Mid Sweden University

Harvesting naturally dynamic forests causes losses of habitat quality and functional connectivity. Focusing on Sweden as a case study of high-yield rotation forestry, we provide analyses supporting spatial prioritisation of protection, management and restoration of representative functional forest habitat networks. Habitat suitability index modelling of focal bird species was used to analyse how forest naturalness, habitat patch size and functional connectivity affect representative forest habitat networks in Sweden's five ecoregions. Habitat modelling for the least demanding bird species showed that of the mountain ecoregion 57-77% was functional, but in the other three boreal ecoregions only 8-9% were functional. For nemoral forests, the proportions of functional habitat networks were < 3%. More demanding species have even less functional habitat. We highlight the importance of the mountain ecoregion for forest biodiversity conservation, and the urgent need for landscape planning of protection, conservation management and nature restoration in Sweden.

Environmental monitoring is of particular importance for studying biodiversity and ecosystems. Many environmental monitoring programs emphasize plant registrations as part of their inventory responsibilities. Among the various methods available for surveying plant communities, we focus on presence/absence (P/A) sampling due to its underutilized potential. P/A sampling offers several advantages over other methods, particularly its efficiency in terms of time and cost. However, interpreting direct information from this type of data can be challenging, as the results are heavily dependent on plot size and species distribution patterns. To overcome these difficulties, model-based assumptions are necessary. In this article, we propose a method for estimating parameters of an inhomogeneous Neyman-Scott point process, specifically a Matérn cluster process, using P/A data. The inhomogeneity is modeled by allowing the offspring process intensity to vary with environmental covariates. The proposed estimators and their corresponding confidence intervals are evaluated through Monte Carlo simulations and empirical data (P/A registrations for three plant species) collected by surveyors in Northern Sweden. The results indicate that the method generally produces nearly unbiased estimators, particularly when the sample size is sufficiently large. These parameter estimates from the underlying inhomogeneous Neyman-Scott point process can subsequently be used to compute local estimates of expected plant density. 

Habitat fragmentation, driven by forestry and land-use changes, threatens biodiversity in boreal Sweden. While most forests in this region are heavily managed, historical forestry intensity varies geographically, with more intact old-growth forests remaining in mountain regions. Saproxylic polypores and epiphytic lichens, reliant on deadwood and old trees, are particularly sensitive to these changes. We surveyed 26 woodland key habitats in boreal Sweden, analysing total and red-listed species of wood fungi and epiphytic lichens, including functional traits relevant to fragmentation sensitivity. Landscape structure was assessed at three spatial scales (0.5, 5, 15 km), capturing habitat amount, quality, and geographic gradients reflecting historical forestry. Local environmental conditions were also evaluated. Local-scale factors were the strongest drivers of species richness: deadwood volume was critical for fungi, while tree age and stand size were key drivers for lichens. Landscape level effects were less pronounced. Total polypore richness and several of the fungal functional groups responded to landscape structure at either immediate (0–5 km) or broader (5–15 km) scales, while lichen richness was not affected by the measured landscape parameters. Both polypore and lichen communities reflected influence from past forestry and current stand structure. These findings underscore that expanding forest area alone is insufficient unless structural complexity and deadwood availability improves. Conservation efforts should prioritize preserving and restoring mature forest patches to sustain fungal and lichen diversity in managed boreal landscapes.

Decision-making on biodiversity and ecosystem services depends on relevant knowledge and information. As the topic is complex and includes different knowledge systems, worldviews, and the interaction between human societies and the natural world, there is a need for experts from different fields to provide support to decision makers. The Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES) was established to fill the perceived science-policy gap. IPBES has four defined functions: capacity building; knowledge generation catalysis; assessments; and policy support. Its program addresses these functions utilizing a conceptual framework allowing a coherent treatment of knowledge transfer. Although significant progress is made, IPBES faces challenges that include: providing policy-relevant but not policy-prescriptive information; achieving disciplinary; gender and geographic balance; and blending scientific disciplines with other knowledge systems. IPBES is a global process that attempts to translate knowledge into a format that makes sense to decision makers and being politically recognized; that is, bridging science and policy. 

Introduction: Rising demand for forest products, climate mitigation, and ecosystem restoration has driven international pledges to expand forests, mostly on abandoned agricultural lands and areas of low conservation value. According to a recent survey among restoration practitioners across Europe, optimal planting designs and densities are key questions for reforestation efforts. Objectives: We aimed to determine how planting density affects the performance of reforestation/afforestation plantings, how these effects vary by climate, species types, and stand age, and whether there are planting density thresholds triggering significant performance shifts. Methods: Using both descriptive statistics and meta-analyses, we systematically reviewed 120 studies from temperate and boreal forests to analyze planting density effects on the performance of tree plantings. Results: Higher planting densities increase overall yield but also mortality. Negative effects on individual stem growth occur mainly at early ages, while negative impacts on individual stem growth and survival intensify over time. Benefits on stand yield are observed at both young and old ages, and there are no clear differences in the density response of shade-tolerant and shade-intolerant species. On average, an increase in planting density of 71 and 118% is needed to cause significant impacts on performance at stand-level and individual-tree level, respectively, though effects vary across studies and variables. Conclusions: Observed patterns aligned with expectations, as higher planting densities increased mortality and lowered individual growth while promoting overall yields. However, the timing and thresholds of positive and negative effects vary, presenting opportunities to optimize management through variable densities over time. 

Forestry in boreal Sweden has significantly altered the landscape and reduced old-growth forests, promoting growth of younger, managed stands. Saproxylic polypores are in direct competition with forestry for resources and have declined significantly in diversity. These fungi play a crucial role in decomposing deadwood with their persistence reliant on habitat quality, connectivity, and continuous wood availability. We examined how log, stand, and landscape-level factors affect saproxylic polypore richness and community composition in 26 woodland key habitats (WKHs) in southern boreal Sweden. We recorded polypore fruitbodies on 1263 Picea abies deadwood units and assessed stand structure. GIS was used to quantify spruce forest amount and quality at 0.5, 5, and 15 km scales, including connections to larger high-quality habitats. Local-scale factors, especially deadwood volume and decay stage, strongly influenced fungal richness. Landscape effects were weaker, likely due to the homogenous and degraded surrounding forest matrix. However, polypore richness increased with high-quality forest cover at the 15 km scale, while medium-quality forest at 5 km had a negative effect. Red-listed species richness showed a strong eastward gradient, possibly reflecting historical forestry and extinction debt. Community composition patterns aligned with these trends, with further indirect effects from nearby forest amount and quality. We conclude that the landscape configuration matters but is context dependant. In our heavily managed study region, high-quality patches like WKHs are too isolated, leaving local conditions as the primary driver of fungal persistence. Effective conservation requires integrating landscape-scale measures, including identifying and protecting remaining forests with high natural values. 

Despite increasing evidence suggesting mixed-species plantations promote biodiversity, a comprehensive quantitative analysis of this knowledge is lacking. We systematically reviewed 71 studies to evaluate the effects of mixed versus pure tree plantations on biodiversity. Using descriptive statistics and meta-analyses, we explored: a) the effects of mixed plantations on forest-related biodiversity; b) variations in these effects with climate, stand age, and with the richness, relative abundance, and functional diversity of the planted species; and c) differences in responses across taxonomic and functional groups. Our meta-analyses revealed a significant positive effect of mixed-species plantations on taxonomic diversity. However, most observations (64%) reported no significant effects. Positive effects are more frequent in mixtures with more than two species (49%), compared to two-species mixtures (29%), and were strongest in tropical climates (78%), followed by temperate (26%) and continental climates (14%). Among taxonomic and functional groups, positive mixing effects are most frequent for birds (75%), followed by litter microbiota (47%), understory plants (40%), and above-ground arthropods (29%), while soil-dwelling micro-organisms (22%) and soil mesofauna (4%) appear less sensitive. Mixing conifers and broadleaves does not enhance biodiversity benefits, suggesting higher functional diversity may be better achieved by targeting specific species and traits. The limited effects of mixing observed in some cases may reflect the young age of plantations studied (11±9.4 years on average), which may limit the time for biodiversity to respond. The variability in biodiversity outcomes highlights the need for tailored mixing strategies and further research across broader plantation ages, settings, and underrepresented taxonomic groups to optimize biodiversity benefits in mixed-species plantations. 

In forest regions worldwide, the extent of industrial forestry footprint challenges biodiversity conservation and calls for advanced protection and ecological restoration. The conservation efficiency of protected areas needs to be improved, and forest ecosystems need to be set in a state that favors biodiversity, resilience, and provisioning of ecosystem services. Sweden hosts a large share of the European forests, with dominance of non-industrial forest ownership and extensive forestry footprint, hence with a strong need for expanded conservation, restoration, and multiple-use targets. Protection through voluntary Nature Conservation Agreements and regulated Biotope Protection Areas exists since the 1990s, supported by economic compensation to landowners. Across entire Sweden and all ecoregions, we assessed their abundance over a 30-year period, including forest types, restoration practices, rotation intervals, and selection of tree species. These nearly 14,000 patches covering over 70,000 ha are small with a median area of 3-4 ha and rarely larger than 20 ha. Their contribution is important, particularly in southern Sweden with low and fragmented forest cover distributed among many different owners. A decreasing trend in protection is alarming since these contribute to representative forest type across the forest landscape of Sweden. Active restoration dominates over passive set-asides; coniferous forest types are less represented than more rare forest types, many different tree species are favored, and different restoration practices occur, but with few dominating. While recognizing the important contribution, we find that the restoration practices are narrow and repetitive and that a greater diversification is needed to improve conservation and multiple-use targets of forests.

This paper examines the EU Nature Restoration Regulation (NRR) as a novel framework aimed at promoting biodiversity, ecosystem services, sustainable forestry practices and resilient ecosystems. We highlight the Swedish forests' pivotal role in realizing the NRR goals given the substantial forest area and forest value capital, as well as the urgent need for ecological restoration, diversified forest management, and climate change adaptation in forestry. We highlight key NRR provisions, particularly Articles 4 and 12 that set quantitative restoration targets for forest habitat types and general restoration practices in forests. We note political resistance manifested in conservative interpretations that risk to compromise conservation and sustainable forest management in the future. Finally, we consider strategic, tactical, and operational NRR implementation challenges, emphasizing the importance of a comprehensive national restoration plan that integrates scientific evidence on restoration needs and the financial opportunities to secure long-term ecological and economic benefits for forest owners.