Articles by Line Djupström

Managing boreal forests while maintaining biodiversity is challenging due to climate change and increasing resource demands. Retention forestry, in which some trees are deliberately left during harvesting, mitigates the negative impacts of clearcutting, but it remains unclear whether regeneration can be ensured as tree retention levels increase. This study assessed Scots pine (Pinus sylvestris L.) regeneration over 4.5 years in the southern boreal zone of Sweden (Effaråsen) under five treatments: four tree retention levels (3%, 10%, 30%, 50%) and a 50% retention treatment with prescribed burning. Mechanical site preparation (MSP) and regeneration methods were key drivers of success in Scots pine forest regeneration. MSP consistently and positively influenced all regeneration variables (height, growth, survival, germination, and recruitment) across planting, seeding, and natural regeneration. Direct seeding produced the highest number of seedlings per hectare, while planting yielded the tallest seedlings with high survival. Natural regeneration produced fewer and smaller seedlings and was insufficient to ensure stand establishment. Stand-scale retention levels generally did not affect regeneration, but retained trees within 20 meters negatively affected the height, growth, and survival of planted and seed-germinated seedlings, likely due to competition, indicating a proximity effect. Burned areas showed greater height and survival, suggesting that prescribed burning enhances regeneration by reducing competition while potentially creating habitat relevant for conservation and specialized species. Overall, the results highlight that retention trees intended for biodiversity have a limited role as seed trees for regeneration, and careful planning is needed to use them for biodiversity purposes without negatively impacting regeneration.

• Lariviere, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden; Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden https://orcid.org/0000-0002-1415-3476 E-mail: delphine.lariviere@slu.se
• Djupström, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden; Swedish University of Agricultural Sciences (SLU), Department of Wildlife, Fish and Environmental Studies, Umeå SE-901 83, Sweden https://orcid.org/0000-0003-4536-7765 E-mail: line.djupstrom@skogforsk.se
• Nilsson, The Forestry Research Institute of Sweden (Skogforsk), Ekebo 2250, SE-268 90 Svalöv, Sweden https://orcid.org/0000-0002-5632-6523 E-mail: oscar.nilsson@skogforsk.se

Since the 1950s, more than 200 000 km of roads have been built in Sweden’s forests, making them easily accessible and open to multiple uses. The aim of this study was to review the impacts of forest roads in Sweden from a broad perspective encompassing social, ecological, and environmental factors. The Swedish case is interesting because it has an extensive network of permanent forest roads which were built primarily for forestry-related transportation but are currently used by many other stakeholders for many different purposes. Forest roads not only facilitate transportation of wood, machinery, personnel, and equipment into and out of the forest but also enable emergency response to wildfires and support berry and mushroom picking, hunting, recreation, tourism, and access to second homes. The roads increase the opportunities for members of the public to experience forests in various ways. Conflicts arise when different interests collide, for example when the interests of the forest owner clash with those of commercial berry-picking companies, tourism entrepreneurs, or reindeer (Rangifer tarandus L.) herding. Forest roads may have ecological impacts such as barrier and disturbance effects, fragmentation or loss of habitats, altering fauna movement patterns, and changing the composition of plant and insect species. The environmental impacts of forest roads relate to, among other things, hydrology, water quality, and erosion. Predicted changes in the climate are likely to place new demands on Swedish forest roads but, despite their extent, this review shows that there is only a small amount of rather fragmented research on their social, ecological, and environmental consequences. Overall, few studies appear to cover both social and ecological/environmental factors and their interactions, either in Sweden or elsewhere. This review provides examples of such interactions in the case of Sweden, and suggests that more research into these and the specific social, ecological, and environmental factors involved is warranted.

• Ring, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0002-8962-9811 E-mail: eva.ring@skogforsk.se
• Wallgren, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden; Swedish University of Agricultural Sciences, Department of Wildlife, Fish, and Environmental Studies, 907 36 Umeå, Sweden https://orcid.org/0000-0002-3172-4496 E-mail: martha.wallgren@skogforsk.se
• Mårald, Umeå University, Department of Historical. Philosophical and Religious Studies, 901 87 Umeå, Sweden https://orcid.org/0000-0002-2291-9910 E-mail: erland.marald@umu.se
• Westerfelt, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0003-2040-8305 E-mail: per.westerfelt@skogforsk.se
• Djupström, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden; Swedish University of Agricultural Sciences, Department of Wildlife, Fish, and Environmental Studies, 907 36 Umeå, Sweden https://orcid.org/0000-0003-4536-7765 E-mail: line.djupstrom@skogforsk.se
• Davidsson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0009-0007-2736-8656 E-mail: Aron.davidsson@skogforsk.se
• Sonesson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0002-2018-7496 E-mail: Johan.sonesson@skogforsk.se