Interpreting wind damage risk-how multifunctional forest management impacts standing timber at risk of wind felling

Landscape multifunctionality, a widely accepted challenge for boreal forests, aims to simultaneously provide timber, non-timber ecosystem services, and shelter for biodiversity. However, multifunctionality requires the use of novel forest management regimes optimally combined over the landscape, and an increased share of sets asides. It remains unclear how this combination will shape stand vulnerability to wind disturbances and exposed timber volume. We combined forest growth simulations and multi-objective optimization to create alternative landscape level forest management scenarios. Management choices were restricted to 1) rotation forestry, 2) continuous cover forestry, and 3) all regimes allowed over a harvest intensity gradient from completely set aside landscapes to maximal economic gain. Estimates for the stands' structural and environmental characteristics were used to predict the stand level wind damage probability. We evaluated averaged wind-exposed standing timber volume and changing forest structure under management scenarios. Intensive rotation forestry reduced tree heights and wind damage risk, but also reduced landscape multifunctionality. Conversely, continuous cover forestry maintained multifunctionality but increased wind damage probability due to taller trees and higher thinning frequency. Overall, continuous cover forestry lowers the total volume of wind exposed timber at any given time compared with rotation forestry. Nevertheless, a selective application of rotation forestry contributes to high economic gains and increases landscape heterogeneity. A combination of management approaches across landscapes provides an efficient way to reduce the amount of wind-exposed timber volume while also increasing habitat for vertebrate and non-vertebrate species and satisfying high timber demands

Sectoral policies cause incoherence in forest management and ecosystem service provisioning

Various national policies guide forest use, but often with competing policy objectives leading to divergent management paradigms. Incoherent policies may negatively impact the sustainable provision of forest ecosystem services (FES), and forest multifunctionality. There is uncertainty among policymakers about the impacts of policies on the real world. We translated the policy documents of Finland into scenarios including the quantitative demands for FES, representing: the national forest strategy (NFS), the biodiversity strategy (BDS), and the bioeconomy strategy (BES). We simulated a Finland-wide systematic sample of forest stands with alternative management regimes and climate change. Finally, we used multi-objective optimization to identify the combination of management regimes matching best with each policy scenario and analysed their long-term effects on FES.The NFS scenario proved to be the most multifunctional, targeting the highest number of FES, while the BES had the lowest FES targets. However, the NFS was strongly oriented towards the value chain of wood and bioenergy and had a dominating economic growth target, which caused strong within-policy conflicts and hindered reaching biodiversity targets. The BDS and BES scenarios were instead more consistent but showed either sustainability gaps in terms of providing timber resources (BDS) or no improvements in forest biodiversity (BES). All policy scenarios resulted in forest management programs dominated by continuous cover forestry, set-aside areas, and intensive management zones, with proportions depending on the policy focus. Our results highlight for the first time the conflicts among national sectoral policies in terms of management requirements and effects on forest multifunctionality. The outcomes provide leverage points for policymakers to increase coherence among future policies and improve implementation of multiple uses of forests

Integrating wind disturbances into forest planning: a stochastic programming approach

Forest disturbances challenge our ability to carefully plan for sustainable use of forest resources. As forest disturbances are stochastic, we cannot plan for the disturbance at any specific time or location. However, we can prepare for the possibility of a disturbance by integrating its potential intensity range and frequency when developing forest management plans. This study uses stochastic programming to integrate wind intensity (wind speed) and wind event frequency (number of occurrences) into the forest planning process on a small coastal Finnish forest landscape. We used a mechanistic model to quantify the critical wind speed for tree felling, with a Monte Carlo approach to include wind damage and salvage logging into forest management alternatives. We apply a stochastic programming model to explore two objectives: maximizing the expected forest net present value or maximizing the even-flow of income. To assess the effects of improper wind risk assumptions in planning, we compare the results when optimizing for correct versus incorrect wind intensity and frequency assumptions. When maximizing for net present value, the impacts of misidentifying wind intensity and frequency are minor, likely due to harvests planned immediately as trees reach maturity. For the case when maximizing even-flow of income, incorrectly identifying wind intensity and frequency severely impacts the ability to meet the required harvest targets and reduces the expected net present value. The specific utility of risk mitigation therefore depends on the planning problem. Overall, we show that incorporating wind disturbances into forest planning can inform forest owners about how they can manage wind risk based on their specific risk preferences

Choosy beetles : How host trees and southern boreal forest naturalness may determine dead wood beetle communities

Wood-living beetles make up a large proportion of forest biodiversity and contribute to important ecosystem services, including decomposition. Beetle communities in managed southern boreal forests are less species rich than in natural and near-natural forest stands. In addition, many beetle species rely primarily on specific tree species. Yet, the associations between individual beetle species, forest management category, and tree species are seldom quantified, even for red-listed beetles. We compiled a beetle capture dataset from flight intercept traps placed on Norway spruce (Picea abies), oak (Quercus sp.), and Eurasian aspen (Populus tremulae) trees in 413 sites in mature managed forest, near-natural forest, and clear-cuts in southeastern Norway. We used joint species distribution models to estimate the strength of associations for 368 saproxylic beetle species (including 20 vulnerable, endangered, or critical red-listed species) for each forest management category and tree species. Tree species on which traps were mounted had the largest effect on beetle communities; oaks had the most highly associated beetle species, including most of the red-listed species, followed by Norway spruce and Eurasian aspen. Most beetle species were more likely to be captured in near-natural than in mature managed forest. Our estimated associations were compatible ? for many species ? with categorical classifications found in several existing databases of saproxylic beetle preferences. These quantitative beetle-habitat associations will improve future analyses that have typically relied on categorical classifications. Our results highlight the need to prioritize conservation of near-natural forests and oak trees in Scandinavia to protect the habitat of many red-listed species in particular. Furthermore, we underline the importance of carefully considering the species of trees on which traps are mounted in order to representatively sample beetle communities in forest stands.Peer reviewe

High-resolution 3D forest structure explains ecomorphological trait variation in assemblages of saproxylic beetles

Climate, topography and the 3D structure of forests are major drivers affecting local species communities. However, little is known about how the specific functional traits of saproxylic (wood-living) beetles, involved in the recycling of wood, might be affected by those environmental characteristics. Here, we combine ecological and morphological traits available for saproxylic beetles and airborne laser scanning (ALS) data in Bayesian trait-based joint species distribution models to study how traits drive the distributions of more than 230 species in temperate forests of Europe. We found that elevation (as a proxy for temperature and precipitation) and the proportion of conifers played important roles in species occurrences while variables related to habitat heterogeneity and forest complexity were less relevant. Furthermore, we showed that local communities were shaped by environmental variation primarily through their ecological traits whereas morphological traits were involved only marginally. As predicted, ecological traits influenced species' responses to forest structure, and to other environmental variation, with canopy niche, wood decay niche and host preference as the most important ecological traits. Conversely, no links between morphological traits and environmental characteristics were observed. Both models, however, revealed strong phylogenetic signal in species' response to environmental characteristics. These findings imply that alterations of climate and tree species composition have the potential to alter saproxylic beetle communities in temperate forests. Additionally, ecological traits help explain species' responses to environmental characteristics and thus should prove useful in predicting their responses to future change. It remains challenging, however, to link simple morphological traits to species' complex ecological niches. Read the free Plain Language Summary for this article on the Journal blog

Traits mediate niches and co-occurrences of forest beetles in ways that differ among bioclimatic regions

Aim The aim of this study was to investigate the role of traits in beetle community assembly and test for consistency in these effects among several bioclimatic regions. We asked (1) whether traits predicted species' responses to environmental gradients (i.e. their niches), (2) whether these same traits could predict co-occurrence patterns and (3) how consistent were niches and the role of traits among study regions. Location Boreal forests in Norway and Finland, temperate forests in Germany. Taxon Wood-living (saproxylic) beetles. Methods We compiled capture records of 468 wood-living beetle species from the three regions, along with nine morphological and ecological species traits. Eight climatic and forest covariates were also collected. We used Bayesian hierarchical joint species distribution models to estimate the influence of traits and phylogeny on species' niches. We also tested for correlations between species associations and trait similarity. Finally, we compared species niches and the effects of traits among study regions. Results Traits explained some of the variability in species' niches, but their effects differed among study regions. However, substantial phylogenetic signal in species niches implies that unmeasured but phylogenetically structured traits have a stronger effect. Degree of trait similarity was correlated with species associations but depended idiosyncratically on the trait and region. Species niches were much more consistent-widespread taxa often responded similarly to an environmental gradient in each region. Main conclusions The inconsistent effects of traits among regions limit their current use in understanding beetle community assembly. Phylogenetic signal in niches, however, implies that better predictive traits can eventually be identified. Consistency of species niches among regions means niches may remain relatively stable under future climate and land use changes; this lends credibility to predictive distribution models based on future climate projections but may imply that species' scope for short-term adaptation is limited.Peer reviewe

Disentangling the effects of management and climate change on habitat suitability for saproxylic species in boreal forests

Peer reviewe

Sectoral policies cause incoherence in forest management and ecosystem service provisioning

Various national policies guide forest use, but often with competing policy objectives leading to divergent management paradigms. Incoherent policies may negatively impact the sustainable provision of forest ecosystem services (FES), and forest multifunctionality. There is uncertainty among policymakers about the impacts of policies on the real world. We translated the policy documents of Finland into scenarios including the quantitative demands for FES, representing: the national forest strategy (NFS), the biodiversity strategy (BDS), and the bioeconomy strategy (BES). We simulated a Finland-wide systematic sample of forest stands with alternative management regimes and climate change. Finally, we used multi-objective optimization to identify the combination of management regimes matching best with each policy scenario and analysed their long-term effects on FES. The NFS scenario proved to be the most multifunctional, targeting the highest number of FES, while the BES had the lowest FES targets. However, the NFS was strongly oriented towards the value chain of wood and bioenergy and had a dominating economic growth target, which caused strong within-policy conflicts and hindered reaching biodiversity targets. The BDS and BES scenarios were instead more consistent but showed either sustainability gaps in terms of providing timber resources (BDS) or no improvements in forest biodiversity (BES). All policy scenarios resulted in forest management programs dominated by continuous cover forestry, set-aside areas, and intensive management zones, with proportions depending on the policy focus. Our results highlight for the first time the conflicts among national sectoral policies in terms of management requirements and effects on forest multifunctionality. The outcomes provide leverage points for policymakers to increase coherence among future policies and improve implementation of multiple uses of forests

Forests for Health Promotion: Future Developments of Salutogenic Properties in Managed Boreal Forests

Visits to forests can improve human health and well-being through various mechanisms. They can support the immune system, promote physical activity, and restore stress and attention fatigue. Questions remain about how perceived qualities in forests important to support such salutogenic, i.e., health-promoting, benefits can be represented in forest simulation tools to allow quantitative analyses, e.g., long-term projections or trade-off analyses with other forest functions, such as biodiversity conservation, wood production, etc. Questions also remain about how different forest management regimes might impact such perceived qualities in forests. Here, we defined three types of salutogenic forest characteristics (SFCs), referred to as Deep, Spacious, and Mixed forest characteristics, respectively. We did so by using the perceived sensory dimension (PSD) model, which describes and interrelates more fundamental perceived qualities of recreational outdoor environments that are important to support people’s health and well-being. We identified proxy variables for the selected PSD models in boreal forest stands and compared the effect of five different management regimes on both individual PSD models and the derived SFCs when projecting a forest landscape 100 years into the future. Our results suggest combinations of protection (set-aside) and variations of continuous cover forestry as the most promising strategies to achieve these salutogenic properties in the long-term future. Depending on the SFC in focus and the specific management regime used, between 20% and 50% of the landscape could support associated properties in the long term (100 years). This might impact how forests should be managed when salutogenic outcomes are considered alongside, e.g., wood production and other forest contributions