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Silva Fennica vol. 54 no. 1 | 2020

Category: Editorial

article id 10333, category Editorial
Matti Maltamo. (2020). Change of the Subject Editor in Silva Fennica. Silva Fennica vol. 54 no. 1 article id 10333. https://doi.org/10.14214/sf.10333
  • Maltamo, University of Eastern Finland, School of Forest Sciences, Joensuu, Finland ORCID ID:E-mail: matti.maltamo@uef.fi (email)
article id 10329, category Editorial
Lars Eliasson. (2020). Forest research and the needs of our stakeholders. Silva Fennica vol. 54 no. 1 article id 10329. https://doi.org/10.14214/sf.10329
  • Eliasson, Skogforsk, The Forestry Research Institute of Sweden, Uppsala Science Park, 751 83 Uppsala, Sweden ORCID ID: https://orcid.org/0000-0002-2038-9864 E-mail: lars.eliasson@skogforsk.se (email)

Category: Research article

article id 10243, category Research article
Laura Pikkarainen, Jaana Luoranen, Antti Kilpeläinen, Teppo Oijala, Heli Peltola. (2020). Comparison of planting success in one-year-old spring, summer and autumn plantings of Norway spruce and Scots pine under boreal conditions. Silva Fennica vol. 54 no. 1 article id 10243. https://doi.org/10.14214/sf.10243
Highlights: In Norway spruce, 84% of all plantings were successful, whereas in Scots pine, the corresponding number was 52%; The major reason for poor planting results was poor work quality; An extended planting season is possible for Norway spruce in southern and central Finland; In Scots pine, there are still large uncertainties in the success of summer and autumn plantings.

In Nordic countries, tree planting of seedlings is mainly performed during spring and early summer. Interest has increased in extending the planting window throughout the unfrozen growing season. This study compared the success of one-year-old spring, summer and autumn plantings in practical forestry in Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in southern and central Finland. Planting success was based on the number of viable seedlings per hectare relative to a species-specific target density. The influence of different factors to poor planting results were determined, including quality of site preparation and planting, and sources of natural damage. Overall, in Norway spruce, 85, 69 and 84% and in Scots pine 53, 55 and 40% of spring, summer and autumn plantings succeeded. In Norway spruce, the planting results were consistent between the southern and central regions, whereas in Scots pine, the success was slightly lower in the south. The poor work quality and a low density of appropriate planting spots, contributed to poor planting results, regardless of planting season, region or tree species. Considering different damages, especially mammal damage contributed to the failure of Scots pine spring plantings, whereas in summer plantings, corresponding single failure reason could not be identified. Based on our findings, extending the planting season of Norway spruce could be recommended in both regions. For Scots pine, there is still significant uncertainty about the success of summer and autumn plantings, partially due to the limited number of plantings available for analyses.

  • Pikkarainen, School of Forest Sciences, University of Eastern Finland, Yliopistonkatu 7, FI-80100 Joensuu, Finland ORCID ID:E-mail: laura.pikkarainen@uef.fi (email)
  • Luoranen, Natural Resources Institute Finland (Luke), Production Systems, Neulaniementie 5, FI-70210 Kuopio, Finland ORCID ID:E-mail: jaana.luoranen@luke.fi
  • Kilpeläinen, School of Forest Sciences, University of Eastern Finland, Yliopistonkatu 7, FI-80100 Joensuu, Finland ORCID ID:E-mail: antti.kilpelainen@uef.fi
  • Oijala, Metsä Group, Metsä Forest, Kuormaajantie 7, FI-40320 Jyväskylä, Finland ORCID ID:E-mail: teppo.oijala@metsagroup.com
  • Peltola, School of Forest Sciences, University of Eastern Finland, Yliopistonkatu 7, FI-80100 Joensuu, Finland ORCID ID:E-mail: heli.peltola@uef.fi
article id 10242, category Research article
Shisheng Long, Siqi Zeng, Falin Liu, Guangxing Wang. (2020). Influence of slope, aspect and competition index on the height-diameter relationship of Cyclobalanopsis glauca trees for improving prediction of height in mixed forests. Silva Fennica vol. 54 no. 1 article id 10242. https://doi.org/10.14214/sf.10242
Highlights: In this study, the effects of slope, aspect and competition index (CI) on the H-DBH relationship were explored and an improved CI was developed and included to improve predictions of Cyclobalanopsis glauca tree height; It was found that the effects were statistically significant and considering slope, aspect and CI for developing the H-DBH models significantly increased the H prediction accuracy.

Diameter at breast height (DBH) and height (H) of trees are two important variables used in forest management plans. However, collecting the measurements of H is time-consuming and costly. Instead, the H-DBH relationship is modeled and used to estimate H. But, ignoring the effects of slope, aspect and tree competition on the H-DBH relationship often impedes the improvement of H predictions. In this study, to improve predictions of Cyclobalanopsis glauca (Thunb.) Oerst. tree H in mixed forests, we compared eleven H-DBH models and examined the influence of slope and aspect on the H-DBH relationship using 426 trees. We then improved Hegyi competition index and explored its effect on the H predictions by including it in the selected models. Results showed 1) There were statistically significant effects of slope and aspect on the H-DBH relationship; 2) The log transformation and exponential model performed best for sunny- and shady-steep, respectively, and the Gompertz’s model was optimal for both sunny- and shady-gentle; 3) Compared with the whole dataset, the division of the data into the slope and aspect sub-datasets significantly reduced the RMSE of H predictions; 4) Compared with the selected models without competition index, adding the original Hegyi and improved Hegyi_I into the models improved the H predictions but only the models containing the improved Hegyi_I significantly increased the prediction accuracy at the significant level of 0.1. This study implied that modeling the H-DBH relationship under different slopes and aspects and including the improved Hegyi_I provided the great potential to improve the H predictions.

  • Long, Faculty of Forestry, Central South University of Forestry and Technology, Changsha, Hunan 410004, China ORCID ID:E-mail: shisheng3604@21cn.com
  • Zeng, Faculty of Forestry, Central South University of Forestry and Technology, Changsha, Hunan 410004, China ORCID ID:E-mail: zengsiqi@21cn.com
  • Liu, Faculty of Forestry, Central South University of Forestry and Technology, Changsha, Hunan 410004, China ORCID ID:E-mail: liufl680@126.com
  • Wang, Research Center of Forestry Remote Sensing & Information Engineering, Central South University of Forestry and Technology, Changsha 410004, China; Department of Geography and Environmental Resources, Southern Illinois University, Carbondale, IL 62901, USA ORCID ID:E-mail: gxwang@siu.edu (email)
article id 10215, category Research article
Korotimi Ouédraogo, Kangbéni Dimobe, Adjima Thiombiano. (2020). Allometric models for estimating aboveground biomass and carbon stock for Diospyros mespiliformis in West Africa. Silva Fennica vol. 54 no. 1 article id 10215. https://doi.org/10.14214/sf.10215
Highlights: Biomass estimation models developed for Diospyros mespiliformis; Models based on DBH alone predicted aboveground biomass with 97.11% accuracy; Published models had relative error between –72% and +98%; Models for branch and stem biomass were more accurate than those for leaf biomass.

Accurate estimates of aboveground biomass (AGB) strongly depend on the suitability and precision of allometric models. Diospyros mespiliformis Hochst. ex A. DC. is a key component of most sub-Sahara agroforestry systems and, one of the most economically important trees in Africa. Despite its importance, very few scientific information exists regarding its biomass and carbon storage potential. In this study direct method was used to develop site-specific biomass models for D. mespiliformis tree components in Burkina Faso. Allometric models were developed for stem, branch and leaf biomass using data from 39 tree harvested in Sudanian savannas of Burkina Faso. Diameter at breast height (DBH), tree height, crown diameter (CD) and basal diameter (D20) were regressed on biomass component using non-linear models with DBH alone, and DBH in combination with height and/or CD as predictor variables. Carbon content was estimated for each tree component using the ash method. Allometric models differed between the experimental sites, except for branch biomass models. Site-specific models developed in this study exhibited good model fit and performance, with explained variance of 81–98%. Using models developed from other areas would have underestimated or overestimated biomass by between –72% and +98%. Carbon content in aboveground components of D. mespiliformis in Tiogo, Boulon and Tapoa-Boopo was 55.40% ± 1.50, 55.52% ± 1.06 and 55.63% ± 1.00, respectively, and did not vary significantly (P-value = 0.909). Site-specific models developed in this study are useful tool for estimating carbon stocks and can be used to accurately estimate tree components biomass in vegetation growing under similar conditions.

  • Ouédraogo, University Joseph Ki-Zerbo, UFR/SVT, Laboratory of Plant Biology and Ecology, 03 B.P. 7021 Ouagadougou 03, Burkina Faso ORCID ID:E-mail: okorotimi@yahoo.fr (email)
  • Dimobe, University Joseph Ki-Zerbo, UFR/SVT, Laboratory of Plant Biology and Ecology, 03 B.P. 7021 Ouagadougou 03, Burkina Faso; University of Dédougou, Institut des Sciences de l’Environnement et du Développement Rural (ISEDR), BP 139 Dédougou, Burkina Faso; West African Science Service Center on Climate Change and Adapted Land Use, Competence Center, Avenue Muamar Ghadhafi, Ouagadougou, BP 9507, Burkina Faso ORCID ID: https://orcid.org/0000-0001-5536-9700 E-mail: kangbenidimobe@gmail.com
  • Thiombiano, University Joseph Ki-Zerbo, UFR/SVT, Laboratory of Plant Biology and Ecology, 03 B.P. 7021 Ouagadougou 03, Burkina Faso ORCID ID:E-mail: adjima_thiombiano@yahoo.fr
article id 10196, category Research article
Karri Uotila, Jari Miina, Timo Saksa, Ron Store, Kauko Kärkkäinen, Mika Härkönen. (2020). Low cost prediction of time consumption for pre-commercial thinning in Finland. Silva Fennica vol. 54 no. 1 article id 10196. https://doi.org/10.14214/sf.10196
Highlights: Time consumption (TC) in pre-commercial thinning (PCT) can be predicted by variables describing site and stands conditions and previous silvicultural management; Applying variables available in forest resources data the field-assessment of worksite difficulty factors is not needed; The TC model could facilitate the predictions of the labour costs of PCT in forest information systems.

The time consumption (TC) of pre-commercial thinning (PCT) varies greatly among sites, stands and forest workers. The TC in PCT is usually estimated by field-assessed work difficulty factors. In this study, a linear mixed model for the TC in PCT was prepared by utilizing forest resources data (FRD). The modelling data included 11 848 and validation data included 3035 worksites with TC information recorded by forest workers within the period of 2008–2018. The worksites represented a range of site and stand conditions across a broad geographical area in Finland. Site and stand characteristics and previous management logically explained the TC in PCT. The more fertile the site, the more working time was needed in PCT. On sites of medium fertility, TC in the initial PCT increased with stand age by 0.5 h ha–1 yr–1. Site wetness increased the TC. PCT in summer was more time consuming than in spring. Small areas were more time consuming to PCT per hectare than larger ones. The between-forest worker variation involved in the TC was as high as 35% of the variation unexplained by the TC model. The coefficient of determination in validation data was 19.3%, RMSE 4.75 h ha–1 and bias –1.6%. The TC model based on FRD was slightly less precise than the one based on field-assessed work difficulty factors (removal quantity and type and terrain difficulty): RMSE 4.9 h ha–1 vs. 4.1 h ha–1 (52% vs. 43%). The TC model could be connected to forest information systems where it would facilitate the predictions of the labour costs of PCT without field-assessing work difficulty factors.

  • Uotila, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland ORCID ID:E-mail: karri.uotila@luke.fi (email)
  • Miina, Natural Resources Institute Finland (Luke), Natural resources, Yliopistokatu 6 B, FI-80100 Joensuu, Finland ORCID ID:E-mail: jari.miina@luke.fi
  • Saksa, Natural Resources Institute Finland (Luke), Natural resources, Survontie 9, FI-40500 Jyväskylä, Finland ORCID ID:E-mail: timo.saksa@luke.fi
  • Store, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Teknologiakatu 7, FI-67100 Kokkola, Finland ORCID ID:E-mail: ron.store@luke.fi
  • Kärkkäinen, ORCID ID:E-mail: kauko.karkkainen@gmail.com
  • Härkönen, Tornator Oyj, Pielisentie 2–6, FI-81700 Lieksa, Finland ORCID ID:E-mail: mika.harkonen@tornator.fi
article id 10163, category Research article
Uttam Thangjam, Uttam K. Sahoo, Pentile Thong. (2020). Characterization of morphometric, reproductive and seedling traits of Parkia timoriana in northeast India. Silva Fennica vol. 54 no. 1 article id 10163. https://doi.org/10.14214/sf.10163
Highlights: Among provenances, Pherema (P1) Serchip (P10) and Jiribam (P7) were associated with stress tolerant and better quality seedlings.; P1 gave the best result for seed traits including high germinability, P10 showed highest seedling vigour, while P7 corresponds to high-quality pod related traits; Variations in morphological, germinative and seedling growth characters of seeds across provenance further illustrate the importance of site selection for the production of better quality trees.

We studied variations on different traits of Parkia timoriana (D.C.) Merr. in twelve provenances systematically from their source of origin to a controlled environment where representative seedlings were grown. Among the provenances, P1 gave the best result for seed traits including germination traits, P7 for pod traits and P10 for seedling vigour. Effects of seasonal distribution of rainfall and temperature on seed and pod traits were also determined by computing multiple regression analysis. The results displayed winter rainfall and summer temperature as the most important factor determining pod and seed traits. Latitude also significantly (P < 0.001) affected PWT (r = 0.52), SWP (r = 0.46) and SW (r = 0.50). A common garden study for germination and seedling growth indicated P1 and P10 provenance as the best among all. Seeds drawn from P10 gave the highest seedling vigour with an average growth rate of 0.61 cm/day from 90th to 180th day. Highest broad-sense heritability values (h2) were observed in germination traits, followed by seedling collar diameter. The lowest h2 was observed for seedling height.

  • Thangjam, Department of Forestry, School of Earth Sciences & Natural Resource Management, Mizoram University, Aizawl-796004, Mizoram, India ORCID ID: https://orcid.org/0000-0003-1263-5348 E-mail: thangjam1987@gmail.com
  • Sahoo, Department of Forestry, School of Earth Sciences & Natural Resource Management, Mizoram University, Aizawl-796004, Mizoram, India ORCID ID: https://orcid.org/0000-0002-6524-1775 E-mail: uksahoo_2003@rediffmail.com (email)
  • Thong, Department of Forestry, School of Earth Sciences & Natural Resource Management, Mizoram University, Aizawl-796004, Mizoram, India ORCID ID: https://orcid.org/0000-0002-5358-181X E-mail: pentilethong@gmail.com
article id 10084, category Research article
Mihails Čugunovs, Eeva-Stiina Tuittila, Jari Kouki. (2020). Proximity to charred logs in burned forests likely affects decomposition processes in the soil. Silva Fennica vol. 54 no. 1 article id 10084. https://doi.org/10.14214/sf.10084
Highlights: Standardised organic substrate decomposition was tentatively observed to be faster adjacent to non-charred downed logs than away from the logs or adjacent to charred logs; A spatial linkage was observed between non-charred logs and decomposition in the soil in burned boreal forests; Proximity to a charred log may provide a micro-environment where decomposition rates differ from the surrounding forest soil.

We studied the spatial decomposition rates of standardised organic substrates in soils (burned boreal pine-dominated sub-xeric forests in eastern Finland), with respect to charred and non-charred coarse woody debris (CWD). Decomposition rates of rooibos plant litter inside teabags (C:N = 42.870 ± 1.841) and pressed-sheet Nordic hardwood pulp (consisting of mainly alpha-cellulose) were measured at 0.2 m distance from 20 charred (LC0.2) and 40 non-charred logs (LNC0.2). We also measured decomposition at 60 plots located 3–10 m away from downed logs (L3,10). The rooibos decomposition rate constant ‘k’ was 8.4% greater at the LNC0.2 logs than at the L3,10 or LC0.2 logs. Cellulose decomposed more completely in 1 micron mesh bags at LNC0.2 (44% of buried bags had leftover material) than at LC0.2 (76%) or L3,10 (70%). Decomposition of cellulose material was rapid but varied greatly between sampling plots. Our results indicate that decomposition of the standardised organic matter was more rapid close to CWD pieces than further away. However, only the plots located near non-charred logs (LNC0.2) exhibited high decomposition rates, with no corresponding increase observed at the charred logs (LC0.2). This suggests a possible noteworthy indirect effect of forest burning on soil organic matter (SOM) decomposition rates close to charred CWD after forest fires. We urge for more studies on this tentative observation as it may affect the estimates on how fires affect carbon cycling in forests.

  • Čugunovs, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: mihails.cugunovs@gmail.com (email)
  • Tuittila, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID: https://orcid.org/0000-0001-8861-3167 E-mail: eeva-stiina.tuittila@uef.fi
  • Kouki, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID: https://orcid.org/0000-0003-2624-8592 E-mail: jari.kouki@uef.fi
article id 10051, category Research article
Anna-Kaisa Kosenius, Artti Juutinen, Liisa Tyrväinen. (2020). The role of state-owned commercial forests and firm features in nature-based tourism business performance. Silva Fennica vol. 54 no. 1 article id 10051. https://doi.org/10.14214/sf.10051
Highlights: State-owned commercial forests provide an important part of nature-based tourism enterprises’ service scope; Increase in turnover during five years vary depending on provided services; Entrepreneurial attitude associates with willingness to participate in a landscape and recreational value trading scheme; Increasing international demand for nature-based tourism promotes business possibilities, needs attention to forest environments and smooth co-operation between actors.

Nature-based tourism (NBT) is a growing industry within regions rich in natural amenities worldwide. An important feature of NBT business is the dependence on the quality of surrounding environment. This paper addresses the role of the management of commercial forests owned by the state in Finnish Lapland. The paper explores the NBT entrepreneurs’ willingness to participate in a proposed new landscape and recreational value trading (LRVT) and elaborates the effect of entrepreneur and enterprise characteristics, such as entrepreneurial attitude, venture size, and a variety of services offered to customers, on the experienced and expected growth of NBT enterprise. The survey data on NBT enterprises were analyzed with ordered and binary logit models. The willingness of enterprises to participate in LRVT depended on the venture size, entrepreneurial attitude, and type of activities offered to customers. The results show that relatively young and small-sized enterprises have faced difficulties in developing their business. Entrepreneurial experience, risk-taking and intention to develop new business associate positively with expected increase in turnover.

  • Kosenius, University of Helsinki, Department of Economics and Management, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID: https://orcid.org/0000-0002-1528-8145 E-mail: anna-kaisa.kosenius@helsinki.fi (email)
  • Juutinen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Paavo Havaksentie 3, FI-90570 Oulu, Finland ORCID ID: https://orcid.org/0000-0003-4300-5365 E-mail: artti.juutinen@luke.fi
  • Tyrväinen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Latokartanonkaari 9, FI-00790 Helsinki, Finland ORCID ID: https://orcid.org/0000-0001-9941-8228 E-mail: liisa.tyrvainen@luke.fi

Category: Research note

article id 10262, category Research note
Markus Melin, Heli Viiri, Olli-Pekka Tikkanen, Riku Elfving, Seppo Neuvonen. (2020). From a rare inhabitant into a potential pest – status of the nun moth in Finland based on pheromone trapping. Silva Fennica vol. 54 no. 1 article id 10262. https://doi.org/10.14214/sf.10262
Highlights: The nun moth is a significant defoliator of coniferous forests in Central-Europe; In Finland, the populations have grown and expanded northwards; Pheromone trapping confirmed the species’ presence throughout central- and southern Finland; The risk of the nun moth becoming a pest for Finland is real as the area offers endless habitats, and climatic conditions are becoming more favourable; This note describes the results from the first nun moth surveys conducted in 2018 and 2019.

Forests are affected by climate change in various ways. This includes abiotic factors such as droughts, but also biotic damage by pest insects. There are numerous examples from cases where pest insects have benefitted from longer growing seasons or from warmer summers. Similarly, new pest insects have been able to expand their range due to climatic conditions that have changed from hostile to tolerable. Such seems to be the case with the nun moth (Lymantria monacha), an important defoliator of coniferous trees in Europe. For centuries, the species has had massive outbreaks across Central-Europe, while it has been a rare inhabitant in Northern Europe. Recently, the nun moth population in Finland has not only expanded in range, but also grown more abundant. This research note describes the results from the first years (2018–2019) of a monitoring program that is being conducted with pheromone traps across central and southern Finland. So far, the northernmost individuals were trapped near the 64 N degrees. However, there were more southern locations where no moths were trapped. The species was present in every trapping site below the latitude of 62 N degrees. More importantly, at some sites the abundance of the nun moth suggested that local forest damage may already occur. Given the current climatic scenarios for Fennoscandia, it is likely that the nun moth populations will continue to grow, which is why systematic surveys on their abundance and range expansions will be topical.

  • Melin, Natural Resources Institute Finland, Yliopistokatu 6b, FI-80100 Joensuu, Finland ORCID ID: https://orcid.org/0000-0001-7290-9203 E-mail: markus.melin@luke.fi (email)
  • Viiri, Natural Resources Institute Finland, Yliopistokatu 6b, FI-80100 Joensuu, Finland; UPM-Kymmene Oyj, UPM Forest, Åkerlundinkatu 11 B, FI-33100 Tampere, Finland ORCID ID:E-mail: heli.viiri@upm.com
  • Tikkanen, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID ID:E-mail: olli-pekka.tikkanen@uef.fi
  • Elfving, Natural Resources Institute Finland, Yliopistokatu 6b, FI-80100 Joensuu, Finland; University of Oulu, Department of Biology, Pentti Kaiteran katu 1, FI-90014 Oulu, Finland ORCID ID:E-mail: riku.elfving@gmail.com
  • Neuvonen, University of Turku, Biodiversity Unit, Kevo Subarctic Research Institute, FI-20014 Turku, Finland ORCID ID:E-mail: seppo.neuvonen@utu.fi

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