Current issue: 53(1)

Under compilation: 53(2)

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Silva Fennica 1926-1997
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Acta Forestalia Fennica
1953-1968
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Articles containing the keyword 'silviculture'.

Category: Research article

article id 1665, category Research article
Lauri Haataja, Ville Kankaanhuhta, Timo Saksa. (2018). Reliability of self-control method in the management of non-industrial private forests. Silva Fennica vol. 52 no. 1 article id 1665. https://doi.org/10.14214/sf.1665
Highlights: Self-control method was found reliable at the main stages of the forest regeneration process; Only slight overestimation was found in self-control results of soil preparation and planting and small underestimation in self-control of young stand management; Diverse utilizing of self-control data is possible in support of service providers operations.
This study seeks to determine the extent to which self-control data can be relied upon in the management of private forests. Self-control (SC) requires the forest workers to evaluate their own work quality to ensure the clients’ needs are met in terms of soil preparation, planting and young stand management. Self-control data were compared to an independent evaluation of the same worksites. Each dataset had a hierarchical structure (e.g., sample plot, regeneration area and contractor), and key quality indicators (i.e., number of prepared mounds, planted seedlings or crop trees) were measured for each plot.  Self-control and independent-assessments (IA) were analyzed by fitting a multi-level multivariate model containing explanatory variables. No significant differences were observed in terms of soil preparation (number of mounds) or young stand management (number of crop trees) between self-control and independent-assessments. However, the self-control planting data included a slight but significant overestimation of the number of planted seedlings. Discrepancies are discussed in terms of sampling error and other explanatory factors. According to overall results, self-control methods are reliable at every stage of the forest regeneration process. As such, the diverse utilizing of self-control data is possible in support of service providers operations.
  • Haataja, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: lauritapiohaataja@gmail.com (email)
  • Kankaanhuhta, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: ville.kankaanhuhta@luke.fi
  • Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: timo.saksa@luke.fi
article id 1514, category Research article
Heidi Hallongren, Ville Kankaanhuhta, Mikael Kukkonen. (2016). Cleaning Scots pine seedling stands with mechanical uprooters – a work quality comparison of two related devices. Silva Fennica vol. 50 no. 3 article id 1514. https://doi.org/10.14214/sf.1514
Highlights: The productivity of the narrower modified device was significantly better than the wider original device; Work quality did not differ significantly between devices when stand characteristics, regeneration success and pre-existing damage were taken into account; Results indicate that mechanical uprooting devices may be further developed to a cost-effective alternative to motor-manual techniques for the early cleaning of direct seeded commercial Scots pine stands.

Commercial forests require early cleaning to ensure the unhindered and uniform growth of crop trees. In order to be cost effective, non-crop vegetation should be uprooted to prevent their recovery. Performing this work manually is a labour-intensive task but it can be done mechanically. We evaluated the efficiency of two uprooting devices in direct seeded Scots pine (Pinus sylvestris L.) stands ca. 1 m tall. Productivity and quality of the uprooting work was investigated across eight stands and ca. 160 sample plots in northern Karelia, eastern Finland. Time consumption of the uprooters was analyzed through a linear regression model and the work quality through a multilevel multivariate model in terms of the number of individual Scots pine seedlings, processing units (i.e., a bunch of seedlings to be harvested in the future) and broadleaves. The productivity of the narrower modified device was significantly better in terms of time consumption than the wider original device. Work quality did not differ significantly between devices when stand characteristics, regeneration success and pre-existing damage were taken into account. Results indicate that mechanical uprooting devices may be further developed to a cost-effective alternative to motor-manual techniques for the early cleaning of direct seeded commercial Scots pine stands.

  • Hallongren, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: heidi.hallongren@luke.fi (email)
  • Kankaanhuhta, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: ville.kankaanhuhta@luke.fi
  • Kukkonen, University of Eastern Finland, School of Forest Sciences. P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: mikaelkukkonen@hotmail.com
article id 1386, category Research article
Håkan Lideskog, Magnus Karlberg. (2016). Simulated continuous mounding improvements through ideal machine vision and control. Silva Fennica vol. 50 no. 2 article id 1386. https://doi.org/10.14214/sf.1386
Highlights: Different strategies for how to utilise machine vision to streamline the mounding head movements were developed and evaluated; The theoretical minimum rate of encountered obstacles while utilising machine vision in continuous mounding is presented, provided that an optimal continuous mounding has been performed; The needed minimum resolution of a machine vision system at work on a clearcut area was found.

To promote the growth and survival of regenerated forests, site preparation prior to tree planting on clearcuts is necessary. This is often performed with scarifiers, either through trenching or mounding. Mounding is generally considered better in a plant survival perspective but is inefficient on obstacle-rich clearcuts. By utilising machine vision through e.g. remote sensing methods, new strategies can enable efficient mound positioning. In this paper, three realistic strategies utilizing ideal clearcut object identification through machine vision have been developed that can be used for more efficient mounding. The results show that mounding efficiency can be significantly improved with a new mound positioning strategy that employs ideal object identification, especially on obstacle-rich clearcuts.

 

 

  • Lideskog, Luleå University of Technology, Department of Engineering Sciences and Mathematics, Division of Product and Production Development, SE-971 87 Luleå, Sweden ORCID ID:E-mail: hakan.lideskog@ltu.se (email)
  • Karlberg, Luleå University of Technology, Department of Engineering Sciences and Mathematics, Division of Product and Production Development, SE-971 87 Luleå, Sweden ORCID ID:E-mail: magnus.karlberg@ltu.se
article id 1323, category Research article
Tiina Laine, Kalle Kärhä, Antti Hynönen. (2016). A survey of the Finnish mechanized tree-planting industry in 2013 and its success factors. Silva Fennica vol. 50 no. 2 article id 1323. https://doi.org/10.14214/sf.1323
Highlights: In 2013, 31 planting machines were operated by 22 businesses and planted 4.7 million seedlings on 2663 hectares in Finland; Critical success factors included expertise of planting machine operators, high quality planting, adequate amount of work, stoniness, and removal of slash; Growth of the industry will depend on improved cost-efficiency, appropriate worksites, marketing, development of planting machines.

The aim of the study was to update the information pertaining to mechanized tree-planting activity in Finland in 2013 and its success factors. All businesses providing a mechanized tree-planting service were interviewed and asked to describe their equipment and activities, identify critical success factors (CSFs), and suggest areas for improvement. In 2013, 31 planting machines (18 Bracke P11.a, 11 M-Planter and 2 Risutec) operated by 22 businesses planted approximately 4.7 million seedlings on 2663 hectares. CSFs included expertise of planting machine operators, high quality planting, adequate amount of work, stoniness, and removal of slash. Based on the survey, some recommendations for improving mechanized planting work can be made. Firstly, improving the cost-efficiency of mechanized planting is necessary to enhance businesses’ profitability. Secondly, worksite selection is crucial as stoniness, stumps and slash debris diminish productivity. Lastly, the popularity of mechanized planting in the future will benefit from more marketing. Many businesses were unwilling to increase the area of service, invest in new equipment, or increase the volume of planting work but they believed that mechanized planting will become more popular in the near future.

  • Laine, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: tiina.laine@luke.fi (email)
  • Kärhä, Stora Enso Wood Supply Finland, P.O. Box 309, FI-00101 Helsinki, Finland ORCID ID:E-mail: kalle.karha@storaenso.com
  • Hynönen, University of Eastern Finland, Faculty of Science and Forestry, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: hynonena@gmail.com
article id 1141, category Research article
Isabel Miranda, Jorge Gominho, Helena Pereira. (2015). Heartwood, sapwood and bark variation in coppiced Eucalyptus globulus trees in 2nd rotation and comparison with the single-stem 1st rotation. Silva Fennica vol. 49 no. 1 article id 1141. https://doi.org/10.14214/sf.1141
Highlights: Coppiced E. globulus trees in the 2nd rotation have similar heartwood and sapwood development as single-stem trees in the 1st rotation; The initial tree planting density did not influence heartwood development of coppiced E. globulus trees; Heartwood diameter and height can be modelled with tree diameter and height respectively; Sapwood width is approximately constant within and between coppice and single-stem E. globulus trees.
Coppiced Eucalyptus globulus trees with 18 years in a 2nd rotation were analysed in relation to heartwood, sapwood and bark content taking into account the effect of the initial planting density by using a spacing trial. A total of 25 stumps, with a variable number of stems per stump from 1 to 3, were analysed. Comparison was made to the previous 1st rotation single stem trees, also harvested at 18 years. In the 2nd rotation, the stump density did not significantly affect stem height and diameter, in opposition to the 1st rotation where spacing significantly impacted on tree dimensions. The effect of the initial planting density is somewhat lost in the coppiced stand in relation with i.e. the number of stems per stump. Heartwood was present in all the coppiced trees up to 49.9% of the total tree height and heartwood volume amounted to 38.9–51.7% of the total tree volume. Within the tree, heartwood content decreased from the base upwards, representing, on average, 54.1% at the base and decreasing to 5.1% at 15.3 m. The sapwood width remained relatively constant with an average radial width of approximately 2 cm. The average stem bark content of coppiced trees was 17.4% of the total stem volume. The comparison of heartwood and sapwood development in the coppiced trees did not show significant differences to the 1st rotation trees, nor did the initial spacing. Heartwood diameter could be modelled using the tree diameter both for 1st and 2nd rotation trees.
  • Miranda, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal ORCID ID:E-mail: Imiranda@isa.ulisboa.pt
  • Gominho, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal ORCID ID:E-mail: Jgominho@isa.utl.pt (email)
  • Pereira, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal ORCID ID:E-mail: Hpereira@isa.utl.pt
article id 1124, category Research article
Āris Jansons, Mārtiņš Zeps, Juris Rieksts-Riekstiņš, Roberts Matisons, Oskars Krišāns. (2014). Height increment of hybrid aspen Populus tremuloides x P. tremula as a function of weather conditions in central part of Latvia. Silva Fennica vol. 48 no. 5 article id 1124. https://doi.org/10.14214/sf.1124
Highlights: Intra-annual height growth of hybrid aspen was monitored; Clones with early leaf flushing dates showed faster height growth; Height growth was generally controlled by temperature; Fast-growing hybrids were more robust to weather conditions than slow-growing ones; Potential evapotranspiration (moisture regime) negatively affected height growth of clones with delayed phenology.
Height growth of young hybrid aspen (Populus tremula L. × P. tremuloides Michx.) was studied in relation to weather conditions. Height of clones with different leaf flushing phenology (early, intermediate and late) was monitored during the growing periods of 2010 and 2011 in a plantation established on former agricultural land. Mean daily height increment (HI) was calculated. Multiple linear regression was used to determine which weather factors (variables) had significant effect on HI. Mean seasonal height growth (mean seasonal HI) between clones (groups) was compared by ANOVA. In both years, HI was significantly higher for clones with early and intermediate leaf flushing compared to clones with late leaf flushing. The effect of weather factors also differed between clones according to their leaf flushing phenology; it was the weakest for HI of clones with early leaf flushing compared to clones with intermediate and late leaf flushing. Mean temperature was the main factor, which positively affected HI of all clones, suggesting that warmer climate might be beneficial for height growth of young hybrid aspen in Latvia. Nevertheless, significant negative relationship between HI and potential evapotranspiration (PET) was observed for clones with delayed leaf flushing, suggesting negative effect of increasing variability of precipitation on growth. Thus, the differences in height growth intensity might be related to growth sensitivity to weather conditions. On the other hand, such differences in height growth between clones might be caused by competition (i.e. with herbs), as trees with early leaf flushing might conquer more resources and become more robust against the environmental fluctuation.
  • Jansons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: aris.jansons@silava.lv
  • Zeps, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: martins.zeps@silava.lv
  • Rieksts-Riekstiņš, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: Juris.Riekstins@silava.lv
  • Matisons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: robism@inbox.lv (email)
  • Krišāns, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: oskars.krisans@silava.lv
article id 1176, category Research article
Batoul Al-Hawija, Viktoria Wagner, Monika Partzsch, Isabell Hensen. (2014). Germination differences between natural and afforested populations of Pinus brutia and Cupressus sempervirens. Silva Fennica vol. 48 no. 4 article id 1176. https://doi.org/10.14214/sf.1176
Highlights: Silvicultural practices of raising and outplanting seedlings yielded contrasting outcomes in our species; Afforested Pinus brutia populations acquired ability to tolerate drought stress at intermediate and hot temperatures compared to natural populations, which may indicate local adaptation; Natural Cupressus sempervirens populations showed higher salt-tolerance than afforested populations; Seed germination was optimal under intermediate temperatures and deionized water for both species.
In afforestation, silvicultural processes of raising and planting seedlings under certain conditions can yield contrasting outcomes in tree stock performance. Moderate nursery conditions may select against stress tolerance whereas planting seedlings in stressful environments at afforestation sites may select for higher stress tolerance compared to natural populations. We compared germination performance between natural and afforested populations of Pinus brutia Ten. subsp. brutia and Cupressus sempervirens L. var. horizontalis (Mill.) under differing stress treatments. Seeds were collected from both natural stands and from afforested populations outside the natural distribution range, in Syria. Cold, intermediate and hot temperature regimes were simulated (8/4 °C, 20/10 °C and 32/20 °C) along with cold stratification, drought stress (–0.2 and –0.4 MPa), salt stress (50 and 100 mMol l–1), and deionized water (control) conditions. In addition, we tested the effects of seed weight and climatic conditions on seed germination. In general, intermediate temperatures were optimal for both population types. Afforested P. brutia populations outperformed natural ones under drought stress levels at hot and/or intermediate temperatures. Conversely, in C. sempervirens, cold stratification at all temperatures and higher salt stress at intermediate temperatures significantly decreased germination in afforested populations. Seed weight did not significantly affect germination percentages, which were however significantly negatively related to annual precipitation in P. brutia, and to annual temperature in C. sempervirens. We infer that silvicultural processes led to divergent outcomes in our species: local adaptation to drought stress and hot temperatures in afforested P. brutia populations and lower salt-stress tolerance in C. sempervirens.
  • Al-Hawija, Martin-Luther-University Halle-Wittenberg, Institute of Biology/Geobotany and Botanical Garden, Am Kirchtor 1, D-06108 Halle/Saale, Germany ORCID ID:E-mail: batoulh@gmail.com (email)
  • Wagner, Department of Botany and Zoology, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic ORCID ID:E-mail: wagner@sci.muni.cz
  • Partzsch, Martin-Luther-University Halle-Wittenberg, Institute of Biology/Geobotany and Botanical Garden, Am Kirchtor 1, D-06108 Halle/Saale, Germany ORCID ID:E-mail: monika.partzsch@botanik.uni-halle.de
  • Hensen, Martin-Luther-University Halle-Wittenberg, Institute of Biology/Geobotany and Botanical Garden, Am Kirchtor 1, D-06108 Halle/Saale, Germany & German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany ORCID ID:E-mail: isabell.hensen@botanik.uni-halle.de
article id 1064, category Research article
Back Tomas Ersson, Urban Bergsten, Ola Lindroos. (2014). Reloading mechanized tree planting devices faster using a seedling tray carousel. Silva Fennica vol. 48 no. 2 article id 1064. https://doi.org/10.14214/sf.1064
Highlights: Seedling reloading onto the Bracke Planter crane-mounted planting device was twice as fast with the MagMat tray-wise-loaded carousel as today’s seedling-wise-loaded carousel; Tray-wise reloading combined with deplugging seedlings from suitable cultivation trays has the potential to be an efficient and robust way to feed seedlings on any type of tree planting machine.
On Nordic clearcuts, today’s tree planting machines produce high-quality but costly regenerations. Much of this high cost is attributable to the planting machines’ low productivity. One promising way of raising productivity is to lessen the time spent manually reloading seedlings onto the carousels of crane-mounted planting devices. Using MagMat, a carousel test-rig designed by engineering students, we studied how much faster tray-wise seedling reloading is on the Bracke Planter compared to reloading with today’s seedling-wise-loaded carousel. The MagMat test-rig held eight Hiko cultivation trays from which seedlings were deplugged individually and dropped into the planting tube. The time study confirmed that seedling reloading was on average twice as fast with MagMat compared to today’s seedling carousel, thereby increasing assumed planting machine productivity by 8–9% depending on the planting device used. MagMat’s cost-efficiency was analysed to be particularly reliant on its added investment cost, mechanical availability and how quickly trays can be switched automatically. Nevertheless, MagMat’s field performance illustrated the overall potential of tray-wise loading compared to piecewise seedling loading for increasing the productivity of crane-mounted planting devices. Also, deplugging proved to be a reliable method of extracting seedlings from the rigid, copper-painted Hiko cultivation trays even when performed at the excavator’s boom-tip during mounding work. We conclude that, rather than piecewise seedling loading, tray-wise loading combined with deplugging seedlings from suitable cultivation trays is a reliable and much more time-efficient method to feed seedlings on probably any type of tree planting machine.
  • Ersson, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden ORCID ID:E-mail: back.tomas.ersson@slu.se (email)
  • Bergsten, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden ORCID ID:E-mail: urban.bergsten@slu.se
  • Lindroos, Department of Forest Biomaterials and Technology, SLU, SE-90183 Umeå, Sweden ORCID ID:E-mail: ola.lindroos@slu.se
article id 1002, category Research article
Pentti Niemistö. (2013). Effect of growing density on biomass and stem volume growth of downy birch stands on peatland in Western and Northern Finland. Silva Fennica vol. 47 no. 4 article id 1002. https://doi.org/10.14214/sf.1002
Highlights: The thinning response in young downy birch stands was low and the mortality of merchantable stems was tolerable even in dense unthinned thickets during the rotation of 50 years; The production of above-ground woody biomass and stem volume or even the production of pulpwood increased with stand density, with these values being greatest for unthinned or very lightly thinned plots.
The objective of the study was to ascertain the relationship of thinning intensity of downy birch (Betula pubescens Ehrh.) stands with height, crown, and diameter development as well as pulpwood, stem volume, and biomass increment using long-term (20−30 years) field experiments. Diameter growth of birches increased with thinning intensity during the first 15 years from thinning in all development phases, though after that it did so only for the youngest stands. The thinning response was low. Thinning intensity had no influence on increase in height. In terms of stem volume with bark, the mortality in unthinned stands during the study period was 30–45 m3 ha-1. The mean stem number in unthinned birch thickets fell from 25 000 ha-1 at a dominant height of 7 m to 3000 ha-1 at 18 m. The stem volume increment over the first 15 years was highest (5–6 m3 ha-1 a-1) on the very lightly thinned or unthinned plots, but later there was no significant difference between initial thinning intensities. The maximum above-ground leafless biomass (over 100 Mg ha-1) was achieved on very lightly thinned plots. Also, the total production (including thinning removal) of biomass or stem volume or even the production of pulpwood increased with stand density, with these values being greatest for very lightly thinned or unthinned plots. During 50-year rotation, the highest leafless above-ground biomass production was 2.5 Mg ha-1 a-1 as a mean value from the experiments. The highest mean annual production of pulpwood (d > 6.5 cm) was 3.2 m3 ha-1 a-1, and, in practice, no saw timber or veneer timber was produced, because of the small size and low quality of the stems. A thinning in downy birch stands increased slightly the size of stems to be removed in future cuttings, but with exception for very light thinning it decreased the production of biomass and merchantable wood.
  • Niemistö, Finnish Forest Research Institute, Parkano Unit, FI-39700 Parkano, Finland ORCID ID:E-mail: pentti.niemisto@metla.fi (email)
article id 958, category Research article
Back Tomas Ersson, Linus Jundén, Urban Bergsten, Martin Servin. (2013). Simulated productivity of one- and two-armed tree planting machines. Silva Fennica vol. 47 no. 2 article id 958. https://doi.org/10.14214/sf.958
Highlights: Using discrete-event simulation and detailed terrain and machine models, the productivities of excavator-based one- and two-armed tree planting machines were simulated; The machines’ arms were equipped with one-and two-headed planting devices; Two planting heads per arm rather than two arms per base machine is better for increasing the productivity of intermittently advancing planting machines on Nordic clearcuts.
To increase mechanized planting, planting machine productivity must increase in order to improve cost-efficiency. To determine if excavators with two crane arms could potentially help to increase planting machine productivity under Nordic clearcut conditions, we modelled one-armed and semi-automated two-armed excavators with one- and two-headed planting devices. Using a recently developed tool for discrete-event simulation, these machine models then mounded and planted seedlings on terrain models with moraine soil having various frequencies of obstacles (stumps, roots and stones). Compared to if the two heads were mounted pairwise on only one arm, the results showed that productivity did not increase if two planting heads were attached individually to two separate crane arms. But productivity did increase if the planting machine had four planting heads mounted pairwise on two separate arms. However, despite assuming automated mounding and crane motion between planting spots, the two-armed, four-headed model never achieved high enough productivity levels to make it more cost-efficient than one-armed machines. The simulations illustrate that our terrain models generate realistic root architecture and boulder content distributions in moraine soil, while our machine models functionally describe mechanized planting work. Based on our assumptions, we conclude that further development work on two-armed excavator-based planting machines for Nordic clearcut conditions is not warranted. Our simulations reveal that increasing the number of planting heads per crane arm rather than number of crane arms per base machine offers the greatest potential to raise the productivity of intermittently advancing planting machines.
  • Ersson,  Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: back.tomas.ersson@slu.se (email)
  • Jundén,  UMIT Research Lab, Umeå University, SE-901 87 Umeå, Sweden ORCID ID:E-mail: linus.junden@gmail.com
  • Bergsten,  Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, SE-901 83 Umeå, Sweden ORCID ID:E-mail: urban.bergsten@slu.se
  • Servin,  UMIT Research Lab, Umeå University, SE-901 87 Umeå, Sweden ORCID ID:E-mail: martin.servin@physics.umu.se
article id 928, category Research article
Rune Simonsen. (2013). Optimal regeneration method – Planting vs. natural regeneration of Scots pine in northern Sweden. Silva Fennica vol. 47 no. 2 article id 928. https://doi.org/10.14214/sf.928
Highlights: Two regeneration methods were modelled on stand level and optimised numerically to maximise present value for a range of site indexes and locations; Natural regeneration was optimal in most cases; Planting was optimal for high site indexes, low rate of seedling mortality and for low discount rates; Using genetically improved plant material greatly shifts the preference towards planting
In this study the profitability of regenerating Scots pine (Pinus sylvestris L.) was examined for two methods; planting and natural regeneration with seed trees. The methods were modelled on stand level and optimised numerically using nonlinear optimisation. The analysis includes 7 site indexes, 16 to 28 expressed as dominant height in meters at an age of 100 years; and 8 localities in northern Sweden distributed on two latitudes, 60°N and 64°N and four altitudes, 100 to 400 m.a.s.l. Furthermore, two scenarios of genetically improved planting material were examined. The results show that the optimal choice of regeneration method depends on the location, site index and discount rate. Considering the same genetic regeneration material, natural regeneration was the optimal method for most of the evaluated sites. Planting was optimal only for stands of high site index and low rate of seedling mortality, which is associated with localities on low altitudes. The break even site index, where the two methods yielded the same net present value, was 27 on average (25 to 28). The choice between the two regeneration methods was found to be more economically important when the discount rate was low and for low site indexes. The option of using genetically improved plant material shift the preference towards planting. Thus, the two levels of genetic gain of +4% and +10% to maximum mean annual increment resulted in an average break even site index of 25 and 21 respectively.
  • Simonsen, Department of Forest Economics, SLU, SE-901 83 Umeå, Sweden ORCID ID:E-mail: rune.simonsen@slu.se (email)
article id 912, category Research article
Heidi Hallongren, Juho Rantala. (2012). Commercialisation and international market potential of Finnish silvicultural machines. Silva Fennica vol. 46 no. 4 article id 912. https://doi.org/10.14214/sf.912
Recently, the need to mechanise silvicultural operations has increased in the Nordic countries. While several new machine concepts have been developed, the manufacture of silvicultural devices remains at the market introduction stage. Information is required in support of existing and forthcoming Finnish small-scale producers of silvicultural devices, who wish to commercialise and further market their innovations in domestic and export markets. The aim of this study was to identify the opportunities, challenges and market potential of business activities that develop in connection with device or machine production. Small-scale Finnish manufacturers of silvicultural devices, Finnish large-scale harvester manufacturers and international silvicultural experts participated in the study. The results show that participant groups have varying opinions of cooperation methods and export activities, as well as of the export markets with the best potential. According to international silvicultural experts, mechanised planting and pre-commercial thinning have the greatest potential worldwide. However, demand for mechanised pre-commercial thinning and planting has been mainly confined to the Nordic countries. For a foreign firm marketing a new silvicultural machine concept, the most important customers and cooperation partners are locally operating forest firms, machine contractors and research organisations. The results of the study provide a useful overview of the current state of silvicultural device manufacturing in Finland.
  • Hallongren, Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: heidi.hallongren@metla.fi (email)
  • Rantala, Metsä Group, Tampere, Finland ORCID ID:E-mail: juho.rantala@metsagroup.com
article id 114, category Research article
Roy V. Rea. (2011). Impacts of moose (Alces alces) browsing on paper birch (Betula papyrifera) morphology and potential timber quality. Silva Fennica vol. 45 no. 2 article id 114. https://doi.org/10.14214/sf.114
Although moose browsing effects on the growth and morphology of birch are well studied, effects of moose browsing on potential timber quality of birch have received little attention. Here, an assessment was made of the impacts of moose (Alces alces L.) damage to Paper Birch (Betula papyrifera Marsh.) trees from a 20-year old clear cut area in a sub-boreal spruce forest within the Aleza Lake Research Forest, near Prince George, British Columbia, Canada. Specifically, differences in overall tree architecture and in the internal characteristics of trees that had been severely damaged and suppressed by moose winter browsing were compared to birch trees that had not been damaged by moose in this way and were considered free-to-grow. The average stem diameter, number of annular growth rings, and height of stem breaks made by moose on suppressed birches at the point of breakage was 17.9 ± 6.6 mm, 4.6 ± 1.2, and 141.8 ± 32.0 cm, respectively. Stem diameters and the heights above-the-ground of stem breaks made by moose during sequential breakage events were not significantly different (all p ≥ 0.05) from one another. Decay was significantly (all p ≤ 0.001) more extensive in trees where branches had been broken off by moose than in trees with no breaks or where breaks were from unknown agents. Suppressed birches were significantly (p = 0.048) more exposed (farther from their nearest tree neighbor) when compared to birches that were free-to-grow. The distance from birch trees to species-specific neighbors (of any species) did not differ (all p ≥ 0.05) between suppressed and free-to-grow birches. Suppressed birches damaged from intense browsing and stem breakage were significantly (≤ 0.001) farther away from other birches showing signs of slight to moderate browsing than free-to-grow birches were from similar conspecifics. Because moose appear to impact the potential wood quality of birch, forest managers should consider the impacts that browsing and stem breakage can have on birch timber where these trees co-occur with and are eaten by moose.
  • Rea, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada V2N 4Z9 ORCID ID:E-mail: reav@unbc.ca (email)
article id 112, category Research article
Mike R. Saunders, Shawn Fraver, Robert G. Wagner. (2011). Nutrient concentration of down woody debris in mixedwood forests in central Maine, USA. Silva Fennica vol. 45 no. 2 article id 112. https://doi.org/10.14214/sf.112
Both nutrient concentrations and pre- and post-harvest pool sizes were determined across down woody debris decay classes of several hardwood and softwood species in a long-term, natural disturbance based, silvicultural experiment in central Maine. Concentrations of N, P, Ca, Mg, Cu, Fe, and Zn generally increased 2- to 5-fold with increasing decay class. Concentrations of Mn, Al and B did not differ among decay classes, while K decreased by 20–44% from decay class 1 to class 4. C:N-ratios declined with increasing decay class, while N:P-ratios increased from decay class 1 to 2 and then plateaued with further decay. Within decay classes, softwoods generally had lower nutrient concentrations and higher C:N-ratios than hardwoods; N:P-ratios did not differ between hardwoods and softwoods. Although gap harvesting increased the size of the overall down woody debris nutrient pools, mostly through a large pulse of decay class 1 material, harvesting generally reduced the nutrients held in advanced decay classes. Pre-harvest down woody debris pools for N, P, K and Ca were 11.0, 0.6, 2.1 and 21.1 kg ha–1, respectively, while postharvest were 20.0, 1.3, 6.2 and 46.2 kg ha–1, respectively. While the gap-based silvicultural systems sampled in this study doubled the size of the pre-harvest, downed woody debris nutrient pools, the post-harvest pools were estimated to be only 3.2–9.1% of aboveground nutrients.
  • Saunders, Department of Forestry and Natural Resources, Purdue University, 715 State Street, West Lafayette, IN, USA ORCID ID:E-mail: msaunder@purdue.edu (email)
  • Fraver, USFS Northern Research Station, Grand Rapids, MN, USA ORCID ID:E-mail:
  • Wagner, School of Forest Resources, University of Maine, Orono, ME, USA ORCID ID:E-mail:
article id 125, category Research article
Juho Rantala, Tiina Laine. (2010). Productivity of the M-Planter tree-planting device in practice. Silva Fennica vol. 44 no. 5 article id 125. https://doi.org/10.14214/sf.125
Need to mechanise tree-planting work have recently increased for many reasons. The newest planting and soil scarification device performing work in Nordic forests is the Finnish M-Planter. This study aims to clarify M-Planter’s productivity in practice and show how various factors affect it. The follow-up data set covers 607 work shifts, of 13 operators with, in total, five M-Planters. The average productivity figures for the operators were 143 and 169 seedlings per effective working hour during the first and second planting season, respectively. Overall, the measured average productivity was 34.2% lower than that observed in an earlier work study of the M-Planter based on an experimental study design. On average, the operators learned to use the combination of the M-Planter and a base machine more efficiently while their experience in using it increased during the follow-up. Increasing number of stones and stumps as well as a thicker humus layer decreased productivity of the M-Planter. The study concludes that utilisation of the full productivity potential of the M-Planter requires not only good operators but also development of the whole planting service supply chain.
  • Rantala, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: juho.rantala@metla.fi (email)
  • Laine, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail:
article id 158, category Research article
Ville Hallikainen, Mikko Hyppönen, Leena Pernu, Jouni Puoskari. (2010). Family forest owners’ opinions about forest management in northern Finland. Silva Fennica vol. 44 no. 2 article id 158. https://doi.org/10.14214/sf.158
Forest management guidelines changed at the end of the 1990’s in Finland. Biodiversity, visual landscape, water systems, and different forms of forest use are now better taken into account. The objectives, outdoor recreation motives, and attitudes towards the present forest management activities of the non-industrial private forest owners called family forest owners in this article, whose forest holdings are located in northern Finland, were studied. In addition, a forest owner typology based on the above-mentioned motives, objectives, and attitudes was created, and the relationship between the typology and the forest owners’ background was tested. Principal component analysis, log-linear models, canonical correlations, and K-means cluster analysis were used in the data analysis. The results showed that especially commercial timber production, but also multiple-use forestry, is important for forest owners. Non-timber products such as game, berries, and forest mushrooms were considered more important than biodiversity, conservation of endangered species, tourism, and reindeer herding. The current, more ecological forest management activities were widely accepted by the owners. The changes had been perceived in the forest management activities. Close relationships were found between the objectives, attitudes and motives of the forest owners. Those owners who emphasized ecological tourism and multiple-use forestry, more frequently accepted detailed conservation and other “softer” management methods than those who emphasized commercial timber production. Typologies, called conservationists, timber producers, and multi-objective forest owners, were identified. Forest owner’s education and source of income were closely related to their typology. Highly educated forest owners and those who gained their money from tourism belonged to the groups named conservationists or multi-objective owners, whereas those who lived on forestry income represented timber producers.
  • Hallikainen, Finnish Forest Research Institute, Eteläranta 55, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: ville.hallikainen@metla.fi (email)
  • Hyppönen, Finnish Forest Research Institute, Eteläranta 55, FI-96301 Rovaniemi, Finland ORCID ID:E-mail:
  • Pernu, Finnish Forest Research Institute, Eteläranta 55, FI-96301 Rovaniemi, Finland ORCID ID:E-mail:
  • Puoskari, Finnish Forest Research Institute, Eteläranta 55, FI-96301 Rovaniemi, Finland ORCID ID:E-mail:
article id 466, category Research article
Ilkka Korpela, Tuukka Tuomola, Timo Tokola, Bo Dahlin. (2008). Appraisal of seedling stand vegetation with airborne imagery and discrete-return LiDAR – an exploratory analysis. Silva Fennica vol. 42 no. 5 article id 466. https://doi.org/10.14214/sf.466
The potential for combined use of airborne discrete-return LiDAR and digital imagery in the classification and measurement of common seedling stand vegetation was examined in southern Finland (61°50’N, 24°20’E). Classification was based on spectral and textural image features in addition to geometric and radiometric features of the LiDAR. The accuracy of leaf-on, LiDAR-based terrain elevation models was tested as well as the accuracy of LiDAR in the measurement of vegetation heights. LiDAR-based canopy height and the range-normalized intensity of the LiDAR were strong explanatory variables in vegetation classification. Interspecies variation was observed in the height measurement accuracy of LiDAR for different tree, shrub and low vegetation canopies. Elevation models derived with 1–15 pulses per m2 showed an inherent noise of app. 15–25 cm, which restricts the use of LiDAR in regeneration assessment of very young stands. The spatial pattern of the competing vegetation was reproduced in classification-based raster surfaces, which could be useful in deriving meaningful treatment proposals.
  • Korpela, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail: ilkka.korpela@helsinki.fi (email)
  • Tuomola, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail:
  • Tokola, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail:
  • Dahlin, University of Helsinki, Dept of Forest Management, P.O. Box 27, FI-00014 University of Finland ORCID ID:E-mail:
article id 407, category Research article
Soili Kojola, Timo Penttilä, Raija Laiho. (2004). Impacts of different thinning regimes on the yield of uneven-structured Scots pine stands on drained peatland. Silva Fennica vol. 38 no. 4 article id 407. https://doi.org/10.14214/sf.407
Drained peatlands in northern Europe comprise more than 10 million ha of forestland and thus constitute a considerable production potential in forestry. Much of this area consists of stands dominated by Scots pine and close to maturity regarding commercial thinning. The trees within these stands typically vary in terms of age, size, and growth rate. The impacts of silvicultural cuttings on these uneven-structured stands are inadequately known. We simulated the impacts of a control regime with no thinnings, and three different thinning regimes, involving different thinning intensities, on the development of fifteen pine-dominated stands in Finland. The simulations started from the first thinnings and were continued until regeneration maturity. The predicted total yields ranged from 244 to 595 m3 ha–1, depending on site and thinning regime. The highest total yields were observed for the control regime in which 18–38% of the yield was, however, predicted to self-thin by the end of the simulation. Thus, the differences in the yields of merchantable wood were fairly small among the compared regimes. However, the regimes involving thinnings generally needed less time than the control regime to reach regeneration maturity. The mean annual increment of total stem volume was at its highest in the control regime. The highest mean annual increment of merchantable wood was obtained in the regime involving two moderate thinnings, but excluding the most low-productive sites where thinnings did not increase the yield of merchantable wood.
  • Kojola, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail: soili.kojola@metla.fi (email)
  • Penttilä, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Laiho, University of Helsinki, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:
article id 404, category Research article
William L. Mason, Colin Edwards, Sophie E. Hale. (2004). Survival and early seedling growth of conifers with different shade tolerance in a Sitka spruce spacing trial and relationship to understorey light climate. Silva Fennica vol. 38 no. 4 article id 404. https://doi.org/10.14214/sf.404
Alternative silvicultural systems to clearfelling are being adopted in Great Britain as a means of increasing the species and structural diversity of conifer plantation forests. One area where knowledge is lacking is the critical level of below-canopy light for survival and growth of young seedlings. This was investigated by planting seedlings of European larch Larix decidua (Mill.), Scots pine Pinus sylvestris L., Sitka spruce Picea sitchensis (Bong.(Carr.)), Douglas fir Pseudotsuga menziesii (Mirb.(Franco.)), and western hemlock Tsuga heterophylla (Raf. (Sarg.)) in a Sitka spruce plantation thinned to 3 different spacings. The incident light intensity beneath the canopy ranged from about 2 to over 60 per cent of full light. Planting in an adjoining open area provided an indication of growth under full light. Growth and survival of these seedlings were followed for 4 growing seasons. The highest seedling survival was found under the widest spacing and declined with closer spacing and lower light intensity. Only Douglas fir and western hemlock seedlings survived at the closest spacing, and in low percentages. The tallest seedlings of each species were found in the open grown conditions but survival was variable due to increased weed competition. Species-specific growth responses showed little difference under high light conditions but performance at low light was generally consistent with shade tolerance rankings in the literature except that Sitka spruce shade tolerance was slightly lower than expected. Minimum light requirements for these species increased from 10 to 30 per cent of full light with decreasing shade tolerance. Other studies of incident light in Sitka spruce plantations indicated that target basal areas in the range 25–30 m2 ha–1 are required if these light conditions are to be met, which suggests an irregular shelterwood system with frequent interventions should be favoured.
  • Mason, Forest Research, Northern Research Station, Roslin, Midlothian, Scotland, UK, EH25 9SY ORCID ID:E-mail: bill.mason@forestry.gsi.gov.uk (email)
  • Edwards, Forest Research, Northern Research Station, Roslin, Midlothian, Scotland, UK, EH25 9SY ORCID ID:E-mail:
  • Hale, Forest Research, Northern Research Station, Roslin, Midlothian, Scotland, UK, EH25 9SY ORCID ID:E-mail:
article id 494, category Research article
Antero Varhimo, Soili Kojola, Timo Penttilä, Raija Laiho. (2003). Quality and yield of pulpwood in drained peatland forests: pulpwood properties of Scots pine in stands of first commercial thinnings. Silva Fennica vol. 37 no. 3 article id 494. https://doi.org/10.14214/sf.494
The inherent structural dynamics of drained peatland forests may result in a great variation in various wood and fiber properties. We examined variation in fiber and pulp properties i) among stands, ii) among trees within stands, and iii) within trees in young stands dominated by Scots pine (Pinus sylvestris L.). The stands, selected to cover a maximal range of the potential variation, were all at a stage of development where the first commercial thinnings would be feasible. Differences in the processability of the thinning removals were small. In similar kraft cooking conditions, a 5-unit variation in the kappa number of unbleached pulp was observed among the stands. Stand origin had no effect on pulp bleaching. The wood formed prior to drainage had a higher density, shorter fibers, was slightly slower delignified by cooking, and its yield was slightly lower than that of post-drainage wood. These properties, except for high density, are typical for juvenile wood in general, and at stand level they did not correlate with the proportion of pre-drainage wood. When the variation in fiber and pulp properties was broken down into its components, most of it was derived from tree-level in all the cases. On average, the fiber and pulp properties did not differ from those observed for first-thinning pulpwood from upland sites. Consequently, peatland-grown pulpwood may be mixed with other pulpwood in industrial processes. It would probably be best suited as the raw material for pulps with high bonding requirements, e.g. in the top ply of multi-ply board grades or in some specialty grades.
  • Varhimo, KCL, P.O. Box 70, FIN-02151 Espoo, Finland ORCID ID:E-mail: antero.varhimo@kcl.fi (email)
  • Kojola, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Penttilä, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland ORCID ID:E-mail:
  • Laiho, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail: raija.laiho@helsinki.fi
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 663, category Research article
Lennart Moberg. (1999). Variation in knot size of Pinus sylvestris in two initial spacing trials. Silva Fennica vol. 33 no. 2 article id 663. https://doi.org/10.14214/sf.663
The objective of this study was to investigate the variation in internal knot size of Scots pine (Pinus sylvestris L.) stems sampled from mature permanent plots, and for which the silvicultural history was known. It was based on a sample of mature trees removed from two different spacing trials representing a moderate and high site index. Knot size was measured with non-destructive methods using a CT-scanner and digital image analysis. Initial spacing varied between 0.75 and 3 m on the high site-index trial and between 1.5 and 2.5 m on the moderate site-index trial. Wider initial spacing on the high site index resulted in larger knots near the base of the stem. However, due to successive thinnings which gradually equalised stand density among plots, the difference between most plots was less further up in the stems. The effect of silvicultural regime was much more limited on the lower site index. Within-stand differentiation resulted in a variation of tree diameter (DBH); larger trees had significantly larger knots. Furthermore, knots were larger towards south than towards north in both trials. These results illustrated that, by using non-destructive measurements on trees sampled from permanent research plots, it was possible to simultaneously study the variation of internal knot size at stand (such as site and silviculture effects), within-stand (such as relative tree size) and within-tree levels (such as height and azimuth). However, lack of replication prevented valid statistical inference as to stand-level effects.
  • Moberg, Swedish University of Agricultural Sciences, Department of Forest Management and Products, P.O. Box 7060, S-750 07 Uppsala, Sweden ORCID ID:E-mail: lennart.moberg@sh.slu.se (email)

Category: Review article

article id 693, category Review article
Erik G. Ståhl. (1998). Changes in wood and stem properties of Pinus sylvestris caused by provenance transfer. Silva Fennica vol. 32 no. 2 article id 693. https://doi.org/10.14214/sf.693
Wood properties focused in forest tree breeding should be of economic importance, have a large total variation and a high heritability. The properties of interest are those that influence the strength and durability of sawn products or the amount and properties of pulp produced. The following wood properties are treated: width of the annual ring, juvenile wood, late wood content, heart wood, tracheid dimensions, basic density, stem straightness and branch diameter. The provenance variation in wood properties can be related to differences in growth phenology. In the northern part of distribution P. sylvestris (L.) provenances transferred a few degrees southwards have a high survival and yield but stem wood production is low. Trees from these provenances will be straight and with few spike knots or other injuries. The shoot elongation period will be short and the temperature sum required for wood formation sufficient. Provenances transferred southwards will form thin annual rings, few and thin branches, little early wood, high basic density and slender tracheids with thick cell walls in comparison to local provenances. An example of the effect of alternative transfers on the yield and wood properties is evaluated. In regions with deviating climatic patterns alternative provenance transfer patterns may be better. The objectives of the land owner should influence the provenance choice. The importance of integrating tree improvement with silvicultural management is discussed with reference to spacing.
  • Ståhl, College of Dalarna, CITU Centre for Industrial Technology and Development, S-781 88 Borlänge, Sweden ORCID ID:E-mail: esl@du.se (email)

Category: Research note

article id 1716, category Research note
Nelson Thiffault, Alain Paquette, Christian Messier. (2017). Early silvicultural guidelines for intensive management of hybrid larch plantations on fertile sub-boreal sites. Silva Fennica vol. 51 no. 2 article id 1716. https://doi.org/10.14214/sf.1716
Highlights: Satisfactory growth can be obtained using a wide range of site preparation intensities; There is a net advantage of performing two motor-manual release treatments over a single release; A second release treatment cannot be replaced by more intensive site preparation; Planting depth had no influence on planted seedling growth after 6 years.

Use of fast-growing tree plantations on dedicated areas is proposed as a means of reconciling fibre production with conservation objectives. Success of this approach however requires fine-tuning silvicultural scenarios so that survival and growth are optimized while management and environmental costs are minimized. This is particularly challenging for hybrid larch (Larix × marschlinsii Coaz), a shade-intolerant species planted on fertile sites in Quebec (Canada) where legislation prevents the use of chemical herbicides. In this context, multiple motor-manual release treatments are often required, with high impacts on costs and social issues related to the scarcity of a qualified workforce. We established a split-split-plot design on a recently harvested site to assess the main and interaction effects of mechanical site preparation (MSP) intensity (five modalities of trenching or mounding), motor-manual release scenario (one or two treatments) and planting depth (0–3 cm or 3–10 cm) on hybrid larch seedling growth and survival six years after planting. Mechanical site preparation intensity and planting depth did not influence seedling growth after 6 years. The lack of significant interaction between MSP and release scenarios indicates that these operations should be planned independently. A more intensive MSP treatment cannot replace a second motor-manual release on fertile sites, as proposed to reduce costs. Our results also show the significant advantage of performing two motor-manual release treatments two years apart (the first one early in the scenario), over performing a single treatment. Our study provides silvicultural guidelines for the establishment of high-yield exotic larch plantations.

  • Thiffault, Direction de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs du Québec, 2700 rue Einstein, Québec, QC, Canada G1P 3W8; Centre d’étude de la forêt, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8 ORCID ID: http://orcid.org/0000-0003-2017-6890 E-mail: nelson.thiffault@mffp.gouv.qc.ca (email)
  • Paquette, Centre d’étude de la forêt, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8; Université du Québec à Montréal, Département des sciences biologiques, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8 ORCID ID: http://orcid.org/0000-0003-1048-9674 E-mail: alain.paquette@gmail.com
  • Messier, Centre d’étude de la forêt, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8; Université du Québec à Montréal, Département des sciences biologiques, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8; Institut des Sciences de la Forêt tempérée (ISFORT), 58 rue Principale, Ripon, QC, Canada JOV 1V0 E-mail nelson.thiff ORCID ID:E-mail: christian.messier@uqo.ca

Category: Article

article id 7215, category Article
Mark L. Anderson. (1929). Forest types in Scotland. Acta Forestalia Fennica vol. 34 no. 2 article id 7215. https://doi.org/10.14214/aff.7215

The primeval forests of Scotland were deforested in the Lowlands by the end of 1500th century, and in the end of the 1800th century also the best forests of the more inaccessible Highlands were exploited. The 1800th century witnessed an outburst of afforestation among the private land owners. With help of nursery work and use of exotic species, the work was successful. Silviculture of Scotland would benefit of a reliable method of site classification. The complexity of the geology and topography, and the lack of mature natural stands complicate the establish a forest type classification similar to the one Prof. Cajander has evolved in Finland. The aim is to establish forest site types which include similar types as in Finland, with possibly additional types in the grass-herb series.

Jubileum publication of professor Aimo Kaarlo Cajander.

  • Anderson, ORCID ID:E-mail:
article id 7201, category Article
Lauri Ilvessalo. (1926). Forest research work in Finland : the origins and development of forest research work and a review of the investigations carried out up to date. Acta Forestalia Fennica vol. 31 no. 2 article id 7201. https://doi.org/10.14214/aff.7201

The article is a review of forest research carried out in Finland. The article includes a short review of the origins of forest research in the country and the research institutions in the country. It describes the main studies in different fields of forest research, divided on biological and silvicultural research, forest mensuration and forest policy research, and research on forest utilization.  English translation of the article was published at the same time with an Finnish article. A need for an English summary of the forest research was realized, because the publications have mainly been written in Finnish or German.

  • Ilvessalo, ORCID ID:E-mail:
article id 7200, category Article
Lauri Ilvessalo. (1926). Metsätieteellinen tutkimustoiminta Suomessa : metsätieteellisen tutkimustoiminnan synty ja kehitys sekä yleiskatsaus toimitettuihin tutkimuksiin. Acta Forestalia Fennica vol. 31 no. 1 article id 7200. https://doi.org/10.14214/aff.7200
English title: Forest research in Finland: the origins and development of forest research and a review of the investigations carried out up to date.

The article is a review of forest research carried out in Finland. The article includes a short review of the origins of forest research in the country and the research institutions in the country. It describes the main studies in different fields of forest research, divided on biological and silvicultural research, forest mensuration and forest policy research, and research on forest utilization. An English translation of the article was published at the same time. A need for an English summary of the forest research was realized, because the publications have mainly been written in Finnish or German.

  • Ilvessalo, ORCID ID:E-mail:
article id 5597, category Article
John C. Brissette. (1996). Effects of intensity and frequency of harvesting on abundance, stocking and composition of natural regeneration in the Acadian forest of eastern North America. Silva Fennica vol. 30 no. 2–3 article id 5597. https://doi.org/10.14214/sf.a9242

In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m2 ha-1 for trees ≥1.3 cm diameter at breast height. For the second objective, regeneration was evaluated after four harvests at 5-year intervals. Prior to harvests, the overstory of all the treated stands was dominated by Tsuga canadensis (L.) Carr., Picea spp. A Dietr., and Abies balsamea (L.) Mill. Eleven species or species groups were identified among the regeneration: A. balsamea, T. canadensis, Picea spp., Thuja occidentalis L., Pinus spp. L., Betula papyrifera Marsh., Acer rubrum L., Betula populifolia Marsh., Populus spp. L., Fagus grandifolia Ehrh. and Prunus serotina Ehrh. Regeneration abundance was measured as counts of seedlings or sprouts taller than 15 cm but with diameters less than 1.3 cm at breast height (1.37 m). Regardless of harvest treatment, total regeneration was profuse, ranging from over 25,000 to nearly 80,000 trees ha-1. Regeneration was dominated by conifers with a total angiosperm component of 10 to 52 percent approximately 5 years after harvest and 11 to 33 percent after 10 years. Consequently, in forests of similar species composition, tree regeneration following partial harvests should be sufficiently abundant with an array of species to meet a variety of future management objectives.

  • Brissette, ORCID ID:E-mail:
article id 5540, category Article
Anders Persson. (1994). How genotype and silviculture interact in forming timber properties. Silva Fennica vol. 28 no. 4 article id 5540. https://doi.org/10.14214/sf.a9180

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

  • Persson, ORCID ID:E-mail:
article id 5370, category Article
Harri Rantonen, Juhani Päivänen. (1989). Kasvatusmetsien metsänhoidollinen tila ojitusalueilla puunkorjuun jälkeen. Silva Fennica vol. 23 no. 1 article id 5370. https://doi.org/10.14214/sf.a15529
English title: Silvicultural condition of tree stands after thinning on drained peatlands.

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

The PDF includes an abstract in English.

  • Rantonen, ORCID ID:E-mail:
  • Päivänen, ORCID ID:E-mail:
article id 5362, category Article
Seppo Kellomäki, Heikki Hänninen, Taneli Kolström. (1988). Model computations on the impacts of the climatic change on the productivity and silvicultural management of the forest ecosystem. Silva Fennica vol. 22 no. 4 article id 5362. https://doi.org/10.14214/sf.a15519

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

The PDF includes an abstract in Finnish.

  • Kellomäki, ORCID ID:E-mail:
  • Hänninen, ORCID ID:E-mail:
  • Kolström, ORCID ID:E-mail:
article id 5327, category Article
Yrjö Sepänmaa. (1987). Metsäestetiikka ja metsän estetiikka. Silva Fennica vol. 21 no. 4 article id 5327. https://doi.org/10.14214/sf.a15484
English title: Forstästhetik and forest aesthetics.

Forstästhetik is a programme for forest management, resembling an art manifesto. Forest managers are programme executors. Forest aesthetics is forest investigation from the point of view of beauty. In the case of managed forests, it is possible to ask, what is the manager’s programme and his skill to achieve personal solutions. In forests, the functioning and sustainability of the ecosystem are basic principles affecting all other values. On this basis it is possible to evaluate the competence of taste systems and the logic of their application.

The paper is based on a lecture given in the seminar ‘The forest as a Finnish cultural entity’, held in Helsinki in 1986. The PDF includes a summary in English.

  • Sepänmaa, ORCID ID:E-mail:
article id 5273, category Article
Raymond K. Omwami. (1986). A theory of stumpage appraisal. Silva Fennica vol. 20 no. 3 article id 5273. https://doi.org/10.14214/sf.a15452

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

The PDF includes an abstract in Finnish.

  • Omwami, ORCID ID:E-mail:
article id 4800, category Article
Veli-Pekka Järveläinen. (1969). Metsänhoidolliset mielipiteet ja metsänhoidollinen toiminta maatilametsätaloudessa. Silva Fennica vol. 3 no. 3 article id 4800. https://doi.org/10.14214/sf.a14588
English title: Opinions about silviculture in farm forestry in Finland, and practical steps taken.

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

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

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

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

The PDF includes a summary in English.

  • Järveläinen, ORCID ID:E-mail:
article id 7651, category Article
Raymond K. Omwami. (1988). An economic model underlying the choice of capital intensity in timber production. Acta Forestalia Fennica no. 204 article id 7651. https://doi.org/10.14214/aff.7651

The process of capital accumulation in timber production has been examined in this study. A detailed explanation of new investment in forest industry in terms of productive capacity as the determinant of national forest policy target growing stock and silviculture is presented. The basis of the explanation of forest industry productive capacity was a linear vertically integrated input-output production model. The model was used to derive a macroeconomic equilibrium condition specifying forest sector aggregate demand as an integral part of the national economy. Timber production has been constructed as a state variable system and the Maximum Principle used to derive silvicultural investment criterion. The derivation of the investment criterion was formulated as a dynamic problem in a labour surplus economy with linkage between savings and choice of silvicultural technology defined via income distribution between wages and profit. Maximization of aggregate consumption was specified as the goal of timber production.

By assuming a state of sub-optimal savings rate, it is shown that the real cost of labour is not zero in a labour surplus economy. Because unemployment labour is not a free commodity, it is concluded that capital-intensive silvicultural technology represents an optimal means of maximizing aggregate consumption in labour surplus economy, contrary to the recommendation of social marginal productivity theory.

The PDF includes a summary in Finnish.

  • Omwami, ORCID ID:E-mail:
article id 7636, category Article
Kari Heliövaara, Rauno Väisänen. (1984). Effects of modern forestry on Northwestern European forest invertebrates: a synthesis. Acta Forestalia Fennica no. 189 article id 7636. https://doi.org/10.14214/aff.7636

The effects of modern forestry on northwest European forest invertebrates are summarized and analysed mainly on the basis of published literature. The direct influence of different practices including clear-cutting, thinning, burning-over, ploughing, changes in tree species composition of stands, fertilization, insecticides, pheromones and biological control are discussed from a forest zoological point of view. Also, the indirect effects of general changes in boreal forest dynamics, loss of primeval forests, cessation of natural fires and the dominance of young stands are described. The direct effects of different silvicultural practices on the species composition and diversity of forest invertebrates are usually considered to be striking but transient. However, when large areas are treated, the species associated with primeval forests, especially with the wood composition system in them, as well as the species associated with fires, seem to have drastically declined. In northwest Europe, efficient forestry has not caused such serious pest problems as is known from tropical countries or North America.

The PDF includes a summary in Finnish.

  • Heliövaara, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:
article id 4646, category Article
Paavo Yli-Vakkuri. (1955). Tutkimuksia metsänhoitolautakuntien ja -yhdistysten leimaustoiminnan kehityksestä. Silva Fennica no. 87 article id 4646. https://doi.org/10.14214/sf.a9108
English title: Studies on crop marking of District Forestry Boards and Forest Management Associations.

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

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

The article includes a summary in German.

  • Yli-Vakkuri, ORCID ID:E-mail:
article id 4599, category Article
Polttoainekomitea. (1950). Polttoainekysymys vuonna 1949 : polttoainekomitean mietintö. Silva Fennica no. 67 article id 4599. https://doi.org/10.14214/sf.a9090
English title: The fuel question in 1949.

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

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

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

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

The article includes a summary in English.

  • Polttoainekomitea, ORCID ID:E-mail:
article id 4585, category Article
Erkki K. Kalela. (1948). Luonnonmukainen metsien käsittely. Silva Fennica no. 64 article id 4585. https://doi.org/10.14214/sf.a13987
English title: Ecological forest management.

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

This presentation describes how the natural processes of forests and succession could be utilized in forest management and silviculture.

  • Kalela, ORCID ID:E-mail:
article id 4502, category Article
V. K. Ahola. (1937). Havaintoja viimeaikaisista metsänhoitotöistä valtionmetsissä. Silva Fennica no. 39 article id 4502. https://doi.org/10.14214/sf.a13912
English title: Observations on forest management work in state forests.

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

This presentation describes the forest management work in the state forests.

  • Ahola, ORCID ID:E-mail:
article id 4500, category Article
Erkki Laitakari. (1937). Laatupuun kasvattamisesta. Silva Fennica no. 39 article id 4500. https://doi.org/10.14214/sf.a13910
English title: Production of good quality timber.

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

This presentation describes methods of forest management that lead to production of qood quality timber, needed in the saw industry.

  • Laitakari, ORCID ID:E-mail:
article id 4486, category Article
Martti Tertti. (1937). Metsien luontaisen uudistumisen edistämisestä. Silva Fennica no. 39 article id 4486. https://doi.org/10.14214/sf.a13896
English title: Facilitating natural regeneration.

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

This presentation describes natural regeneration in forests and factors affecting the success of regeneration.

  • Tertti, ORCID ID:E-mail:
article id 4454, category Article
C. C. Böcker. (1929). Om skogars skötsel i Norden. Silva Fennica no. 13 article id 4454. https://doi.org/10.14214/sf.a8987
English title: Silviculture in the Northern countries.

The article gives a review on the history of forest management in the Northern countries. The article concludes that in the Northern Countries with their immense supplies of forest and small demand, because of sparse population, there was no hurry for developing the study of forest economics, as was the case in Central Europe. It was only when the modern wood using industry had revolutionized the marketing conditions, that the opportunity was provided for forest economics to develop. The paper introduces the book ’Om skogarnas skötsel in Norden’ (Silviculture in the Northern Countries) written by a Finn C.C. Böcker. That paper was compiled in behalf of a request of the king of Sweden, King Carl XIV Johan, who offered a price to a person who would draw a scheme for organizing forestry in Sweden, where Finland at that time belonged to. The prize was divided by Böcker and a swede, af Ström.

The PDF includes a summary in Finnish and English and the original text in Swedish.

  • Böcker, ORCID ID:E-mail:
article id 4454, category Article
C. C. Böcker. (1929). Om skogars skötsel i Norden. Silva Fennica no. 13 article id 4454. https://doi.org/10.14214/sf.a8987
English title: Silviculture in the Northern countries.

The article gives a review on the history of forest management in the Northern countries. The article concludes that in the Northern Countries with their immense supplies of forest and small demand, because of sparse population, there was no hurry for developing the study of forest economics, as was the case in Central Europe. It was only when the modern wood using industry had revolutionized the marketing conditions, that the opportunity was provided for forest economics to develop. The paper introduces the book ’Om skogarnas skötsel in Norden’ (Silviculture in the Northern Countries) written by a Finn C.C. Böcker. That paper was compiled in behalf of a request of the king of Sweden, King Carl XIV Johan, who offered a price to a person who would draw a scheme for organizing forestry in Sweden, where Finland at that time belonged to. The prize was divided by Böcker and a swede, af Ström.

The PDF includes a summary in Finnish and English and the original text in Swedish.

  • Böcker, ORCID ID:E-mail:
article id 4442, category Article
Lauri Ilvessalo. (1927). Cultivation of exotic tree species. Silva Fennica no. 4 article id 4442. https://doi.org/10.14214/sf.a8390

Successful cultivation of a tree species outside its natural area of distribution involves that the original climate is similar to that of the area where it will be cultivated. Seeds should be procured from an area, where the climate is most similar to the area of cultivation. In addition, the site requirements should be met. To be worth of cultivation, the exotic tree species should offer advantages over the native species, such as wood quality, higher productivity, modest site requirement, greater endurance against spring frosts and cold in the winter, valuable by-products, resistance against grazing, insects or fungi, or improvement of soil.

In Finland, successful examples are Larix europaea Lam. & A. DC. and Larix sibirica Lebed, which both give better yield than the native species, and have better resistance against decay. In Central Europe, Pseudotsuga mentziesii (Mirb.) Fnanko, Pinus strobus L. and Pinus sitchensis (Bong.) Carriére have proved to be good forest trees. In Hungary, Robinia pseudoacacia L. has become economically important. Eucalyptus spp. have been cultivated in the Mediterranean countries, South America and California.

A summary in Finnish is included in the PDF.

  • Ilvessalo, ORCID ID:E-mail:

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