The utilization rate of woody biomass in eastern Finland is high and expected to increase further in the near future as set out in several regional, national and European policies and strategies. The aim of this study was to assess the sustainability impacts of changes in fuel consumption patterns. We investigated fossil and woody biomass-based energy production chains in the region of North Karelia, focusing on some economic, environmental and social indicators. Indicators were selected based on stakeholder preferences and evaluated using the Tool for Sustainability Impact Assessment (ToSIA). The analysis was based on representative values from National Forest Inventory data, scientific publications, national and regional statistics, databases, published policy targets and expert opinion. From the results it became evident that shifting from fossil to wood-based energy production implies some trade-offs. Replacing oil with woody biomass in energy production would increase the local value added remaining in the region, create employment opportunities and would reduce total GHG emissions. However, firewood, wood chips from small-diameter trees from early thinning and wood pellets have high production costs. Moreover, large greenhouse gas emission resulted from wood pellet production. The case study generated valuable reference data for future sustainability assessments and demonstrated the usefulness of ToSIA as a tool presenting existing knowledge on sustainability impacts of alternative energy supply chains to inform decision making.

Grazing by large mammals can affect small-mammal populations by modifying the ground-layer vegetation, which provides them with food and shelter. The aim of this study was to investigate the impact of semi-domesticated reindeer grazing on smallmammal abundance in boreal forests/subarctic tundra ecosystems in a large-scale exclosure experiment in northernmost Finnish Lapland. In our experiment spanning four years, reindeer grazing affected the abundance of arvicoline voles, which were less abundant in grazed areas. This was probably due to a reduction in the abundance and height of bilberry, an important forage plant for both voles and reindeer. Changes in ground-layer vegetation affected the general condition of bank voles, which had significantly lower body mass in grazed areas. The abundance of insectivorous shrews was also reduced by grazing, probably due to a reduction in ground-dwelling invertebrates as an indirect effect of changes in the composition of ground-layer vegetation. A grazing-induced red...

Silvicultural practices, effective fire suppression, and increased browser densities have profoundly altered structural diversity in boreal forests. Prescribed burning and retention forestry may counteract losses in structural diversity in managed forests by maintaining a higher deciduous admixture. We constructed an experiment on 18 sites with three types of timber harvesting (uncut, cut with retention, and clearcut) and burned half of these sites. Subsequently, we established a herbivore treatment with three compartments (unfenced, fenced excluding moose (Alces alces (Linnaeus, 1758)), and fenced excluding moose and hares (Lepus spp.)). In these compartments, we planted rowan (Sorbus aucuparia L.), European aspen (Populus tremula L.), and silver birch (Betula pendula Roth) seedlings and monitored these for 17 years. Birch and rowan mortality were lower on cut and burned sites, with retention further enhancing birch survival on these sites. Retention without burning did not lower seedling mortality of any tree species. While browsing resulted in greater mortality on cut sites, burning appeared to greatly reduce browsing on birch and rowan. On mature uncut sites, seedlings of all tree species exhibited high mortality. Our findings show that deciduous tree recruitment can be improved through prescribed burning, particularly for birch and rowan, and that browsing impacts on deciduous trees depend on forest age.