crowding (e.g. one or two stems per stool) had a significant effect on harvester productivity, which increased with stem size and decreased with stem crowding. However, operator experience may overcome the effect of stem crowding, which was not significant when the harvester was manned by a highly experienced operator. In any case, the effect of stem size was much greater than that of stem crowding, which resulted in a cost difference of less than 10%. However, this figure excludes the possible effects of stem crowding on volume recovery and stem development, which should be addressed in the future.

  • McEwan, Nelson Mandela Metropolitan University – George Campus, Saasveld, 6529, George, South Africa ORCID ID:E-mail: Andrew.McEwan@nmmu.ac.za
  • Magagnotti, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (FI), Italy ORCID ID:E-mail: magagnotti@ivalsa.cnr.it
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (FI), Italy ORCID ID:E-mail: spinelli@ivalsa.cnr.it (email)
article id 1003, category Research article
Raffaele Spinelli, Carolina Lombardini, Natascia Magagnotti. (2014). The effect of mechanization level and harvesting system on the thinning cost of Mediterranean softwood plantations. Silva Fennica vol. 48 no. 1 article id 1003. https://doi.org/10.14214/sf.1003
Highlights: Whole-tree harvesting is 40–50% cheaper than cut-to-length harvesting; Mechanization reduced thinning cost by a factor 4; Between 1.5 and 6% of the residual trees were damaged; Mechanized cut-to-length harvesting allows controlled biomass release; Mechanized whole-tree harvesting is the cheapest option for energy chip production.
The study compared motor-manual cut-to-length (CTL) harvesting, motor-manual whole-tree (WT) harvesting, mechanized CTL harvesting and mechanized WT harvesting as applied to the production of energy chips from the second thinning of Mediterranean pine plantations in flat terrain. Mechanization increased productivity between 6 and 20 times, depending on process step. It also allowed reducing thinning cost by a factor 4. Shifting from CTL to WT harvesting resulted in a reduction of harvesting cost between 40 and 50%. Fuel consumption was between 40 and 100% higher for CTL harvesting than for WT harvesting. Mechanization entailed a reduction of fuel consumption between 10 and 40%. Stand damage was generally low, between 1.5 and 6%. Mechanized CTL harvesting resulted in the lowest incidence of wounding, and the difference between mechanized CTL and manual WT harvesting was statistically significant. Soil compaction was absent or very small, depending on treatment. Mechanized thinning may produce larger increases of soil bulk density, compared to motor-manual thinning, but the difference is small, although significant. CTL harvesting leaves a larger amount of biomass on the soil, which relieves possible concerns about soil nutrient depletion. On the other hand, heavy residue loads may increase fire risk especially in sensitive Mediterranean environments.
  • Spinelli, CNR IVALSA,Via Madonna del Piano 10, Sesto Fiorentino (FI), Italy ORCID ID:E-mail: spinelli@ivalsa.cnr.it (email)
  • Lombardini, CNR IVALSA,Via Madonna del Piano 10, Sesto Fiorentino (FI), Italy ORCID ID:E-mail: lombardini@ivalsa.cnr.it
  • Magagnotti, CNR IVALSA,Via Biasi 75, S. Michele all’Adige (TN), Italy ORCID ID:E-mail: magagnotti@ivalsa.cnr.it
article id 949, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Erlend Rolstad. (2014). Effects of logging on the threatened epiphytic lichen Usnea longissima: an experimental approach. Silva Fennica vol. 48 no. 1 article id 949. https://doi.org/10.14214/sf.949
Highlights: A re-inventory of the threatened lichen Usnea longissima in ten Norway spruce forest stands where experimental selective loggings had been conducted 5 to 8 years before revealed that the number of lichen thalli had increased with 34%; The number of thalli increased more where the forest was open whether or not the low tree density was caused by the loggings.
Usnea longissima Ach. is a circumboreal epiphytic lichen draping tree canopies in moist coastal and mountainous forests. It is extinct from many European and North-American localities, presumably due to industrial forestry and air pollution, but still has a stronghold in parts of Scandinavia and U.S. and Canadian Pacific Northwest. In 2005/06 we used a comparative and retrospective approach to evaluate how present and historic tree and stand characteristics influenced the occurrence and abundance of the lichen (Storaunet et al. 2008). In 2012, we re-inventoried ten Norway spruce forest stands with 401 U. longissima-bearing trees and recorded changes in the number of U. longissima thalli. Seven of the stands had been experimentally, selectively logged 5–8 years before, where the lichen-bearing trees had been marked in the field and were avoided during the logging operation. Total number of lichen-bearing trees decreased slightly (2.9%), whereas the number of thalli had increased with 34%. Number of thalli increased more where the forest was open (low basal area, m2ha-1) whether or not the low tree density was caused by the logging events. At high tree densities the change in number of thalli was negligible. We suggest that selective logging, securing lichen-bearing trees, may be a viable management option to keep tree density from becoming too dense, thereby enhancing growth and establishment of U. longissima.
  • Storaunet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: stk@skogoglandskap.no (email)
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: roj@skogoglandskap.no
  • Rolstad, Skogfaglig Rådgivning, Holmsida 126, NO-1488 Hakadal, Norway ORCID ID:E-mail: roe@skogoglandskap.no
article id 1030, category Research article
Jussi Manner, Tomas Nordfjell, Ola Lindroos. (2013). Effects of the number of assortments and log concentration on time consumption for forwarding. Silva Fennica vol. 47 no. 4 article id 1030. https://doi.org/10.14214/sf.1030
Highlights: We analysed the effects of total and forwarded log concentrations (m3 (100 m)–1) and the number of loaded assortments on forwarding; The combination of the number of loaded assortments and their abundance (i.e. forwarded log concentration) affected time consumption most; This knowledge enables improved efficiency by optimizing number and assortment proportions in the various loads required to forward a stand.
Forwarding has been carried out for 50 years, but much is still unknown about this work. Its complexity comes from both stand features and essential decision-making. Forwarding time consumption is influenced by e.g. log concentrations and number of assortments. Traditionally, focus has been on the total log concentration (TLC), referring to all logs at the harvesting site. However, we focused on forwarded log concentration (FLC), the load-specific log concentration which depends on the assortment distribution at harvesting site and the load-specific number of assortments. To evaluate the effects of TLC, number of assortments in a load and FLC on the loading and unloading times, a standardized field experiment was carried out. Pile and load sizes were constant, while TLC and FLC were manipulated by varying the pile distribution on the test path. For all work elements, the time consumption per m3 was significantly affected by the number of assortments that were loaded, but only the “driving while loading” work element was also significantly influenced by TLC. However, when untangling the intercorrelation between tested factors, it was found that the time consumption for driving while loading significantly decreased as a function of FLC and was unaffected by the number of assortments in a load. That FLC influences the forwarding time consumption highlights the need to study the effects of combining various assortment proportions in a load. Such knowledge will enable analysis of the most efficient number and assortment proportions to combine in the various loads required to forward a given stand.
  • Manner, Swedish University of Agricultural Sciences, Department of Forest Biomaterial and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: jussi.manner@slu.se (email)
  • Nordfjell, Swedish University of Agricultural Sciences, Department of Forest Biomaterial and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: tomas.nordfjell@slu.se
  • Lindroos, Swedish University of Agricultural Sciences, Department of Forest Biomaterial and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: ola.lindroos@slu.se
article id 1022, category Research article
Eero Muinonen, Perttu Anttila, Jaakko Heinonen, Jukka Mustonen. (2013). Estimating the bioenergy potential of forest chips from final fellings in Central Finland based on biomass maps and spatially explicit constraints. Silva Fennica vol. 47 no. 4 article id 1022. https://doi.org/10.14214/sf.1022
The technical potential of forest chips from final fellings in Central Finland was estimated using a method based on biomass maps derived from a multi-source forest inventory technique. Image segmentation techniques were applied to a satellite image mosaic to detect stand boundaries. The technical potential of forest chips was computed based on primary forestry residues, i.e. logging residues and stumps from final fellings. Harvesting level definitions for final fellings were established using realized statistics for roundwood at the municipality level as well as larger area statistics. The sensitivity of the potential to ecological and technical constraints in the model was also examined. The technical recovery rate of stump harvesting according to biomass harvesting guidelines was evaluated separately. The critical prerequisites for using the advanced, spatially explicit approach to analysing forest energy potentials may lie in the existence of spatially explicit forest inventory data and the biometric models for tree biomass assortments. The method applied was capable of taking into account the constraints that rely upon map data, such the actual forwarding distance or steepness of the slope in the terrain. The calculation results can be used for strategic decision making in the field of forest bioenergy production.
  • Muinonen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: eero.muinonen@metla.fi (email)
  • Anttila, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: perttu.anttila@metla.fi
  • Heinonen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: jaakko.heinonen@metla.fi
  • Mustonen, Stora Enso, Talvikkitie 40 C, FI-01300 Vantaa, Finland ORCID ID:E-mail: jukka.mustonen@storaenso.com
article id 993, category Research article
Jori Uusitalo, Jari Ala-Ilomäki. (2013). The significance of above-ground biomass, moisture content and mechanical properties of peat layer on the bearing capacity of ditched pine bogs. Silva Fennica vol. 47 no. 3 article id 993. https://doi.org/10.14214/sf.993
Intensive utilisation of peatland forests calls for logging activities to be increasingly carried out in conditions other than those in harsh winter. The low bearing capacity of peatlands forms a severe obstacle for the prevailing harvesting machinery. The aim of this study was to clarify and quantify the significance of above-ground biomass, brash mat, moisture content and mechanical properties of peat layer on the bearing capacity of pine bogs. In-situ driving tests were conducted in Western Finland on a pine bog covering a large variation of growing stock. Portable tools were tested for measuring strength properties of the top layer of peat. According to the results, shear modulus of top layer of peat, volume of trees and the existence of cutting debris are the most important factors affecting bearing capacity. Spiked shear vane was shown to be a promising tool in predicting the strength properties of peat soil.
  • Uusitalo, Finnish Forest Research Institute, Parkano Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: jori.uusitalo@metla.fi (email)
  • Ala-Ilomäki, Finnish Forest Research Institute, Vantaa Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: jari.ala-ilomaki@metla.fi
article id 933, category Research article
Per-Ola Hedwall, Harald Grip, Sune Linder, Lars Lövdahl, Urban Nilsson, Johan Bergh. (2013). Effects of clear-cutting and slash removal on soil water chemistry and forest-floor vegetation in a nutrient optimised Norway spruce stand. Silva Fennica vol. 47 no. 2 article id 933. https://doi.org/10.14214/sf.933
Fertilisation with nutrient optimisation has in Sweden resulted in large increases in volume growth in young stands of Norway spruce. There are, however, environmental concerns about repeated fertilisation and one is the risk of nutrient leakage to ground water resources and aquatic ecosystems after clear-cutting of such forests. The present study followed soil-water chemistry in optimised fertilised stands after clear-cutting, as well as effects of harvest of slash on nutrient leakage. Parts of a 30-year-old stand of Norway spruce, which had been subject to a nutrient optimisation experiment for 17 years, were clear-cut. A split-plot design with whole-tree harvesting as the sub-plot treatment was applied. Lysimeters were installed and soil-water sampled at nine occasions during the following four years. No significant effects of fertilisation on nitrate leaching were found, while harvest of slash reduced the concentration of Ca, DOC, DON, K, Mg, ammonium and nitrate, as well as pH in the soil solution. While no effects of fertilisation could be seen on the soil water concentration of N, the results indicate an interaction between fertilisation and harvest of slash on the concentration of nitrate in the soil solution. The results indicate that forest-floor vegetation plays an important role in the retention of N after clear-cutting of fertilised forests.
  • Hedwall, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: per-ola.hedwall@slu.se (email)
  • Grip, Department of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail: harald@grip2.se
  • Linder, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: sune.linder@slu.se
  • Lövdahl, Department of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail:
  • Nilsson, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: urban.nilsson@slu.se
  • Bergh, Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences (SLU), P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: johan.bergh@slu.se
article id 67, category Research article
Pentti Niemistö, Heikki Korpunen, Ari Laurén, Marika Salomäki, Jori Uusitalo. (2012). Impact and productivity of harvesting while retaining young understorey spruces in final cutting of downy birch (Betula pubescens). Silva Fennica vol. 46 no. 1 article id 67. https://doi.org/10.14214/sf.67
Quite often Norway spruce (Picea abies (L.) Karsten) forms an understorey in birch dominated stands in Finland. Advantageous growth conditions for both storeys are present especially in downy birch (Betula pubescens Ehrh.) stands on drained fertile peatland. The most common way of regenerating mature Downy birch forest is clear cutting and replanting with Norway spruce, even if vital spruce seedlings or saplings was already growing under the birch. The aim of this study is to investigate the impact of retaining young understorey spruces on the productivity of harvesting and on the quality of the remaining stands in downy birch dominated stands with modern cut-to-length (CTL) machinery. Retaining undergrowth spruces decreased productivity of cutting in managed stands (600 stems/ha) by 6–9 per cent and in unmanaged stands (1200 stems/ha) by 11–17 per cent compared with clear cutting, where the understorey is not considered. Compared with the case where no understorey was present, the decrease in productivity was 10–17 per cent and 21–30 per cent respectively. In forwarding, retaining the undergrowth decreased the productivity of loading phases by 7–14 per cent. Harvesting treatment where spruces were retained produced an adequate stand structure for the future growing stock. Using this method, 14–24 per cent of the original spruces were totally destroyed while 25–44 per cent of spruces were destroyed when they were not considered for harvesting. The spatial variation of the remaining spruces was much better in the treatment where spruces were retained. Our study results shows that in this kind of two storey birch–spruce forests, the harvesting treatment where spruces are retained while cutting is the most acceptable and profitable method. It allows for a vital spruce sapling to continue growing, and avoids regeneration and tending costs or other harmful effects of clear-cut areas such as the freezing of young spruce plants and an increase in the ground water table.
  • Niemistö, Finnish Forest Research Institute, Parkano & Joensuu, Finland ORCID ID:E-mail:
  • Korpunen, Finnish Forest Research Institute, Parkano & Joensuu, Finland ORCID ID:E-mail:
  • Laurén, Finnish Forest Research Institute, Parkano & Joensuu, Finland ORCID ID:E-mail:
  • Salomäki, Finnish Forest Research Institute, Parkano & Joensuu, Finland ORCID ID:E-mail:
  • Uusitalo, Finnish Forest Research Institute, Parkano & Joensuu, Finland ORCID ID:E-mail: jori.uusitalo@metla.fi (email)
article id 122, category Research article
Benoit Lafleur, Nicole J. Fenton, David Paré, Martin Simard, Yves Bergeron. (2010). Contrasting effects of season and method of harvest on soil properties and the growth of black spruce regeneration in the boreal forested peatlands of eastern Canada. Silva Fennica vol. 44 no. 5 article id 122. https://doi.org/10.14214/sf.122
It has been suggested that without sufficient soil disturbance, harvest in boreal forested peatlands may accelerate paludification and reduce forest productivity. The objectives of this study were to compare the effects of harvest methods (clearcutting vs. careful logging) and season (summer vs. winter harvest) on black spruce regeneration and growth in boreal forested peatlands of eastern Canada, and to identify the soil variables that favour tree growth following harvest. Moreover, we sought to determine how stand growth following harvest compared with that observed following fire. The average tree height of summer clearcuts was greater than that of summer carefully logged stands and that of all winter harvested sites. Summer clearcutting also resulted in a higher density of trees > 3 m and > 4 m tall and in a 50% reduction in Rhododendron groenlandicum cover, a species associated with reduced black spruce growth. Height growth of sample trees was related to foliar N and P concentrations, and to soil total N, pH and available Ca and Mg but not to harvest method or season. Our results also indicate that summer clearcutting could produce stand productivity levels comparable to those observed after high-severity soil burns. These results suggest that summer clearcutting could be used to restore forest productivity following harvest in forested peatlands, and offer further support to the idea that sufficient levels of soil disturbance may be required to restore productivity in ecosystems undergoing paludification.
  • Lafleur, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada ORCID ID:E-mail: benoit.lafleur@uqat.ca (email)
  • Fenton, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada ORCID ID:E-mail:
  • Paré, Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, QC G1V 4C7, Canada ORCID ID:E-mail:
  • Simard, Département de Géographie, Université Laval, Pavillon Abitibi-Price, 2405 rue de la Terrasse, Québec, QC G1V 0A6, Canada ORCID ID:E-mail:
  • Bergeron, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada ORCID ID:E-mail:
article id 162, category Research article
Ruut Rabinowitsch-Jokinen, Ilkka Vanha-Majamaa. (2010). Immediate effects of logging, mounding and removal of logging residues and stumps on coarse woody debris in managed boreal Norway spruce stands. Silva Fennica vol. 44 no. 1 article id 162. https://doi.org/10.14214/sf.162
Wood fuel production has increased remarkably, but its environmental effects within the forest ecosystem have not yet been studied much. We investigated the immediate effects of two series of forest management treatments, which produce timber and forest chips, on the volume and decay classes of coarse woody debris (CWD). One of the treatment series included logging and residue harvesting (LRH) and mounding (M), while the other series included LRH and mounding combined with stump harvesting (MSH). We hypothesized that, i) LRH reduces CWD, excluding stumps; ii) the more intense the soil preparation treatment is, M vs. MSH, the more CWD is destroyed; iii) both LRH and soil preparation treatments (M and MSH) reduce the occurence of snags, highly decayed CWD and deciduous CWD in particular. Ten sample plots in mature managed Norway spruce (Picea abies (L.) H. Karst.) dominated forests were located in Southern Finland. The total volume of CWD on the sample plots was measured three times: before and after LRH, and after M or MSH. LRH significantly decreased the volume of snags and the combined volume of snags and logs. MSH significantly decreased the total volume of CWD, while M had no significant effect on the volume of CWD. The middle and highly decayed CWD were destroyed most easily in the treatments.
  • Rabinowitsch-Jokinen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301, Vantaa, Finland ORCID ID:E-mail:
  • Vanha-Majamaa, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301, Vantaa, Finland ORCID ID:E-mail: ilkka.vanha-majamaa@metla.fi (email)
article id 465, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Målfrid Toeneiet, Erlend Rolstad. (2008). Effect of logging on the threatened epiphytic lichen Usnea longissima: a comparative and retrospective approach. Silva Fennica vol. 42 no. 5 article id 465. https://doi.org/10.14214/sf.465
Usnea longissima is a conspicuous circumboreal “beard lichen” draping tree canopies in moist coastal and mountainous forests. It is extirpated in many European and North-American localities, presumably due to industrial forestry and air pollution, but still has a stronghold in parts of Scandinavia and U.S. and Canadian Pacific Northwest. Using a retrospective approach, we reconstructed the stand histories in 24 plots (0.1 ha) of mature Norway spruce (Picea abies) forest stands in Lillehammer, Norway, of which 21 was selected due to the presence of U. longissima. Number of trees with U. longissima present within plots varied from 4 to 37 and number of visible thalli from 12 to 469. The detailed stand reconstructions were done by means of tree-ring analysis of 517 living trees and the size and decay stage of 1423 stumps from logging and 467 dead trees. Total harvested volume during the last 100 years ranged 100–370 m3ha–1 (representing 40–350% of the present-day standing volume), and present amount of dead wood ranged 2–87 m3ha–1 (1.0–37% of the standing volume). All stands had been selectively logged 2–4 times during the last 100 years, of which 5 stands almost to a clearcut appearance. We used a variety of present-day and historic forest structural variables, both at the scale of study plots and individual trees, to predict the occurrence and abundance of U. longissima. Although most forest stand variables failed in this respect, there were indications of a certain negative influence of the historic logging activity. Number of thalli present on trees showed a unimodal relationship to present-day tree density, indicating that medium dense forest stands are most favorable for U. longissima. We tentatively suggest that selective logging, securing lichen-rich trees, may be a viable management option to keep tree density at a moderate level in the long run, thereby enhancing growth and establishment of U. longissima.
  • Storaunet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: ken.storaunet@skogoglandskap.no (email)
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
  • Toeneiet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
article id 465, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Målfrid Toeneiet, Erlend Rolstad. (2008). Effect of logging on the threatened epiphytic lichen Usnea longissima: a comparative and retrospective approach. Silva Fennica vol. 42 no. 5 article id 465. https://doi.org/10.14214/sf.465
Usnea longissima is a conspicuous circumboreal “beard lichen” draping tree canopies in moist coastal and mountainous forests. It is extirpated in many European and North-American localities, presumably due to industrial forestry and air pollution, but still has a stronghold in parts of Scandinavia and U.S. and Canadian Pacific Northwest. Using a retrospective approach, we reconstructed the stand histories in 24 plots (0.1 ha) of mature Norway spruce (Picea abies) forest stands in Lillehammer, Norway, of which 21 was selected due to the presence of U. longissima. Number of trees with U. longissima present within plots varied from 4 to 37 and number of visible thalli from 12 to 469. The detailed stand reconstructions were done by means of tree-ring analysis of 517 living trees and the size and decay stage of 1423 stumps from logging and 467 dead trees. Total harvested volume during the last 100 years ranged 100–370 m3ha–1 (representing 40–350% of the present-day standing volume), and present amount of dead wood ranged 2–87 m3ha–1 (1.0–37% of the standing volume). All stands had been selectively logged 2–4 times during the last 100 years, of which 5 stands almost to a clearcut appearance. We used a variety of present-day and historic forest structural variables, both at the scale of study plots and individual trees, to predict the occurrence and abundance of U. longissima. Although most forest stand variables failed in this respect, there were indications of a certain negative influence of the historic logging activity. Number of thalli present on trees showed a unimodal relationship to present-day tree density, indicating that medium dense forest stands are most favorable for U. longissima. We tentatively suggest that selective logging, securing lichen-rich trees, may be a viable management option to keep tree density at a moderate level in the long run, thereby enhancing growth and establishment of U. longissima.
  • Storaunet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: ken.storaunet@skogoglandskap.no (email)
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
  • Toeneiet, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
  • Rolstad, Norwegian Forest and Landscape Institute, P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail:
article id 256, category Research article
Juha Laitila. (2008). Harvesting technology and the cost of fuel chips from early thinnings. Silva Fennica vol. 42 no. 2 article id 256. https://doi.org/10.14214/sf.256
This study compared and analyzed the procurement cost of whole tree chips when using supply chains based on comminution at the roadside landing or at the terminal. It also identified the bottlenecks of the most common logging systems used in Finland. The study was done by using existing and published productivity parameters and models. The procurement cost calculations were made for a stand where the forwarding distance was 200 metres, removal of whole trees was 60 m per hectare and the area of the stand was 2.0 hectares. The average size of the removed whole trees was 30 litres. The direct transport distance from the stand to the terminal or to the end use facility was 40 km while the secondary distance from the terminal to the end use facility was 10 km. A stumpage price for the harvested raw material was not included in this study. According to the study the cost of whole trees chips were 31.9–41.6 euros/m at the plant, or 14.9–19.4 euros/MWh when the moisture content of chips was estimated to be 40%. The two-machine system was found to be the most cost competitive logging system in pre-commercial thinnings thanks to both efficient cutting and, especially, forwarding work. In the manual worker based logging, the costs of felling bunching were the same as the mechanised system, whereas in forwarding the costs were almost double. Using the harwarder system the logging costs were found to be the highest, but in the larger tree volumes and removals the costs were almost equal to the manual worker based logging. The supply chain based on chipping at the roadside landing was more cost efficient compared to the chipping at the terminal system. The lower comminution cost at the terminal was not enough to cover the higher transportation cost of unprocessed material to the terminal, handling cost of chips at the terminal or the delivery cost to the end use facility.
  • Laitila, Finnish Forest Research Institute, Joensuu Research Unit, Joensuu, Finland ORCID ID:E-mail: juha.laitila@metla.fi (email)
article id 479, category Research article
Ken Olaf Storaunet, Jørund Rolstad, Ivar Gjerde, Vegard S. Gundersen. (2005). Historical logging, productivity, and structural characteristics of boreal coniferous forests in Norway. Silva Fennica vol. 39 no. 3 article id 479. https://doi.org/10.14214/sf.479
Conservation of forest biodiversity has brought about an interest in evaluating the naturalness of forests, and to locate and protect semi-natural and old-growth forests in the Fennoscandian countries. However, it is not always clear how natural these forests really are, and how the past management history has affected their present structural composition. We studied the relationships between cut stumps from historical logging activity (50–100 years ago) and forest structural characteristics of today in a total of 385 0.25 ha plots in three boreal coniferous forests which are parts of National Nature Reserves in Norway. We also studied how forest productivity influenced these relationships. In plots with negligible logging impact we found the amount of living trees, dead wood, and size of the oldest trees mainly to increase with increasing productivity, whereas the age of the oldest trees decreased. The amount of deciduous trees was generally low irrespective of productivity. The intensity of logging did not consistently influence most of these forest structural variables, neither at low- nor at high-productive sites. The only consistent relationship in all study areas was a decreasing amount of dead wood with increasing logging intensity at high-productive sites. Also, the decay class distribution of dead wood was more right-skewed (indicating on-going accumulation of dead wood) the more logging had occurred at high-productive sites. Except from the effects on dead wood, previous logging does not show up as a major determinant of other stand structures of today.
  • Storaunet, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway ORCID ID:E-mail: ken.storaunet@skogforsk.no (email)
  • Rolstad, Norwegian Forest Research Institute, Høgskolevegen 8, NO-1432 Ås, Norway ORCID ID:E-mail:
  • Gjerde, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway ORCID ID:E-mail:
  • Gundersen, Norwegian Forest Research Institute, Fanaflaten 4, NO-5244 Fana, Norway ORCID ID:E-mail:
article id 417, category Research article
Jori Uusitalo, Sampsa Kokko, Veli-Pekka Kivinen. (2004). The effect of two bucking methods on Scots pine lumber quality. Silva Fennica vol. 38 no. 3 article id 417. https://doi.org/10.14214/sf.417
Modern harvesters are equipped with measurement and bucking optimization systems able not only to continuously measure the length and diameter of the stem but also to predict the profile of the unknown part of a stem and to calculate the optimal cross-cutting points for the whole stem. So far, tree-bucking optimization in the Nordic countries has been efficiently applied only with spruce because the quality of pine and birch varies much more both within a stem and between stems. Since limitations in the measuring equipment mean that the presence and position of grade limits as well as additional defects in the stem will normally have to be detected and estimated manually. Consequently, optimization works inefficiently because the harvester operator is continuously forced to disregard the cutting suggestions supplied by the harvester’s automatic system. This paper presents the outcome of research intended to define how change from the current quality bucking principle to automatic bucking affects lumber quality. The study is based on field experiments and test sawing data on 100 Scots pine (Pinus sylvestris) stems from southwestern Finland in 2001. Automatic bucking does not markedly lower the amount of good-quality lumber compared to quality bucking. Since automatic bucking inevitably leads to log distribution that matches the length requirements of customers better, it may be regarded as appropriate for these harvesting conditions.
  • Uusitalo, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: jori.uusitalo@joensuu.fi (email)
  • Kokko, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail:
  • Kivinen, University of Helsinki, Department of Forest Resource Management, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail:
article id 566, category Research article
Philip J. Burton. (2002). Effects of clearcut edges on trees in the sub-boreal spruce zone of Northwest-Central British Columbia. Silva Fennica vol. 36 no. 1 article id 566. https://doi.org/10.14214/sf.566
Clearcut-forest boundaries were evaluated for their effects on mature and regenerating trees in the northern interior of British Columbia, Canada. Two hundred and eighteen rectangular plots measuring 200 m2 each were arrayed in transects across 12 cutblock edges created 9 to 21 years earlier, with the wall of standing timber facing either north or south. The density of canopy trees on the inner edge was found to be reduced by 19% (on north-facing edges) to 46% (on south-facing edges) from average densities found in forest interiors. This reduction was primarily due to windthrow after logging, which was elevated by 27% (over interior background levels) at north-facing edges, and by 216% at south-facing edges. Of the trees situated within 10 m of south-facing cutblock edges, 11% of the Pinus contorta, 18% of the Abies lasiocarpa, and 42% of the Picea engelmannii x glauca trees have apparently collapsed, primarily those having height-to-dbh ratios greater than 71:1. As a result, irradiance in the forest understory was elevated (over interior levels) at south-facing edges to distances of approximately 65 to 70 m into the forest. Increased irradiance from adjacent cutblocks enhanced the understory growth of Picea for approximately 60 m into the inner edge of forests, 75 m for Abies. Mature Pinus trees on south-facing edges showed an unexplained 48% decrease in radial growth compared to average growth rates in forest interiors, an effect that was detectable up to 45 m into the forest. Elevated densities of conifer seedlings were evident for up to approximately 70 m into clearcuts from north-facing forest edges. Seedling growth in clearcuts was largely unaffected by shade from stand edges. Though the extent of edge effects varies considerably with the statistical techniques used to detect them, it appears that opening effects on trees can extend between 40 and 120 m into this forest type, while canopy effects reach shorter distances into clearcuts.
  • Burton, Symbios Research and Restoration, P.O. Box 3398, 3868 13th Avenue, Smithers, British Columbia, Canada V0J 2N0 ORCID ID:E-mail: symbios@bulkley.net (email)
article id 604, category Research article
Dan Glöde, Ulf Sikström. (2001). Two felling methods in final cutting of shelterwood, single-grip harvester productivity and damage to the regeneration. Silva Fennica vol. 35 no. 1 article id 604. https://doi.org/10.14214/sf.604
In order to find an efficient and careful way of final-cutting shelterwoods, two felling methods, in a single-grip harvester system, were compared with respect to productivity and damage caused to the regeneration. The shelterwood (140–165 m3/ha) consisted of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) and the natural regeneration (9530–11 780 seedlings/ha) mostly of Norway spruce. Treatments were: (i) conventional felling on both sides of the harvester striproad, preferably in blanks of the regeneration; (ii) felling of the trees top-end first into the striproad using a method named “tossing the caber”. Both treatments included forwarding after felling. Conventional felling had a non-significantly higher productivity (27.4 m3/E15–h) and lower cost (25.9 SEK/m3) than tossing the caber (26.1 m3/E15–h and 27.2 SEK/m3). However, tossing the caber was significantly more efficient in the felling and processing of pine trees compared with conventional felling. The mean proportions of the disappeared and damaged seedlings were approximately 40% after both treatments. The logging-related damage to the regeneration decreased with increased distance to the striproad in the tossing the caber treatment but not in conventional felling. The conclusions were that there were no differences between the treatments regarding productivity, cost and total damage to the regeneration in mixed conifer shelterwoods but that tossing the caber could be a more productive method than conventional felling in pine dominated stands. Tossing the caber could also be beneficial at a regeneration height of 2–3 m since at this height the damage to the regeneration seems less than at conventional felling.
  • Glöde, SkogForsk, Uppsala Science Park, S-751 83 Uppsala, Sweden ORCID ID:E-mail: dan.glode@skogforsk.se (email)
  • Sikström, SkogForsk, Uppsala Science Park, S-751 83 Uppsala, Sweden ORCID ID:E-mail:
article id 642, category Research article
Jonas Rönnberg. (2000). Logging operation damage to roots of clear-felled Picea abies and subsequent spore infection by Heterobasidion annosum. Silva Fennica vol. 34 no. 1 article id 642. https://doi.org/10.14214/sf.642
Two studies were carried out to examine the effects of clear-felling operations on stump roots of Norway spruce (Picea abies (L.) Karst.). In study I, the number of cases and the degree of damage to stump roots of Norway spruce were investigated on three clear-felled sites in northern and southern Sweden respectively. The cutting was done in winter or spring. A mean of 37% of the stumps had signs of root damage caused by clear-felling operations. Study II was carried out on two sites in southern and two sites in northern Sweden. The trees were clear-felled in June or July. The frequency of natural infection by Heterobasidion annosum (Fr.) Bref. through damaged roots was compared to infection through stump surfaces. The total area of damage on roots was 88% of the stump surface area. On average, 54% of the stumps were infected through the stump surface and 19% through locations of root damage. The root infections, however, were generally small in size as compared to stump surface infections. The study shows that damage to roots at clear-felling may be extensive, but this probably is not of great importance for the efficacy of stump treatment against H. annosum.
  • Rönnberg, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: jonas.ronnberg@ess.slu.se (email)

Category: Research note

article id 1717, category Research note
Jussi Manner, Olle Gelin, Anders Mörk, Martin Englund. (2017). Forwarder crane’s boom tip control system and beginner-level operators. Silva Fennica vol. 51 no. 2 article id 1717. https://doi.org/10.14214/sf.1717
Highlights: Boom tip control (BTC) allows the operator to control boom tip movements directly, instead of controlling each movement separately to achieve the desired boom tip movement; BTC eased boom control, so beginner-level operators using BTC achieved higher productivity than beginner-level operators using a conventional (reference) system; There were no significant differences in the slopes of learning curves between the systems.

The forwarder loads processed wood and transports it to a landing. Productivity of forwarding could be improved by increasing driving speed, but difficult forest terrain limits this. According to current literature, crane work is the most time-consuming work element of forwarding, so improving crane work productivity is essential for improving forwarding productivity. One way to do this is through automation of recurrent boom movement patterns, or alternatively automation can be used to ease crane work. When using conventional boom control (CBC), the operator manually controls each of the independent boom joint movements and combines them to achieve a desired boom tip movement, but boom tip control (BTC) allows the operator to control boom tip movements directly. The objective of the present study was to examine whether BTC facilitates crane work and affects the slopes of learning curves for beginner-level forwarder operators. The study was carried out using a standardised test routine to evaluate effects of two fixed factors, system (levels: CBC, BTC) and point of time (four levels), on five dependent variables. Four of the five dependent variables measured ease of boom control and the fifth measured crane work productivity. The results showed that there were no significant differences in the slopes of learning curves between the systems but the BTC did increase crane work productivity and made boom control easier.

  • Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID: http://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se (email)
  • Gelin, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: olle.gelin@skogforsk.se
  • Mörk, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: anders.mork@skogforsk.se
  • Englund, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: martin.englund@skogforsk.se
article id 442, category Research note
Emil Modig, Bo Magnusson, Erik Valinger, Jonas Cedergren, Lars Lundqvist. (2012). Damage to residual stand caused by mechanized selection harvest in uneven-aged Picea abies dominated stands. Silva Fennica vol. 46 no. 2 article id 442. https://doi.org/10.14214/sf.442
Permanent field plots were established in two uneven-aged Norway spruce (Picea abies (L.) Karst) dominated stands in west-central Sweden. The objective was to quantify level and type of damage caused by harvesting and to quantify the difference between two treatments: T20) only skid road harvest (20 m distance between ca. 4 m wide roads), and T40) skid road harvest (40 m distance between ca. 4 m wide roads) combined with thinning between the roads. In T40, the goal was to harvest approximately the same standing volume as in T20. After harvest, two circular sample plots (radius 18 m, i.e. 1018 m2) were established at random locations within each treated area. All mechanical damage on the stem caused by harvest was measured and registered, including bark stripping larger than 15 cm2, stem broken or split, and tearing of branches causing damage on the stem. About 70–90 per cent of the damaged trees were smaller than 15 cm dbh. Very few trees larger than 25 cm dbh were damaged. In T20, more than 50 per cent of the damaged trees were located less than 5 m from the skid road, compared to less than 25 per cent for T40, in which more than 50 per cent of the damaged trees were located 5–10 m from the skid road. Creating only half the number of skid roads caused no more damage, and was probably more profitable because mean stem volume was about 1.5 times larger than in T20.
  • Modig, Statens fastighetsverk, Jokkmokk, Sweden ORCID ID:E-mail:
  • Magnusson, Skogsstyrelsen, Bräcke, Sweden ORCID ID:E-mail:
  • Valinger, Deparment of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail:
  • Cedergren, Mariehamn, Åland ORCID ID:E-mail:
  • Lundqvist, Deparment of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail: lars.lundqvist@slu.se (email)
article id 442, category Research note
Emil Modig, Bo Magnusson, Erik Valinger, Jonas Cedergren, Lars Lundqvist. (2012). Damage to residual stand caused by mechanized selection harvest in uneven-aged Picea abies dominated stands. Silva Fennica vol. 46 no. 2 article id 442. https://doi.org/10.14214/sf.442
Permanent field plots were established in two uneven-aged Norway spruce (Picea abies (L.) Karst) dominated stands in west-central Sweden. The objective was to quantify level and type of damage caused by harvesting and to quantify the difference between two treatments: T20) only skid road harvest (20 m distance between ca. 4 m wide roads), and T40) skid road harvest (40 m distance between ca. 4 m wide roads) combined with thinning between the roads. In T40, the goal was to harvest approximately the same standing volume as in T20. After harvest, two circular sample plots (radius 18 m, i.e. 1018 m2) were established at random locations within each treated area. All mechanical damage on the stem caused by harvest was measured and registered, including bark stripping larger than 15 cm2, stem broken or split, and tearing of branches causing damage on the stem. About 70–90 per cent of the damaged trees were smaller than 15 cm dbh. Very few trees larger than 25 cm dbh were damaged. In T20, more than 50 per cent of the damaged trees were located less than 5 m from the skid road, compared to less than 25 per cent for T40, in which more than 50 per cent of the damaged trees were located 5–10 m from the skid road. Creating only half the number of skid roads caused no more damage, and was probably more profitable because mean stem volume was about 1.5 times larger than in T20.
  • Modig, Statens fastighetsverk, Jokkmokk, Sweden ORCID ID:E-mail:
  • Magnusson, Skogsstyrelsen, Bräcke, Sweden ORCID ID:E-mail:
  • Valinger, Deparment of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail:
  • Cedergren, Mariehamn, Åland ORCID ID:E-mail:
  • Lundqvist, Deparment of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail: lars.lundqvist@slu.se (email)

Category: Discussion article

article id 573, category Discussion article
Matti Koivula, Jari Niemelä. (2002). Boreal carabid beetles (Coleoptera, Carabidae) in managed spruce forests – a summary of Finnish case studies. Silva Fennica vol. 36 no. 1 article id 573. https://doi.org/10.14214/sf.573
  • Koivula, Department of Ecology and Systematics, Division of Population Biology, P.O. Box 65, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail: matti.koivula@helsinki.fi (email)
  • Niemelä, Department of Ecology and Systematics, Division of Population Biology, P.O. Box 65, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:

Category: Article

article id 7182, category Article
Kauko Hahtola. (1967). Hankintahakkuut ja maatilakokonaisuus. Acta Forestalia Fennica vol. 84 no. 1 article id 7182. https://doi.org/10.14214/aff.7182
English title: Delivery cuts of timber in farm management.

The study links up with the general development of logging on private farm woodlots, practiced by the Work Efficiency Institute (Työtehoseura). It is based on the idea that the promotion of forest management on farms should be integrated with general agricultural development. The aim of the study was to find out the relation between delivery cuts and management of the farm as a whole, including economic and social environment. The first, methodological part develops a model representing farming, based on factor analysis. The second part tests the applicability of the factor analysis in the light of the empirical data, and studies the relation between delivery cuts and total farming and regional differences in farming.

Despite the descriptive nature of the factors obtained, the solution permitted a multi-dimensional examination. It seems that certain aspects typical to scattered settlement accentuate the importance of the forest for the farm. These include a high ratio of forest to arable land, barren soil and forest holdings that form unbroken tract of land. The importance of forestry is accentuated by the self-sufficiency of farms in labour and tractive power. On the other hand, there were lines of production and forms of livelihood and land utilization that compete with forestry, such as off-farm employment and alternative forms of land-use. One factor indicative for small importance of forestry for the farms was the small size in ratio to arable land. Often money for machinery has come from forest revenues.

The factor analysis indicate that a rational parcelling of forest holdings leads to better cutting methods. Also, cutting method improve and the proportion of renewal cuttings increase on moving from remote areas towards population centers. Productivity of delivery cuts is affected by the total employment of labour and tractive power on the farm. Abundance of labour and the use of farm’s own labour are probably detrimental to the productivity of delivery cuts. When the farms grow, the increase in the quantity felled and the rise in the degree of mechanization favour productivity.

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  • Hahtola, ORCID ID:E-mail:
article id 7474, category Article
Jouko Einola. (1957). Puutavaran hankinnan yhteiskustannukset. Acta Forestalia Fennica vol. 66 no. 4 article id 7474. https://doi.org/10.14214/aff.7474
English title: Joint costs of logging in Finland.

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

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  • Einola, ORCID ID:E-mail:
article id 7322, category Article
Ilmari Vuoristo. (1935). Työennätykset tukkien teossa ja ajossa Perä-Pohjolassa. Acta Forestalia Fennica vol. 42 no. 5 article id 7322. https://doi.org/10.14214/aff.7322
English title: Working efficiency in timber cutting and hauling in Northern Ostrobothnia.

The aim of the study was to determine how different factors in the stand influence working efficiency in felling. In the eight cutting areas in Northern Finland was harvested a total of 745,200 cubic feet of timber. The factors recorded from the cutting areas were the number of stems per hectare, volume of the stems, quality of the logs (proportion of decayed trees and knottiness of the trees), topography of the site and efficiency of the workers in a team.

The bigger the stems were, the better the result of the workers was. When the size of the stem increased by one cubic ft., the efficiency of the work increased by 2 cubic ft. When knottiness and defects in the stem changed the class describing the quality of a tree by one class, the efficiency decreased by 4.5 cubic ft. The density of the forest affected the time used for loading the timber for hauling. The hauling distance affected the efficiency of the team, which was usually either 2 men and one horse, or 3 men and one horse. If the hauling distance was long, hauling impaired the efficiency. If the distance was short, logging impaired the efficiency of the work. The result show that efficiency of forest work is greatly influenced by the quality of the forest, the trees and the workers.

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  • Vuoristo, ORCID ID:E-mail:
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

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, ORCID ID:E-mail:
article id 5564, category Article
Jerry Johansson. (1995). Backhoe loaders as base machines in logging operations. Silva Fennica vol. 29 no. 4 article id 5564. https://doi.org/10.14214/sf.a9215

Time studies and an ergonomic assessment were carried out in logging operations for three logging machines based on backhoe loader chassis. The time studies were completed with a follow-up study of one backhoe loader-based single-grip harvester. The studies indicated a productivity at the same level as that of specialized Nordic logging machines. Ergonomics also proved to be good. Mean ground pressure exerted by the backhoe loader-based logging machines was little higher than for some of the conventional Nordic single-grip harvesters to which it was compared. The ability of the machines to operate in the terrain was also good, even in rough terrain.

These machines can also be used for other jobs, such as ditch digging, road building and road maintenance. The machines then function more as carriers for attachments rather than custom-built backhoe loaders. By more careful planning of operations, the machines can be used to a higher degree and more effectively. The relatively low investment cost compared to many custom-built Nordic logging machines also contributes to a reduction of operating costs.

  • Johansson, ORCID ID:E-mail:
article id 7089, category Article
A. Benj. Helander. (1923). Metsätalouden tarjoamasta ansiotyöstä. Acta Forestalia Fennica vol. 26 no. 1 article id 7089. https://doi.org/10.14214/aff.7089
English title: Employment in the forestry in Finland.

Work in the forestry, for instance, in logging operation during winter, has been important source of employment for the rural population in Finland. The study is based on statistics of forest work, felling, felled timber, workforce and horses used in the forest work in the state forests, published in the annual reports of Metsähallitus (Forest Service) in 1911-1913. The administrative and silvicultural work, for instance, sowing and planting, clearing of the felling area, building forest roads or work in the nurseries, range from 20% to 22% of all work done in the forestry. Major part of the work time is used in felling. To harvest one cubic meter of timber requires 0.3 man-days and 0.2 horse-days. The work is seasonal; felling work is available for about 90-100 days a year. Forest haulage is possible only in the winter, and for instance sowing and planting in the summer. The employees have secondary jobs in agriculture and in other sectors.

The PDF includes a summary in German.

  • Helander, ORCID ID:E-mail:
article id 5314, category Article
M. Saarilahti, E. Bakena, G. Mboya, T. Minja, T. Ngerageze, J. Ntahompagaze. (1987). Studies on Tanzanian forest work. Silva Fennica vol. 21 no. 2 article id 5314. https://doi.org/10.14214/sf.a15471

Four teams of two workers were time-studied in clearcutting of a cypress plantation and three teams in sulky skidding. The heart rate was recorded every 30 s. The average heartrate in timber cutting was 117.5 ± 13.4 P/min, and it was mainly dependent on worker’s working capacity. Average work load index was 41 ± 3% when working at 97% performance. The production rate was then 2.5 m3/h (crew). In sulky skidding the heart rate was lower, 106 ± 1.1 P/min, as well as the work load (WLI 30 ± 1%) and performance rating (87%). The low production rate (1.1 m3/h) (crew)) over 45 m distance is mainly due to under-dimensioned load size. The energy expenditure in timber cutting was 21.4 kJ/min and in sulky skidding 16.3 kJ/min. Daily energy expenditure was 15.0 MJ/d, and most of the timber cutters belonged to the class ”exceptionally active”.

The PDF includes an abstract in Finnish.

  • Saarilahti, ORCID ID:E-mail:
  • Bakena, ORCID ID:E-mail:
  • Mboya, ORCID ID:E-mail:
  • Minja, ORCID ID:E-mail:
  • Ngerageze, ORCID ID:E-mail:
  • Ntahompagaze, ORCID ID:E-mail:
article id 5308, category Article
Martti Saarilahti, R. E. L. Ole-Meiludie. (1987). Production rate and work strain on workers in cutting of pines in Tanzania. Silva Fennica vol. 21 no. 1 article id 5308. https://doi.org/10.14214/sf.a15465

A team of 2 experienced workers was time-studied and their heart rate recorded under 4 days in clearcutting of a highly self-pruned Pinus patula Schltdl. & Cham. plantation. Task work and bonus payment systems were compared, but there was no difference in production rate, only the workplace time was extended from 2.3 h/d in task work to 3.9 h/d in bonus payment. The heart rate was 115–116 P/min in felling, 105–109 P/min in debranching and 109–114 P/min in bucking. The average heart rate in timber cutting was 108–109 P/min. Work load index was 34–37%, and the workers did not show any symptoms of accumulated stress. The production rate was 3.2 m3/h, (WPT, crew), which corresponds average piecework rate, the comparable walking speed being about 6.0 km/h. There are possibilities to increase the daily task by ergonomic grounds.

The PDF includes an abstract in Finnish.

  • Saarilahti, ORCID ID:E-mail:
  • Ole-Meiludie, ORCID ID:E-mail:
article id 5304, category Article
Jimin Tan. (1987). A method to evaluate productivity of logging machines. Silva Fennica vol. 21 no. 1 article id 5304. https://doi.org/10.14214/sf.a15461

This study deals with the evaluation of logging machines. The analyses were based on the results of a productivity study with special reference to a PIKA 35 processor, a delimber-bucker, working in Kyröskoski forest area in Finland. Factors affecting the productivity of the machine were surveyed. Mathematical models for determining the productivity were developed and their practical applications to the particular problem under study was demonstrated.

The PDF includes an abstract in Finnish.

  • Tan, ORCID ID:E-mail:
article id 5227, category Article
Harri Vasander, Tapio Lindholm. (1985). Tulen voimakkuus ja maanpinnan lämpötila kulotuksen aikana. Silva Fennica vol. 19 no. 1 article id 5227. https://doi.org/10.14214/sf.a15406
English title: Fire intensities and surface temperatures during prescribed burning.

Surface temperature during two prescribed burnings were measured in 1983 in Evo, Southern Finland. Surface temperatures in relation to the amount of slash burned, energy released during the fires, and the fire intensities were studied. The fire intensity was also measured during a third burn. The Lake Nimetön site was burned int the end of May. Due to the uneven distribution of slash, colonization by Calamagrostis arundinacea and the spring moisture, the burning was very uneven. Surface temperatures varied between 410–809°C and the intensity of fire was low (range 0–900 kW/m).

The fire intensity on the other sites burned in May was also low (880 kW/m). During the burn in August the surface temperatures varied between 701–869°C and the intensity of fire was moderate (1,170 kW/m). Slash was burned more evenly and more thoroughly due to the dryness of the site and slash and the fact that grasses and other herbs were not abundant.

The PDF includes a summary in Finnish.

  • Vasander, ORCID ID:E-mail:
  • Lindholm, ORCID ID:E-mail:
article id 5179, category Article
Pertti Harstela, Antti Maukkonen. (1983). Tavanomainen ja kuormainprosessori varttuneissa harvennusmetsiköissä. Silva Fennica vol. 17 no. 2 article id 5179. https://doi.org/10.14214/sf.a15095
English title: A conventional and grapple loader processor in second and third thinnings. A simulator experiment.

Using literature and a simulator experiment, an ordinary processor and a grapple loader processor were compared in conditions corresponding to thinning later than the first commercial thinning. Visual bucking only was employed in the simulator experiment. The strip road spacing was 30 m and there was no preliminary skidding of the trees. The simulator experiment confirmed the view reached in the literature that work productivity of the grappler loader processor is 20–40 % greater than that of an ordinary processor provided that the stem size is under 0.2–0.4 m3.

The PDF includes a summary in English.

  • Harstela, ORCID ID:E-mail:
  • Maukkonen, ORCID ID:E-mail:
article id 5126, category Article
Martti Saarilahti. (1981). Koneiden uppoaminen suometsien puunkorjuussa. Silva Fennica vol. 15 no. 3 article id 5126. https://doi.org/10.14214/sf.a15067
English title: Sinkage of forest machines during harvesting operations on peatlands.

Questionnaires were sent out to determine the volume of wood harvested from peatlands during 1978 and the harvesting problems encountered. In total there were 110 responses which accounted for 8 million m3 of wood harvested, of which 1.0 million m3 (14%) was harvested from peatlands. The largest proportion of wood harvested from peatlands was during the winter. Most of the respondents reportet that they wait for the soil frost to set before harvesting is started on peatlands. Respondents indicated a total of 263 machines bogging down in to the soil or, for 1978, a total for Finland of 750 to 1,000 machines.
The PDF includes a summary in English.

The PDF includes a summary in English.

  • Saarilahti, ORCID ID:E-mail:
article id 5119, category Article
Kari Puukko. (1981). Okakaarnakuoriaisen, Ips acuminatus Gyll. (Coleoptera, Scolytidae) levinneisyyden nykyinen eteläraja Suomessa. Silva Fennica vol. 15 no. 2 article id 5119. https://doi.org/10.14214/sf.a15060
English title: The southern border of the present distribution of Ips acuminatus Gyll. In Finland.

Ips acuminatus Gyll. (Coleoptera, Scolytidae) is a bark beetle that causes deep bluing in thin-barked Scots pine (Pinus sylvestris L.) pulpwood. It has been shown that this decreases pulp yield. The purpose of this study was to map the southern border of the distribution of Ips acuminatus in Finland. It was found that there have been changes in the distribution of this species during the last three decades. Ips acuminatus has now disappeared from southern Finland. On the basis of the sample plots (134 cutting areas) the southern border of this pest lies on the line running through the towns Vaasa–Seinäjoki–Äänekoski–Jyväskylä–Pieksämäki–Savonlinna–Punkaharju. A certain degree of localisation was observed in the occurrence of I. acuminatus in its distribution area, for instance, differences in its occurrence frequency in cutting areas and even in log and cutting residue piles in the sample cutting area.

It is considered that the most important reasons for these changes in distribution are the increase in logging and changes in the location of cutting sites, and resulting competition for breeding material for the increased population of bark beetles. Furthermore, the long-distance transport of unpeeled logs from the north across the present southern borders may, in the future, contribute to local changes in the southern distribution of Ips acuminatus.

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  • Puukko, ORCID ID:E-mail:
article id 5107, category Article
Lars Lönnstedt. (1981). The influence of Swedish forestry policy on the annual cuts of private woodlot owners. Silva Fennica vol. 15 no. 1 article id 5107. https://doi.org/10.14214/sf.a15048

The purpose of this paper is to discuss the effect that the various measures by society have on bringing the level of the annual cut by private woodlot owners in line with the forestry policy goal of a long-term sustained yield of wood. The objectives and measures of forest policy in Sweden are described, as well as the central relations which explain the development in the logging policies of the private woodlot owners.

The goal of Swedish forestry policy has long been to safeguard a sustained yield of wood. This demand has successively been tightened, defined and detailed. The principle measure employed by the authorities to obtain the goal has been silvicultural legislation.

The author summarises that of all the means available of influencing the logging policy of private woodlot owners the most effective is silvicultural legislation. However, when viewed in an historical perspective, the legislation has not been able to significantly regulate the level of the annual cut. Nevertheless, at a time when there is a shortage of wood materials the legislation will undoubtedly exert a greater influence. Changes in forest taxation could prove to be an effective means in future of, for example, achieving an increase in the annual cut of private woodlot owners.

  • Lönnstedt, ORCID ID:E-mail:
article id 4999, category Article
Tapio Klen, Veikko Louhevaara. (1978). Metsurin suojavarusteiden aiheuttama lisäkuormitus. Silva Fennica vol. 12 no. 3 article id 4999. https://doi.org/10.14214/sf.a14853
English title: The additional physical strain caused by safety equipment in logging work.

The safety clothing, rubber safety boots, belt with lifting hooks and personal protectors can weight about 3 kg more than the normal work clothing including rubber boots. In order to evaluate the increase off the physical strain in logging work due to them, laboratory tests performed on tread mill were made. The physical strain increased 3–11% as estimated from heart rate and 4–8% as estimated from oxygen consumption measurements.

The PDF includes a summary in English.

  • Klen, ORCID ID:E-mail:
  • Louhevaara, ORCID ID:E-mail:
article id 4974, category Article
Markku Mäkelä. (1977). Teknisesti korjattavissa oleva hakkuutähde sekä kanto- ja juuripuu Kaakkois-Suomessa. Silva Fennica vol. 11 no. 3 article id 4974. https://doi.org/10.14214/sf.a14825
English title: The amounts of logging residues and stump and root wood technically harvestable in southeast Finland.

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

The PDF includes a summary in Finnish.

  • Mäkelä, ORCID ID:E-mail:
article id 4970, category Article
Markku Mäkelä. (1977). Metsähakkeen tiheyden laskeminen. Silva Fennica vol. 11 no. 2 article id 4970. https://doi.org/10.14214/sf.a14821
English title: Calculating the basic density of whole tree- and logging residue chips.

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

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  • Mäkelä, ORCID ID:E-mail:
article id 4955, category Article
Suomen Metsäteollisuuden Keskusliitto. (1976). Puutavaraselvitys 1976. Silva Fennica vol. 10 no. 4 article id 4955. https://doi.org/10.14214/sf.a14801
English title: Timber report 1976. – Finland’s roundwood, industrial residue and forest residue balances by 1980 as well as the wood raw material situation of Finnish forest industries by the year 2000.

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

The PDF includes a summary in English.

  • Suomen Metsäteollisuuden Keskusliitto, ORCID ID:E-mail:
article id 4944, category Article
Eino Mälkönen. (1976). Effect of whole-tree harvesting on soil fertility. Silva Fennica vol. 10 no. 3 article id 4944. https://doi.org/10.14214/sf.a14790

This paper analyses the nutrient loses caused by whole-tree harvesting on the basis of the literature data. It has been considered that traditional stemwood harvesting does not lead to impoverishment of the soil because the nutrient content of the wood is quite low. The nutrient loss occurring in connection with heavy thinnings and whole-tree harvesting has been considered so great that it has to be compensated by fertilizer application. In comparison with harvesting unbarked stem timber, whole-tree harvesting has been found to increase the nutrient loss at the stage of final cutting as follows: N2 to 4 times, P 2 to 5 times, K 1.5 to 3.5 times and Ca 1.5 to 2.5 times. Depending on the conditions prevailing on the site, any one of these nutrients may be the limiting factor for tree growth during the next tree generation

The PDF includes a summary in Finnish.

  • Mälkönen, ORCID ID:E-mail:
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.

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, ORCID ID:E-mail:
article id 4874, category Article
Matti Kärkkäinen. (1973). Runkojen järeys puunkorjuun monitoimikoneiden ajanmenekin ennustamisessa. Silva Fennica vol. 7 no. 1 article id 4874. https://doi.org/10.14214/sf.a14704
English title: The size of stems in estimating the time consumption of processors.

The problem considered in this paper is how to analyse the usefulness of some average volume values of stems in predicting the average time consumption of some processors. In this connection, the usual arithmetic mean, the arithmetic mean weighted with volume and the geometric mean were used. The functions describing the dependence of time consumption per tree on the volume of the tree were obtained from previous studies, as were the stand properties.

The results were obtained with the aid of computer simulation techniques and the deterministic model described above. According to the results, the usual arithmetic mean is very applicable for predicting the time consumption. The geometric mean is nearly as good, or in some cases even better. However, as a rule its computation is much more tedious than that of the arithmetic average volume for the purpose.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
article id 4848, category Article
Matti Kärkkäinen. (1971). Lahon leviäminen puunkorjuun aiheuttamista kuusen runko- ja juurivaurioista. Silva Fennica vol. 5 no. 3 article id 4848. https://doi.org/10.14214/sf.a14650
English title: Decay following logging injury in stems and roots of Norway spruce.

The material of 78 damaged Norway spruce (Picea abies (L.) H. Karst.) trees was gathered in Southern Finland in order to clarify the advance of decay. The harvesting which had caused the scars had been carried out 12 years earlier and at the moment of the investigation the growing stand was 110 years old. It was noticed that the variables used could explain only a few per cent of the variation of the advance of decay. It was concluded that the only important thing in practice is whether the injuries are in roots or in stems.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
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.

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, ORCID ID:E-mail:
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.

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, ORCID ID:E-mail:
article id 4736, category Article
Matti Nuorteva. (1967). Hakkuutähteissä elävien hyönteisten käyttömahdollisuuksista hakkuun ajankohdan määrittämisessä. Silva Fennica vol. 1 no. 1 article id 4736. https://doi.org/10.14214/sf.a14446
English title: Potential in using determination of insect species breeding in the logging residue to estimate the time of the logging.

Degree of decomposition of logging residue, and decay in stumps have been used in forest inventories to estimate the time of the felling. In this paper, a method was developed to use insects breeding in the logging residue to determine how long ago the felling took place. The method is based on the arrival and rate of development of the different species of bark beetles that breed in the logging residue.

The most suitable insect species to be used in the purpose of timing the age of logging residue were defined, and their occurrence in different tree species and fellings performed at different times of the year were described. The species can be easily identified by gallery systems characteristic to the species.

It is concluded that the method does not suit for broadleaved species, because there is no common insects suitable for this purpose. Also, the time of swarming of the insects depends on the weather conditions in the spring, which makes it difficult to give definite dateshe progress of the spring has to be taken into account when the occurrence of the insects is used in the determination of the time of the felling. In addition, local conditions, such as shading, affect drying of the branches, and can influence the occurrence of the insects. For Scots pine and Norway spruce the age of the logging residue can be determined precisely only at most two years back.

  • Nuorteva, ORCID ID:E-mail:
article id 4736, category Article
Matti Nuorteva. (1967). Hakkuutähteissä elävien hyönteisten käyttömahdollisuuksista hakkuun ajankohdan määrittämisessä. Silva Fennica vol. 1 no. 1 article id 4736. https://doi.org/10.14214/sf.a14446
English title: Potential in using determination of insect species breeding in the logging residue to estimate the time of the logging.

Degree of decomposition of logging residue, and decay in stumps have been used in forest inventories to estimate the time of the felling. In this paper, a method was developed to use insects breeding in the logging residue to determine how long ago the felling took place. The method is based on the arrival and rate of development of the different species of bark beetles that breed in the logging residue.

The most suitable insect species to be used in the purpose of timing the age of logging residue were defined, and their occurrence in different tree species and fellings performed at different times of the year were described. The species can be easily identified by gallery systems characteristic to the species.

It is concluded that the method does not suit for broadleaved species, because there is no common insects suitable for this purpose. Also, the time of swarming of the insects depends on the weather conditions in the spring, which makes it difficult to give definite dateshe progress of the spring has to be taken into account when the occurrence of the insects is used in the determination of the time of the felling. In addition, local conditions, such as shading, affect drying of the branches, and can influence the occurrence of the insects. For Scots pine and Norway spruce the age of the logging residue can be determined precisely only at most two years back.

  • Nuorteva, ORCID ID:E-mail:
article id 7517, category Article
Juha Nurmi. (1997). Heating values of mature trees. Acta Forestalia Fennica no. 256 article id 7517. https://doi.org/10.14214/aff.7517

The effective heating values of the above and below ground biomass components of mature Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), downy birch (Betula pubescens Ehrh), silver birch (B. pendula Roth), grey alder (Alnus incana (L.) Moench), black alder (A. glutinosa (L.) Gaertn.) and aspen (Populus tremula L.) were studied. Each sample tree was divided into wood, bark and foliage components. Bomb calorimetry was used to determine the calorimetric heating values.

The species is a significant factor in the heating value of individual tree components. The heating value of the wood proper is highest in conifers. Broadleaved species have a higher heating value of bark than conifers. The species factor diminishes when the weighted heating value of crown, whole stems or stump-root-system are considered. The crown material has a higher heating value per unit weight in comparison with fuelwood from small-sized stems or whole trees. The additional advantages of coniferous crown material are that it is non-industrial biomass resource and is readily available. The variability of both the chemical composition and the heating value is small in any given tree component of any species. However, lignin, carbohydrate and extractive content were found to vary from one part of the tree to another and to correlate with the heating value

  • Nurmi, ORCID ID:E-mail:
article id 7654, category Article
Pentti Hakkila. (1989). Logging in Finland. Acta Forestalia Fennica no. 207 article id 7654. https://doi.org/10.14214/aff.7654

Due to the high level of salaries and cost of social security, strict ergonomic standards, specific logging conditions, predominance of private ownership, and strong influence of environmental and conservation aspects, the Nordic countries have been forced to develop completely new logging technology to meet their own specific requirements. Demanding domestic markets have created a strong base for the production and export of forest machines. In the 1980’s Finland has become the leading manufacturer of logging machinery in Europe.

The Finnish logging technology rests typically on the log-length method and the use of load-carrying forwarders. This constrains the export of logging machinery in many countries, but as increasing emphasis is placed on thinnings, improved timber recovery, productivity, ergonomics, and protection of environment, increasing interest is shown in this technology.

The paper presents a synthesis of logging in Finland. The technical logging conditions, development of mechanization, present technology, productivity of work, and forest machine industry are explained and reviewed from the view point of a foreign reader.

The PDF includes a summary in Finnish.

  • Hakkila, ORCID ID:E-mail:
article id 7589, category Article
Eero Kubin. (1977).  . Acta Forestalia Fennica no. 155 article id 7589. https://doi.org/10.14214/aff.7589
English title: The effect of clear cutting upon the nutrient status of a spruce forest in Northern Finland (64 28'N).

The purpose of this paper was to determine the proportions of nutrients remaining in the forest and removed from the forest as a result of cutting. The Norway spruce (Picea abies (L.) H. Karst.) phytomass remaining after clear cutting was studied in the categories of tree-top waste, branches, twigs, needles and cones. The bole wood, measured in solid cubic metres, was converted to kilogrammes on the basis of relative density determinations, and the amount of stump and root material estimated from the known amount of bole wood and comparable data presented in the literature. The nutrients studied were N (Kjeldahl), P (colour reaction), K, Ca, Mg, Fe and Mn (atomic absorption spectrophotometer). The wood and bark were studied separately. Details of the mineral composition of the bedrock are also presented.  

The harvested timber was found to account for 46 % of the total phytomass, or 58 % of the aerial phytomass, while the stump and root material represented one fifth of the total phytomass. The needles and bark contained the highest proportions of nutrients, especially in the case of nitrogen and phosphorus, the needles containing 32 % of total nitrogen and 26 % of total phosphorus. The surface waste wood contained on average more than double the amount of nutrients compared with the harvested bole wood, including more than six times the amount of phosphorus. Approximately one fifth of the nutrient contained in the total phytomass was removed on cutting. The high proportion of basic rocks in the area is suggested as an explanation of the nutrient status at the site, which is in many ways better than that described in the results of other investigations.  

The PDF includes a summary in Finnish. 

  • Kubin, ORCID ID:E-mail:
article id 7570, category Article
Antti Isomäki, Tauno Kallio. (1974). Consequences of injury caused by timber harvesting machines on the growth and decay of spruce (Picea abies (L.) Karst.). Acta Forestalia Fennica no. 136 article id 7570. https://doi.org/10.14214/aff.7570

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

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

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

The PDF includes a summary in Finnish.

  • Isomäki, ORCID ID:E-mail:
  • Kallio, ORCID ID:E-mail:
article id 7609, category Article
Matti Kärkkäinen. (1969). Metsän vaurioituminen kesäaikaisessa puunkorjuussa. Acta Forestalia Fennica no. 100 article id 7609. https://doi.org/10.14214/aff.7609
English title: The amount of injuries caused by timber transportation in the summer.

The purpose of this study was to build a mathematic predictive model for the formation of injuries and to try its usability in predicting. The empirical data consisted of 24 thinning sites, which were situated mainly in forests owned by forestry companies. The timber was made by strip roads. The terrain transportation of timber was carried out by forwarders or by agricultural tractor-trailer combinations.

The model has been compiled by multiple regression analysis. The predictive model has been interpreted so that the formation of injuries is, for one part, dependent of the number of trees exposed to damages, and, on the other hand, on the factors influencing the probability of injuries, the possibility for this existing. The number of trees exposed to injuries is dependent on the density of strip roads and on the amount of standing timber left after logging. The probability of injuries is influenced by the quality of the standing timber, the type of soil and the intensity of the timber harvesting process.

The predictive model has been interpreted in similar way as the number of injured trees. The possibility of formation of injuries is mainly affected by the length of strip roads and the amount of the standing timber. The probability of injuries is influenced, for the part of the number of root injuries by the strength of the soil type, and probably also by transportation equipment. For the amount of stem injuries no valid predictive equation was found in this study.

  • Kärkkäinen, ORCID ID:E-mail:
article id 7609, category Article
Matti Kärkkäinen. (1969). Metsän vaurioituminen kesäaikaisessa puunkorjuussa. Acta Forestalia Fennica no. 100 article id 7609. https://doi.org/10.14214/aff.7609
English title: The amount of injuries caused by timber transportation in the summer.

The purpose of this study was to build a mathematic predictive model for the formation of injuries and to try its usability in predicting. The empirical data consisted of 24 thinning sites, which were situated mainly in forests owned by forestry companies. The timber was made by strip roads. The terrain transportation of timber was carried out by forwarders or by agricultural tractor-trailer combinations.

The model has been compiled by multiple regression analysis. The predictive model has been interpreted so that the formation of injuries is, for one part, dependent of the number of trees exposed to damages, and, on the other hand, on the factors influencing the probability of injuries, the possibility for this existing. The number of trees exposed to injuries is dependent on the density of strip roads and on the amount of standing timber left after logging. The probability of injuries is influenced by the quality of the standing timber, the type of soil and the intensity of the timber harvesting process.

The predictive model has been interpreted in similar way as the number of injured trees. The possibility of formation of injuries is mainly affected by the length of strip roads and the amount of the standing timber. The probability of injuries is influenced, for the part of the number of root injuries by the strength of the soil type, and probably also by transportation equipment. For the amount of stem injuries no valid predictive equation was found in this study.

  • Kärkkäinen, ORCID ID:E-mail:
article id 7603, category Article
Olli Makkonen. (1969). Ancient forestry : A historical study. Part II, The procurement and trade of forest products. Acta Forestalia Fennica no. 95 article id 7603. https://doi.org/10.14214/aff.7603

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

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

  • Makkonen, ORCID ID:E-mail:
article id 7189, category Article
Pentti Alho. (1968). Pohjois-Pohjanmaan metsien käytön kehitys ja sen vaikutus metsien tilaan. Acta Forestalia Fennica no. 89 article id 7189. https://doi.org/10.14214/aff.7189
English title: Utilization of forests in north Ostrobothnia and its effect on their condition.

The purpose of the present investigation was to study the extent of human interference with the forests of different epochs in the district of north Ostrobothnia in Northern Finland, and its effect on the condition of the forests.

The study revealed that the quantities of wood removed were not most detrimental to the condition of the forest; the regionally irregular loggings and the logging methods employed were the most harmful. The old forms of wood utilization, tar industry, shipbuilding, sawmill industry and timber exports, were characterized by timber selection. Public opinion considered it the only recognized cutting method long after the conditions had changed and silvicultural methods should have been used.

The spread and abandonment of selection cuttings are illustrated in the results of first National Forest Surveys in Finland. According to the first survey (1921–1924), nearly half of the loggings in the province of Oulu were based on selection, which spoiled and devastated 41% of the forests. In the 1930s one-fifth of the North Ostrobothnian forests were weakened by selection cuttings, in 1960s the figure was 6%. The article also summarises the extent of tar and pitch production, sawmill industry, shipbuilding and household wood consumption of wood in the area.

The PDF includes a summary in English

  • Alho, ORCID ID:E-mail:
article id 7185, category Article
Jouko Mäkelä. (1968). Puunkorjuun tuottavuuteen vaikuttavat tekijät maatilametsätaloudessa. Acta Forestalia Fennica no. 85 article id 7185. https://doi.org/10.14214/aff.7185
English title: Factors affecting logging productivity in farm forestry.

This is a fourth paper in a series of studies concerning logging in farm forests. The objective was to construct a model representing the productivity per farm of logging for delivery cuts. The first objective was to find out how the productivity of logging should be measured. In the study, combined labour and capital are regarded as the input.

Second object was to consider what variables to use in theory to determine the productivity of logging for delivery cuts. The factors affecting productivity depend on the concept of productivity employed. The productivity per farm of logging in delivery cuts can be determined both by regional and by farm variables. Still considering solely the effect of the quality of labour and capital input, the variables representing the person in charge of the delivery cuts are important explanatory farm variables. Others represent the farm totality (size, lines of production etc.).

Third aim was to develop a statistical-mathematical method suitable for constructing the model. Possible methods include regression analysis, which is, however, not the best method when there is large number of different levels to explain, or factor analysis. The suitable method to use in constructing a model depicting the productivity of a farm, was considered to be to condense the explanatory variables into rotated orthogonal factors. After preliminary correlation analysis, estimates of the factors interpreted as rational were employed as the explanatory variables for selective regression analysis.

Last, the model was tried out against actual material collected per farm, and the hypotheses were tested.

The PDF includes a summary in English.

  • Mäkelä, ORCID ID:E-mail:
article id 4734, category Article
Yrjö Kangas. (1966). Valtion metsien hakkuupoistuma ja sen rakenne : Vuosiin 1954-1958 kohdistuva selvittely. Silva Fennica no. 120 article id 4734. https://doi.org/10.14214/sf.a14292
English title: Felling volume and its structure in the Finnish State Forests in 1954-1958 .

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

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

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

The PDF includes a summary in German.

  • Kangas, ORCID ID:E-mail:
article id 4590, category Article
E. A. Sopanen. (1948). Hankintatöiden paikallinen organisointi. Silva Fennica no. 64 article id 4590. https://doi.org/10.14214/sf.a13992
English title: Organizing delivery loggings locally.

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

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

  • Sopanen, ORCID ID:E-mail:

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