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Monitoring of forest biodiversity and habitats is an important part of forest conservation, but due to the impossible task of monitoring all species, indicator species are frequently used. However, reliance on an incorrect indicator of valuable habitat can reduce the efficiency of conservation efforts. Birds are often used as indicators as they are charismatic, relatively easy to survey, and because we often have knowledge of their habitat and resource requirements. In the Swedish government's environmental quality goals, there are a number of bird species identified as being associated with 'older' and 'high natural value' forests. Here we evaluate the occurrence of four of these indicator species using data from 91 production forest stands and 10 forest reserves in southern Sweden. The bird species assessed are willow tit Poecile montanus, coal tit Periparus ater, European crested tit Lophophanes cristatus and Eurasian treecreeper Certhia familiaris. For the production stands assessed, these indicator species exhibited no significant preferences regarding forest composition and structure, indicating a wider range of habitat associations than expected. These species frequently showed territorial behavior in forest stands <60 and even 40 years of age; much younger than the 120‐year threshold for 'older forest' as defined by governmental environmental goals. As almost 80% of the production stands ≥10 years old included at least one of the four indicator species, this raises questions regarding the suitability of these species as indictors of forests of high conservational value in southern Sweden. Notably, besides the four species assessed here, none of the additional indicator taxa identified by the government, were recorded in the 10 reserves. This outcome may reflect the difficulties involved in finding bird indicator species indicative of high natural values in this region. Our results highlight the importance of coupling bird surveys with quantified assessments of proximate vegetation cover. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change is altering the management of production forests. These changes are motivated by the need to adapt to the uncertainties and risks of climate change, and by the need to enlist their carbon storage and sequestration capacity as part of global mitigation efforts. These changes do however raise concerns regarding the potential implications for forest biodiversity. Here we evaluate these concerns by assessing the biodiversity implications of climate change adaptation and mitigation strategies (CCAMS) being implemented in the production forests of Sweden. We do so by identifying biodiversity goals aimed specifically at closing the existing gap between the habitat requirements of forest-dependent species, and the conditions provided by production forests, in terms of tree species composition, forest structures, and spatio-temporal forest patterns. We then use the existing literature to determine whether and by which pathway each CCAMS is likely to bridge or extend this gap. Our results indicate that CCAMS will often come into direct or partial conflict with Swedish biodiversity goals in production forests. Furthermore, some CCAMS which are inconsistent with biodiversity goals, such as logging residue removal, are being implemented more extensively than those which were most consistent with biodiversity goals. We nevertheless challenge the necessity of setting the preservation of forest biodiversity against climate change mitigation and adaptation. We clarify how CCAMS with negative biodiversity implications may still be implemented without adverse outcomes, if coupled with conservation interventions, or combined with other CCAMS deemed complementary in habitat provision. [ABSTRACT FROM AUTHOR]

The rotation lengths of intensively managed production forests may be altered to achieve a variety of goals, with correspondingly implications for biodiversity. Here we consider the potential implications of shortened rotation times for biodiversity in planted monocultures of the two most common production tree species in Sweden, Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). To do so we surveyed bird, bryophyte, epiphytic lichen and vascular plant diversity in 80 and 55-year-old stands; stand ages which approximate present-day and potential future rotation lengths in this region respectively. We found clear differences in the species communities of the 55 compared to the 80-year-old stands for both understory species and epiphytes, but not for birds. Nevertheless, bird species richness was still highest in the 80-year-old Norway spruce dominated stands. Dead wood amount was also highest the 80-year-old Norway spruce stands. Highest species richness of epiphytic lichens was found in 80-year-old Scots pine stands. However, 55-year-old Scots pine stands had a higher understory species richness and diversity than the older Scots pine stands, including a larger number of open land species. The 80-year-old forest stands examined may be considered old with respect to production forest rotation lengths in Sweden but are relatively young when comparing stand ages of unmanaged natural forest stands. Nevertheless, our results indicate that shortening the rotation time of Scots pine and Norway spruce, in this part of Sweden from 80 to 55 years, could have important consequences for forest biodiversity. These consequences are primarily inferred from the likely implications from shortened rotations for lichens community composition and diversity in both Norway spruce and Scots pine stands, as well as impacts on understory plant species in Norway spruce stands., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Petersson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The choice of tree species used in production forests matters for biodiversity and ecosystem services. In Sweden, damage to young production forests by large browsing herbivores is helping to drive a development where sites traditionally regenerated with Scots pine (Pinus sylvestris) are instead being regenerated with Norway spruce (Picea abies). We provide a condensed synthesis of the available evidence regarding the likely resultant implications for forest biodiversity and ecosystem services from this change in tree species. Apart from some benefits (e.g. reduced stand-level browsing damage), we identified a range of negative outcomes for biodiversity, production, esthetic and recreational values, as well as increased stand vulnerability to storm, frost, and drought damage, and potentially higher risks of pest and pathogen outbreak. Our results are directly relevant to forest owners and policy-makers seeking information regarding the uncertainties, risks, and trade-offs likely to result from changing the tree species in production forests.

The multi-scale approach to conserving forest biodiversity has been used in Sweden since the 1980s, a period defined by increased reserve area and conservation actions within production forests. However, two thousand forest-associated species remain on Sweden's red-list, and Sweden's 2020 goals for sustainable forests are not being met. We argue that ongoing changes in the production forest matrix require more consideration, and that multi-scale conservation must be adapted to, and integrated with, production forest development. To make this case, we summarize trends in habitat provision by Sweden's protected and production forests, and the variety of ways silviculture can affect biodiversity. We discuss how different forestry trajectories affect the type and extent of conservation approaches needed to secure biodiversity, and suggest leverage points for aiding the adoption of diversified silviculture. Sweden's long-term experience with multi-scale conservation and intensive forestry provides insights for other countries trying to conserve species within production landscapes.

Boreal forests form the largest and least disturbed forest biome in the northern hemisphere. However, anthropogenic pressure from intensified forest management, eutrophication, and climate change may alter the ecosystem functions of understory vegetation and services boreal forests provide. Swedish forests span long gradients of climate, nitrogen deposition, and management intensity. This makes them ideal to study how the species composition and functions of other, more pristine, boreal forests might change under increased anthropogenic pressure. Moreover, the National Forest Inventory (NFI) has collected systematic data on Swedish forest vegetation since the mid-20th century. We use this data to quantify changes in vegetation types between two periods, 1953-1962 and 2003-2012. The results show changes in forest understory vegetation since the 1950s at scales not previously documented in the boreal biome. The spatial extent of most vegetation types changed significantly. Shade-adapted and nutrient-demanding species (those with high specific leaf area) have become more common at the expense of light-demanding and nutrient-conservative (low specific leaf area) species. The cover of ericaceous dwarf shrubs decreased dramatically. These effects were strongest where anthropogenic impacts were greatest, suggesting links to drivers such as nitrogen deposition and land-use change. These changes may impact ecosystem functions and services via effects on higher trophic levels and faster plant litter decomposition in the expanding vegetation types. This, in turn, may influence nutrient dynamics, and consequently ecosystem productivity and carbon sequestration., (© 2019 by the Ecological Society of America.)