Articles containing the keyword 'mechanical site preparation'

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

Over 20% of regeneration operations will be on drained peatland in the next decade in Finland. There are only a few studies comparing the planting success and the risk of pine weevil (Hylobius abetis (L.) feeding damage on mineral soil and drained peatland. Thirty sites planted with Norway spruce (Picea abies (L.) H. Karst.) container seedlings in 2009 in Southern and Central Finland were inventoried three growing seasons after planting. Prediction models for the probability of survival, pine weevil damage and the presence of ground vegetation cover were done separately for peatland and mineral soil sites. The planting success was 17% lower on peatland sites (1379 surviving seedlings ha^–1) than on mineral soil (1654 seedlings ha^–1). The factors explaining the survival were the ground vegetation cover and type of the planting spot on the peatland, and the ground vegetation cover on mineral soil. On mineral soil, 76% of the planting spots were on cultivated mineral soil while on peatland only 28% of the seedlings were planted on similar spots. There were also fewer seedlings that were surrounded by dense ground vegetation on mineral soil (4%) than on peatland (14%). Pine weevil feeding damage did not differ significantly on peatland (23%) or mineral soil (18%). The more time there was from clear-cutting, the more the probability of pine weevil feeding damage was reduced on both soil classes. Additionally, cover vegetation in the vicinity of the seedlings increased on mineral soil. Cultivated planting spots, especially those covered by mineral soil, prevented pine weevil feeding and reduced the harmful effects of vegetation on the seedlings both on mineral soil and peatland.

• Luoranen, Natural Recourses Institute Finland (Luke), Production systems, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Viiri, UPM Forest, Peltokatu 26 C, P.O. Box 85, FI-33100 Tampere, Finland https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com

• Granhus, Norwegian University of Life Sciences, Dept. of Ecology and Natural Resource Management (INA), P.O.Box 5003, NO-1432 Ås, Norway E-mail: aksel.granhus@umb.no
• Fjeld, Swedish University of Agricultural Sciences, Dept. of Forest Resource Management, SE-901 83 Umeå, Sweden E-mail: df@nn.se

Today, conflicts often occur in northern Fennoscandia (also known as Sápmi) between forestry and reindeer husbandry. Continuous cover forestry (CCF) is requested by both reindeer herding communities and the general public and is becoming more common, but the forest industry criticizes CCF for lower wood production. Mechanical site preparation (MSP) increases regeneration success and, thus, increases wood production in CCF. To reduce the conflict between forestry and reindeer husbandry, MSP in Sápmi should destroy as little ground lichen as possible. Today, there are no solutions for gentle and lichen-adapted MSP in CCF. Thus, there is a strong need to develop and test new technical solutions that increase regeneration success in a lichen-adapted way during CCF in Sápmi. We suggest that MSP solutions be developed which are gentle, work selectively and function in shelterwoods, gap cuts, and selection cutting stands. We envision that these solutions could fill the gap between the desired adaptivity on the part of the reindeer herding communities and the desired efficiency on the part of the forest industry. Such MSP technology would contribute to increased acceptance of CCF in the forest industry, higher biodiversity, and considerably reduce the conflict between forestry and reindeer herding communities.

• Ersson, Swedish University of Agricultural Sciences (SLU), School of Forest Management, SE-739 21 Skinnskatteberg, Sweden https://orcid.org/0000-0003-2442-7482 E-mail: back.tomas.ersson@slu.se
• Hansson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-9788-1734 E-mail: linnea.hansson@skogforsk.se
• Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se
• Sandström, Swedish University of Agricultural Sciences (SLU), Department of Forest Resource Management, SE-901 83 Umeå, Sweden https://orcid.org/0000-0003-0977-0071 E-mail: per.sandstrom@slu.se
• Sonesson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-2018-7496 E-mail: johan.sonesson@skogforsk.se