Silva Fennica vol. 58 no. 5 | 2024

• Maltamo, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-9904-3371 E-mail: matti.maltamo@uef.fi

• Korhonen, Natural Resources Institute Finland (Luke), P.O. Box 68, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-6198-853X E-mail: kari.t.korhonen@luke.fi

The poor cost-effectiveness of mechanized planting (MECP) is the main reason for the low mechanization rate of planting. In this study, we investigated the productivity of the mechanized excavator-based planting of Norway spruce (Picea abies [L.] H. Karst.) seedlings based on data collected by the Risutec Asta documentation system. We also compared the costs of a MECP chain with two different manual planting (MAP) chains, where mounding was carried out by a crawler excavator (EXC) or a continuously advancing mounder (CONT). The MECP of seedlings was carried out using an EXC equipped with a Risutec PM-160 planting device. Generally, the nine study sites in western Finland contained few surface obstacles (e.g., the logging residues had mainly been harvested), which made the conditions very suitable for MECP. The average production time taken by the MECP was 9 h ha^-1. The operating hour (G₁₅-h) productivity averaged 215 seedlings G₁₅-h^-1 , with the mean planting time being 13.8 s seedling^-1. Loading 160 seedlings into the seedling cassette took approximately 10 min (3.8 s seedling^-1). Overall, the cost of the MECP was about 5% lower than for the EXC + MAP. However, when productivity was set at <200 seedlings G₁₅-h^-1 , the cost of the MECP was higher than that of the EXC + MAP. Based on our findings, the most cost-efficient planting chain was CONT + MAP. However, based on our results, the required level of productivity can be achieved if the sites are suitable for MECP and the machine operators are skilled.

• Kemppainen, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland; Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0009-0000-6184-8812 E-mail: kalle.kemppainen@uef.fi
• Kärhä, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-8455-2974 E-mail: kalle.karha@uef.fi
• Laitila, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-4431-3319 E-mail: juha.laitila@luke.fi
• Sairanen, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0009-0008-8632-3797 E-mail: anttsair@student.uef.fi
• Kankaanhuhta, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0001-5785-5972 E-mail: ville.kankaanhuhta@luke.fi
• Viiri, UPM-Kymmene Plc, UPM Forest, Peltokatu 26 C 4, FI-33100 Tampere, Finland https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com
• Peltola, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0000-0003-1384-9153 E-mail: heli.peltola@uef.fi

In 2019–2023 the 13th Finnish National Forest Inventory (NFI) was implemented by measuring a total of 62 266 sample plots across the country. The methodology of the sampling and measurements was similar as in the previous inventory, but the proportion and number of remeasured permanent plots was increased to improve the monitoring of annual increment and other changes in the forests. Only 6.2 M ha (14%) of Finland’s total land area (30.4 M ha) is other land than forestry land. Productive and poorly productive forests cover 22.9 M ha (75%) of the total land area.  The forest area has remained stable in recent decades but the forest area available for wood supply (FAWS) has decreased due to increased forest protection – 23% of the forestry land and 10% of the productive forest are not available for wood supply. Compared to the previous inventory, forest resources have continued to increase but the average annual increment has declined from 107.8 M m³ to 103.0 M m³. The quality of forests from the timber production point of view has remained relatively good or improved slightly. The area of observed forest damage on FAWS is 8.4 M ha (46% of FAWS area), half of these minor damages with no impact on stand quality. Although the area of forest damage has not increased, the amount of mortality has continued to increase, and is now 8.8 M m³ year^–1. The amount of dead wood has continued to increase in South Finland, while in North Finland the declining trend has turned into a slight increase. Since the 1920s, the area of forestry land has remained stable, but the area of productive forest has increased due to the drainage of poorly productive or treeless peatlands. The total volume of growing stock has increased by 84% and annual increment has more than doubled.

• Korhonen, Natural Resources Institute Finland (Luke), P.O.Box 68, FI-80100 Joensuu, Finland https://orcid.org/0000-0002-6198-853X E-mail: kari.t.korhonen@luke.fi
• Räty, Natural Resources Institute Finland (Luke), P.O.Box 2, FI-00790, Helsinki, Finland https://orcid.org/0000-0001-9898-8712 E-mail: minna.raty@luke.fi
• Haakana, Natural Resources Institute Finland (Luke), P.O.Box 2, FI-00790, Helsinki, Finland E-mail: helena.haakana@luke.fi
• Heikkinen, Natural Resources Institute Finland (Luke), P.O.Box 2, FI-00790, Helsinki, Finland https://orcid.org/0000-0003-3527-774X E-mail: juha.heikkinen@luke.fi
• Hotanen, Natural Resources Institute Finland (Luke), P.O.Box 68, FI-80100 Joensuu, Finland E-mail: juha-pekka.hotanen@luke.fi
• Kuronen, Natural Resources Institute Finland (Luke), P.O.Box 2, FI-00790, Helsinki, Finland https://orcid.org/0000-0002-8089-7895 E-mail: mikko.kuronen@luke.fi
• Pitkänen, Natural Resources Institute Finland (Luke), P.O.Box 68, FI-80100 Joensuu, Finland https://orcid.org/0000-0002-7583-6297 E-mail: juho.pitkanen@luke.fi

• Zhang, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80101 Joensuu, Finland https://orcid.org/0000-0001-7876-9635 E-mail: shaohui.zhang@uef.fi
• Korhonen, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-9352-0114 E-mail: lauri.korhonen@uef.fi
• Nummenmaa, Tampere University, Kalevantie 4, FI-33100 Tampere, Finland https://orcid.org/0000-0002-9896-0338 E-mail: timo.nummenmaa@tuni.fi
• Bianchi, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0001-9544-7400 E-mail: simone.bianchi@luke.fi
• Maltamo, School of Forest Sciences, University of Eastern Finland, Yliopistokatu 7, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-9904-3371 E-mail: matti.maltamo@uef.fi

Plant growth-promoting rhizobacteria (PGPR) and filtered sludge are widely used to improve soil fertility and plant yields. In this study, we evaluated the impact of sludge and/or PGPR application on the nutrient contents and enzyme activities of the soil as well as on plant growth. We planted bare-root eucalyptus seedlings in (1) soil amended with filtered sludge from Nanning sugar factory (FS), (2) soil amended with filtered sludge + PGPR (BF), and (3) non-amended soil (control). Soil fertility and eucalyptus growth were determined after 3, 6, 9, and 12 months. Results demonstrated that FS treatment significantly increased eucalyptus growth compared to the control, particularly after six months. Bacterial fertilizer (BF) also increased soil urease and sucrase activities, although differences diminished over the study period. Our findings suggest that the integration of bacterial fertilizers and filtered sludge can serve as an effective and environmentally friendly strategy to improve soil health and promote sustainable eucalyptus cultivation. This research contributes to the growing body of evidence supporting the use of bio-fertilizers in forestry practices, highlighting their potential to reduce or replace the use of chemical fertilizers while increasing plant productivity.

• Ren, College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, 325035 China; Forestry College, Guangxi University, Daxue E Rd, Xixiangtang District, Nanning, Guangxi, 530004 China https://orcid.org/0000-0002-0156-0726 E-mail: renhan1225@163.com
• Chen, College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, 325035 China E-mail: 21211270104@stu.wzu.edu.cn
• Qin, Forestry College, Guangxi University, Daxue E Rd, Xixiangtang District, Nanning, Guangxi, 530004 China E-mail: qinxiaohong186@163.com
• Zhang, College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, 325035 China E-mail: 00811091@wzu.edu.cn
• Lv, Forestry College, Guangxi University, Daxue E Rd, Xixiangtang District, Nanning, Guangxi, 530004 China E-mail: lvchengqun8@163.com
• Zhou, College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, 325035 China E-mail: rosechl@wzu.edu.cn
• Chen, College of Life and Environmental Sciences, Wenzhou University, Wenzhou, Zhejiang, 325035 China https://orcid.org/0000-0002-3043-6919 E-mail: hualin2100@wzu.edu.cn

We developed tree level biomass (dry weight) models for Norway spruce (Picea abies [L.] H. Karst.), silver birch (Betula pendula Roth), rowan (Sorbus aucuparia L.) and aspen (Populus tremula L.) growing in young spruce dominated seedling stands with high mixture of broadleaves. The study material was collected from three planted Norway spruce seedling stands located on mineral soil in southern Finland. Biomass models were estimated by individual tree component (stem, living branches, foliage, stump, and roots with diameter of 2 mm) by using a multi-response approach (seemingly unrelated regression), which estimated the parameters of the sub-models (tree component) simultaneously. Even though the application and generalization of the developed models can be restricted by the limited material, they provide new information of seedling biomass allocation and more reliable biomass predictions for spruce and birch growing in young seedling stand compared with those of the commonly applied biomass models (Repola 2008, 2009) in Finland. Repola’s models (2008, 2009) tended to produce biased predictions for crown and below-ground biomasses of seedlings by allocating too much biomass to roots and too little to needle and branches. In addition, this study provides biomass models for aspen and rowan, which were not previously available.

• Repola, Natural Resources Institute Finland (Luke), Ounasjoentie 6, FI-96200 Rovaniemi, Finland https://orcid.org/0000-0001-7086-0549 E-mail: jaakko.repola@luke.fi
• Luoranen, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Huuskonen, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0001-8630-3982 E-mail: saija.huuskonen@luke.fi
• Peltoniemi, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0003-2028-6969 E-mail: mikko.peltoniemi@luke.fi
• Väänänen, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: paivi.vaananen@luke.fi
• Uotila, Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@luke.fi

One of the central goals of circular bioeconomy in the Finnish forest-based sector is upgrading the use of wood-based materials, especially wood-based side streams, to higher value-added products. However, despite these ambitions, most wood-based side streams are used in energy production. Within the forest-based sector, innovative solutions for higher value-added production of wood-based side streams are being developed within small and medium-sized companies (SMEs). Therefore, to promote the process of upscaling these solutions, understanding the success of these companies is pivotal. For this end, we conducted a qualitative study with 10 forest-based SMEs utilizing wood-based side streams to understand both the internal and external factors affecting their ability to scale up their business models. By applying the dynamic capabilities approach from management research and the strategic niche management approach from sociotechnical transition studies, we found that even though the companies are internally well positioned to succeed in their growth aspirations, they face barriers from the dominant forest-based regime. The studied SMEs are facing a mismatch between their own business models and the rules and operating principles of the forest-based sector based on linear economy. Overcoming these barriers and challenging the dominant structures within the Finnish forest-based regime would require joint efforts from the companies. However, the companies have a strong technological orientation, which makes them hesitant with regard to horizontal networking. They also operate in diverse markets, making it difficult for them to find common ground. As a result, the pressure for systemic transformation within the forest-based sector remains nominal.

• Kuhmonen, University of Jyväskylä, School of Business and Economics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland https://orcid.org/0000-0002-1407-8349 E-mail: irene.a.kuhmonen@jyu.fi
• Näyhä, University of Jyväskylä, School of Business and Economics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: annukka.nayha@jyu.fi
• Solaranta, University of Jyväskylä, School of Business and Economics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: miisa.solaranta@gmail.com
• Keränen, VTT Technical Research Centre of Finland Ltd, P.O. Box 1603, FI-40101 Jyväskylä, Finland https://orcid.org/0000-0002-5626-2929 E-mail: janne.keranen@vtt.fi

• Wallius, European Forest Institute, Yliopistokatu 6 B, FI-80100, Joensuu, Finland; Jyväskylä University School of Business and Economics, P.O. Box 35, FI-40014 University of Jyväskylä, Finland https://orcid.org/0000-0003-2576-9994 E-mail: venla.j.wallius@jyu.fi
• Kunttu, University of Helsinki, Department of Forest Sciences, P.O. Box 4, FI-00014 University of Helsinki, Finland https://orcid.org/0000-0002-7298-3363 E-mail: janni.kunttu@helsinki.fi
• Hurmekoski, University of Helsinki, Department of Forest Sciences, P.O. Box 4, FI-00014 University of Helsinki, Finland https://orcid.org/0000-0001-8717-7287 E-mail: elias.hurmekoski@helsinki.fi
• Hujala, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-7905-7602 E-mail: teppo.hujala@uef.fi
• Nyrud, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway E-mail: anders.qvale.nyrud@nmbu.no
• Hoen, Norwegian University of Life Sciences, Faculty of Environmental Sciences and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway E-mail: hans.hoen@nmbu.no

We draw insights regarding intricacies with spatially explicit data and analyses when studying the vulnerability of forest socio-ecological systems to disruptive abiotic and biotic factors. Common issues associated with data include location precision, spatial delimitation, methodological comparability, and measurement consistency. Spatial data analyses are challenged by issues of interpolation and extrapolation, inferences using data at different spatial scales, and assessment of disruption impacts at detectable spatial scales. The inextricable empirical nature of spatial data and analyses requires carefully conducting and disclosing the sensitivity of findings, and including robustness tests to openly inform decision-makers on issues of uncertainty associated with possible interventions. These considerations might be central to identifying forest socio-ecological hotspots as forest-dominated geographic areas encompassing social and ecological systems vulnerable to disruptions caused by abiotic and biotic factors, but where risks to human wellbeing may be considerably reduced through adaptive interventions.

• Aguilar, Swedish University of Agricultural Sciences (SLU), Department of Forest Economics, SE-901 83 Umeå, Sweden https://orcid.org/0000-0003-0226-4467 E-mail: francisco.aguilar@slu.se
• Lautrup, University of Copenhagen, Department of Food and Resource Economics, Rolighedsvej 23, 1958 Frederiksberg C, Denmark E-mail: ml@ifro.ku.dk
• Kim, Swedish University of Agricultural Sciences (SLU), Department of Forest Economics, SE-901 83 Umeå, Sweden https://orcid.org/0000-0002-1919-3346 E-mail: dohun.kim@slu.se
• Tangen, Inland Norway University of Applied Sciences, Department of Forestry and Wildlife Management, P.O. Box 2400, Koppang, Norway https://orcid.org/0009-0001-3145-8159 E-mail: ane.tange@inn.no
• Rautiainen, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: aapo.rautiainen@luke.fi
• Brownell, University of Copenhagen, Department of Geosciences and Natural Resource Management, Forest and Bioresources, Rolighedsvej 23, 1958 Frederiksberg C, Denmark https://orcid.org/0000-0002-3798-8783 E-mail: hb@ign.ku.dk
• López, Inland Norway University of Applied Sciences, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, P.O. Box 2400, Koppang, Norway https://orcid.org/0009-0006-6860-3408 E-mail: lucas.lopez@inn.no
• Stratton, University of Copenhagen, Department of Food and Resource Economics, Rolighedsvej 23, 1958 Frederiksberg C, Denmark https://orcid.org/0000-0002-6566-2043 E-mail: adhs@ifro.ku.dk
• Glasenapp, Johann Heinrich von Thünen Institute, Institute of Forestry, Leuschnerstraße 91, 21031 Hamburg-Bergedorf, Germany E-mail: sebastian.glasenapp@thuenen.de
• Korth, Universidad Nacional de Misiones Facultad de Ciencias Forestales, Bertoni 124, Eldorado 3380, Argentina https://orcid.org/0009-0007-3261-8234 E-mail: silviakorth@hotmail.com
• Sjølie, Inland Norway University of Applied Sciences, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, P.O. Box 2400, Koppang, Norway https://orcid.org/0000-0001-8099-3521 E-mail: hanne.sjolie@inn.no
• Bredahl Jacobsen, University of Copenhagen, Department of Food and Resource Economics, Rolighedsvej 23, 1958 Frederiksberg C, Denmark https://orcid.org/0000-0002-1313-6228 E-mail: jbj@ifro.ku.dk