Current issue: 51(2)

Under compilation: 51(3)

Impact factor 1.470
5-year impact factor 1.788
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Silva Fennica vol. 46 no. 4 | 2012

Category: Research article

article id 913, category Research article
Han Zhang & Joseph Buongiorno. (2012). Markets, government policy, and China's timber supply. Silva Fennica vol. 46 no. 4 article id 913. https://doi.org/10.14214/sf.913
China's domestic demand and exports of wood products are rising rapidly compared to domestic supply. The determinants of timber supply in China were investigated with panel data from 25 provinces from 1999 to 2009. The results indicated that China’s timber supply had responded to both market forces, reflected by timber prices largely determined by world demand and supply, and to government policies expressed by production quotas and the tenure reform on collective forestland. The price elasticity of China’s timber supply was estimated at 0.31±0.12. The inelastic response of production to the quota (0.20±0.02) suggested that government had a limited, though significant, control of timber supply. Other things being equal, the land tenure reform increased timber supply by 18±8 percent, where and when it had been implemented.
  • Zhang, Research Center for Resource Economics and Environment Management, Northwest A&F University. No. 3 Taicheng Road, Yangling, Shaanxi, China 712100 ORCID ID:E-mail:
  • Buongiorno, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, WI 53706, U.S.A. ORCID ID:E-mail: jbuongio@wisc.edu (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 911, category Research article
Marjut Turtiainen, Olli Saastamoinen, Kari Kangas & Matti Vaara. (2012). Picking of wild edible mushrooms in Finland in 1997–1999 and 2011. Silva Fennica vol. 46 no. 4 article id 911. https://doi.org/10.14214/sf.911
This study reports on national survey results concerning mushroom picking in Finland during four separate years: 1997–1999 and 2011. The material was collected by mailed questionnaire surveys amongst Finnish households. The sample size varied from 1858 (in 1998) to 6849 households (in 1997) and the response rates varied from 51% (in 2011) to 70% (in 1999). The results indicate that both the rate of participation in mushroom picking and estimates of the quantities collected varied greatly depending on whether the survey was conducted in a favourable or unfavourable year. In 1998, when the mushroom crop was abundant, a total of 47% of all households were engaged in picking and the total harvest was 16.1 million kg. In 1999, when the crop was poor, the estimates were the lowest (23% and 3.3 million kg, respectively) and in a year with a relatively abundant crop (2011), the estimates were 42% and 15.0 million kg, respectively. Mushrooms were collected mainly for home use, which accounted for 85–90% of the total harvest depending on the year. Only a small proportion of all households (0.3–1.3%) were engaged annually in commercial mushroom picking. In 1997–1999, milk caps formed the major part of the total amount picked (i.e. 37–53% depending on the year), whilst in 2011 their share was approximately one fifth of the total harvest. The results also indicate that the proportion of ceps in commercial picking has increased since the 1990s
  • Turtiainen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: marjut.turtiainen@uef.fi (email)
  • Saastamoinen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: olli.saastamoinen@uef.fi
  • Kangas, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: kari.kangas@uef.fi
  • Vaara, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: matti.vaara@uef.fi
article id 910, category Research article
Gernot Erber, Christian Kanzian & Karl Stampfer. (2012). Predicting moisture content in a pine logwood pile for energy purposes. Silva Fennica vol. 46 no. 4 article id 910. https://doi.org/10.14214/sf.910
Determining the moisture content of naturally dried fuel stock without frequent measuring is a problem still unsolved. Modelling moisture content based on automatically captured meteorological data could provide a solution. An accurate model would allow the drying period and the point of chipping to be optimised. For the experimental study, a metal frame supported by load sensors and loaded with 17 tons of logwood was set up next to a meteorological station. A multiple linear regression model was used to link meteorological and load data to provide a formula for determining the moisture content. The pile dried for a period of 14 months (average temperature of 7.3 °C, a humidity of 81%, and 777 mm of rainfall). The overall moisture content dropped from 50.1% to 32.2%. The regression model, which based on daily means and sums of meteorological parameters, provided a mean deviance from the observed curve of –0.51%±0.71% within the period of investigation. Relative humidity was found to be most important parameter in drying. Increased moisture content resulting from rainfall greater than 30 mm per day reverted back to pre-rainfall values within two to three days, if no other rainfall events followed. Covering the pile would have a positive effect on the drying performance. In terms of economic benefit it could be shown that natural drying is beneficial. Overall this study shows that meteorological data used in site specific drying models can adequately predict the moisture content of naturally dried logwood.
  • Erber, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria ORCID ID:E-mail: gernot.erber@boku.ac.at (email)
  • Kanzian, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria ORCID ID:E-mail: christian.kanzian@boku.ac.at
  • Stampfer, University of Natural Resources and Life Sciences, Peter Jordan-Strasse 82, 1190 Wien, Austria ORCID ID:E-mail: karl.stampfer@boku.ac.at
article id 909, category Research article
Veikko Hiltunen, Mikko Kurttila & Jouni Pykäläinen. (2012). Strengthening top-level guidance in geographically hierarchical large scale forest planning: experiences from the Finnish state forests. Silva Fennica vol. 46 no. 4 article id 909. https://doi.org/10.14214/sf.909
Different planning approaches conclude to different results. The top-down approach allocates resources efficiently from the top-level perspective, while the bottom-up approach provides optimal results for the lower levels. Integrated approach that combines the elements of these two basic approaches provides compromise solutions for decision makers. The aim of this study was to examine potential efficiency improvements in hierarchically structured large scale forest management through increased top-level guidance. The resulting effects on the acceptability of the plans on the lower level were also studied. Large scale planning typically considers forests owned by states, companies and municipalities. In the case study of the Finnish state forests, alternative country level solutions were generated by combining regional forest plans in different ways. The results showed that the currently applied bottom-up approach, which produces regionally optimal management strategies, did not result in the most efficient use of resources on the country level. However, the new country level solutions did not produce huge improvements in the country level objective values compared to the results of the current approach. Furthermore, if country level efficiency improvements were emphasized more, together with wide approval by regional stakeholders and local residents, new kind of interaction and participation between the planning levels and also between the regions would be needed.
  • Hiltunen, Metsähallitus, Viestitie 2, FI-87700 Kajaani, Finland ORCID ID:E-mail: veikko.hiltunen@metsa.fi (email)
  • Kurttila, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: mikko.kurttila@metla.fi
  • Pykäläinen, Finnish Forest Research Institute, Joensuu Unit, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: jouni.pykalainen@metla.fi
article id 908, category Research article
Sattar Ezzati, Akbar Najafi, M. A. Rab & Eric K. Zenner. (2012). Recovery of soil bulk density, porosity and rutting from ground skidding over a 20-year period after timber harvesting in Iran. Silva Fennica vol. 46 no. 4 article id 908. https://doi.org/10.14214/sf.908
Ground-based skidding can have detrimental effects on soil properties trough soil profile disturbance and compaction that can persist for decades. We investigated the recovery of physical properties of disturbed brown soils on four abandoned downhill skid trails in a deciduous mountain forest in northern Iran. The most recent skidding operations had taken place 1–5 yrs, 6–10 yrs, 11–15 yrs, and 16–20 yrs ago, providing a 20-year chronosequence with four 5-year recovery periods. For each recovery period, mean values for soil bulk density (BD), total porosity (TP), macroporosity (MP), soil moisture content (SM), and rut depth (RD) were assessed for three levels of traffic intensity (Primary (PS), Secondary (SS) and Tertiary (TS) skid trails) and two levels of slope gradients (Gentle (G) and Steep (S)) and compared to those in undisturbed (control) areas. Over the 20-year recovery period, PS trails on gentle slopes exhibited mean values that were 35–42% (BD), 3–7% (SM), and 13–19 cm (RD) greater and 18–24% (TP) and 19–28% (MP) lower compared to undisturbed areas; on steep PS trails, values were 40–46% (BD), 2–13% (SM), and 13–21 cm (RD) greater and 23–27% (TP) and 28–35% (MP) lower, respectively. While RD and SM recovered, 20 years was not long enough for the other physical soil properties, particularly on steep slopes. To minimize soil disturbance, skidding should be confined to areas with gentle slopes and alternative harvesting methods such as cable yarding should be used where slope gradients exceed 20%.
  • Ezzati, Department of Forestry and Forest Engineering, Tarbiat Modares University, P.O. Box 64414-356, Iran ORCID ID:E-mail:
  • Najafi, Department of Forestry and Forest Engineering, Tarbiat Modares University, P. Box 64414-356, Iran ORCID ID:E-mail: a.najafi@modares.ac.ir (email)
  • Rab, Soil Physics Future Farming Systems Research Division, Department of Primary Industries, Victoria, Australia ORCID ID:E-mail:
  • Zenner, Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA ORCID ID:E-mail: eric.zenner@psu.edu
article id 907, category Research article
Chunyu Zhang, Yazhou Zhao, Xiuhai Zhao & Klaus von Gadow. (2012). Species-habitat associations in a northern temperate forest in China. Silva Fennica vol. 46 no. 4 article id 907. https://doi.org/10.14214/sf.907
This contribution identifies species-habitat associations in a temperate forest in north-eastern China, based on the assumption that habitats are spatially autocorrelated and species are spatially aggregated due to limited seed dispersal. The empirical observations were obtained in a large permanent experimental area covering 660 x 320 m. The experimental area was subdivided into four habitat types using multivariate regression tree (MRT) analysis. According to an indicator species analysis, 38 of the 47 studied species were found to be significant indicators of the MRT habitat types. The relationships between species richness and topographic variables were found to be scale-dependent, while the great majority of the species shows distinct habitat-dependence. There are 188 potential species-habitat associations, and 114 of these were significantly positive or negative based on habitat randomization. We identified 139 significant associations using a species randomization. A habitat is not a closed system it may be both, either a sink or a source. Therefore, additional to the randomization, the Poisson Cluster Model (PCM) was applied. PCM considers the spatial autocorrelation of species and habitats, and thus appears to be more realistic than the traditional randomization processes. It identified only 37 associations that were significant. In conclusion, the deviation from the random process, i.e. the high degree of species spatial mingling may be explained by persistent immigration across habitats.
  • Zhang, Key Laboratory for Forest Resources & Ecosystem Processes of Beijing, Beijing Forestry University, Beijing 100083, China ORCID ID:E-mail: zcy_0520@163.com (email)
  • Zhao, Department of Landscape Architecture, School of Architecture, Tsinghua University, Beijing 100084, China ORCID ID:E-mail:
  • Zhao, Key Laboratory for Forest Resources & Ecosystem Processes of Beijing, Beijing Forestry University, Beijing 100083, China ORCID ID:E-mail:
  • von Gadow, Faculty of Forestry and Forest Ecology, Georg-August-University Göttingen, Büsgenweg 5, D-37077 Göttingen, Germany ORCID ID:E-mail: KGadow@gwdg.de
article id 906, category Research article
Eivind Meen, Anders Nielsen & Mikael Ohlson. (2012). Forest stand modelling as a tool to predict performance of the understory herb Cornus suecica. Silva Fennica vol. 46 no. 4 article id 906. https://doi.org/10.14214/sf.906
Forest simulation models have been widely used to predict future stand structure. Generally these models do not include the understory vegetation and its response on stand structure change or other environmental factors. Previous simulation studies have shown that stand structure related variables, e.g. basal area, can explain diversity of the forest floor vegetation in boreal forests. We hypothesise that such variables also can be used to explain the performance of understory species and we conceptualise how plant ecology and forest modelling can be combined to predict the performance of understory plants in Norwegian boreal forests. We predict the performance of an understory plant species (Cornus suecica) over time using simulated values of forest variables as input to models expressing the relationship between forest environment variables and plant performance variables (viz. plant height, plant dry weight, number of flowers, number of branches and number of leaves). We also present relationships between plant performance and explanatory variables commonly used in basic ecological research, variables that currently not are readily compatible with forest simulators (e.g. soil chemical variables).We found basal area of canopy trees being the most important explanatory variable explaining C. suecica performance. The performance variable dry weight was predicted by one single model whereas the other performance variables were best predicted by model averaging. Forest simulations for 150 years showed values of plant performance of C. suecica to be reduced during forest succession.
  • Meen, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway ORCID ID:E-mail: eivind.meen@umb.no (email)
  • Nielsen, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway ORCID ID:E-mail:
  • Ohlson, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway ORCID ID:E-mail:
article id 905, category Research article
Katarzyna A. Jadwiszczak, Danuta Drzymulska, Agata Banaszek & Piotr Jadwiszczak. (2012). Population history, genetic variation and conservation status of the endangered birch species Betula nana L. in Poland. Silva Fennica vol. 46 no. 4 article id 905. https://doi.org/10.14214/sf.905
The effective conservation of species requires data on the levels and distribution of genetic diversity within and among populations. In this study, we estimated the genetic variation in three isolated populations of Betula nana in Poland. An analysis of 11 nuclear microsatellites revealed moderate mean heterozygosities (HO=0.556, HE=0.562), low mean number of alleles per locus (A=4.57) and no inbreeding in the total sample. An M-ratio test indicated that each population had experienced a severe bottleneck in the past. Tests for heterozygosity excess revealed that a significant decrease in the numbers of individuals in two populations had occurred quite recently. The large number of private alleles and very restricted number of migrants between populations (Nm=0.35) strongly suggest that genetic drift and geographic isolation are the primary factors responsible for the reduction of genetic variation in the Polish populations of B. nana. We detected two cpDNA haplotypes in the study populations, which can be explained in terms of either the genetic drift acting on the relict localities or a postglacial recolonisation from distinct refugia. Palynological data indicated that one refugium could be located in the Carpathians and their northern foreland. The primary threat to B. nana in Poland is the overgrowth of its habitats by competing species, which has likely resulted in a lack of generative reproduction in the mountain populations.
  • Jadwiszczak, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland ORCID ID:E-mail: kszalaj@uwb.edu.pl (email)
  • Drzymulska, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland ORCID ID:E-mail:
  • Banaszek, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland ORCID ID:E-mail:
  • Jadwiszczak, Institute of Biology, University of Białystok, wierkowa 20B, 15-950 Białystok, Poland ORCID ID:E-mail:

Category: Research note

article id 915, category Research note
Kalle Kärhä. (2012). Comparison of two stump-lifting heads in final felling Norway spruce stand. Silva Fennica vol. 46 no. 4 article id 915. https://doi.org/10.14214/sf.915
The use of stump and root wood chips has increased very rapidly in the 21st century in Finland: in the year 2000, the total consumption of stump wood chips for energy generation was 10 GWh, while in 2010 it was approximately 2 TWh. Metsäteho Oy and TTS Research evaluated two stump-lifting devices for the lifting of Norway spruce (Picea abies) stumps. The productivity and costs of stump lifting were determined. There was one base machine with one operator in the time study. When lifting stumps with a diameter of 30 cm, the effective hour productivity of stump lifting was 11.2 m3 solid over bark (sob)/E0 (4.8 tonD/E0) without site preparation using a Väkevä Stump Processor, and when lifting spruce stumps with a diameter of 40 cm, the productivity was 14.9 m3 sob/E0 (6.5 tonD/E0). When the site preparation (mounding) was integrated into lifting work, the stump-lifting productivity decreased 21–27%. The stump-lifting productivity of the other lifting head (Järvinen) was lower than that of the Väkevä Stump Processor. Some development suggestions for the Järvinen lifting head were presented and discussed. The cost calculations showed that stump-lifting costs are extremely high when stump diameter is less than 20 cm. Therefore, the study recommended a change in the current stump-harvesting guidelines of Finland: The study suggested that all the stumps with a diameter less than 20 cm should be left on the harvesting site.
  • Kärhä, Stora Enso Wood Supply Finland, Talvikkitie 40 C, FI-01300 Vantaa, Finland ORCID ID:E-mail: kalle.karha@storaenso.com (email)
article id 914, category Research note
Ingegerd Backlund & Urban Bergsten. (2012). Biomass production of dense direct-seeded lodgepole pine (Pinus contorta) at short rotation periods. Silva Fennica vol. 46 no. 4 article id 914. https://doi.org/10.14214/sf.914
Lodgepole pine (Pinus contorta) is a fast-growing species that is suitable for producing woody biomass in Nordic countries. Direct seeding of this species is cheaper than planting and creates dense, stable stands. The objective of this study was to quantify the stem volume and biomass production of direct seeded lodgepole pine stands grown under different site conditions with different stem densities, at an age that would permit extensive harvesting of biomass. A circle-plot inventory was performed in 16 of the oldest direct seeded lodgepole pine stands in mid-northern Sweden. Stemwood production of almost 200 m3/ha was achieved on average on the best sites, rising to about 300 m3/ha for the best circle-plots within 30 years of direct seeding despite the fact that pre-commercial thinning was made once or twice. This corresponds to 100 and 140 tons of dry weight biomass/ha, respectively. Higher stand stem densities (≥3000 st/ha) yielded more biomass with only slight reductions in diameter at breast height. The development of stem volume with respect to dominant height in direct seeded stands was becoming comparable to that in planted stands with similar spacing. It therefore seems that there is an unutilized potential for cost-effectively growing lodgepole pine in dense stands for biomass production after direct seeding. It may be possible to devise regimes for short(er) rotation forestry that would yield substantial amount of inexpensive biomass for biorefineries within a few decades.
  • Backlund, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID:E-mail: ingegerd.backlund@slu.se (email)
  • Bergsten, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID:E-mail: urban.bergsten@slu.se

Register
Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content

Your selected articles