Evaluation of Growth Simulators for Forest Management in Terms of Functionality and Software Structure Using AHP

A range of computer models exist for simulating forest growth, with different model functions, spatial resolutions and regional calibration specifications. Choosing a suitable simulator is difficult due to its abundance and complexity. The aim of the project is to evaluate a simulator that could be adapted to conditions in Switzerland and used to support decision‐making processes in both forest enterprises and scientific contexts. Fourteen potentially suitable forest growth simulators were identified through a literature review, which was then narrowed down to four: BWINPro, SILVA, MOSES and PrognAus. In the second phase, these were systematically evaluated in terms of functionality and software structure using AHP, in order to identify a suitable simulator. The AHP evaluation entailed: (1) determining the decision criteria and hierarchy, (2) performing pairwise comparisons and calculating the utility values and (3) conducting a sensitivity analysis. AHP was found to provide a transparent, verifiable evaluation process for simulator selection. This enabled a critical argumentation and assessment of the simulators. In the third phase, not covered by this article, the selected simulator will be parametrised for Swiss conditions and incorporated into an overarching decision‐support system for forest planning and management

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

Diversification of forest management can mitigate wind damage risk and maintain biodiversity

Mitigating future forest risks, safeguarding timber revenues and improving biodiversity are key considerations for current boreal forest management. Alternatives to rotation forestry likely have an important role, but how they will perform under a changing climate remains unclear. We used a boreal forest growth simulator to explore how variations on traditional clear-cutting, in rotation length, thinning intensity, and increasing number of remaining trees after final harvest (green tree retention), and on extent of continuous cover forestry will affect stand-level probability of wind damage, timber production, deadwood volume, and habitats for forest species. We used business-as-usual rotation forestry as a baseline and compared alternative management adaptations under the reference and two climate change scenarios. Climate change increased overall timber production and had lower impacts on biodiversity compared to management adaptations. Shortening the rotation length reduced the probability of wind damage compared to business-as-usual, but also decreased both deadwood volume and suitable habitats for our focal species. Continuous cover forestry, and management with refraining from thinnings, and extension of rotation length represent complementary approaches benefiting biodiversity, with respective effects of improving timber revenues, reducing wind damage risk, and benefiting old-growth forest structures. However, extensive application of rotation length shortening to mitigate wind damage risk may be detrimental for forest biodiversity. To safeguard forest biodiversity over the landscape, shortening of the rotation length could be complemented with widespread application of regimes promoting old-growth forest structures

Enhancing Resilience of Boreal Forests Through Management Under Global Change: a Review

Purpose of Review Boreal forests provide a wide range of ecosystem services that are important to society. The boreal biome is experiencing the highest rates of warming on the planet and increasing demand for forest products. Here, we review how changes in climate and its associated extreme events (e.g., windstorms) are putting at risk the capacity of these forests to continue providing ecosystem services. We further analyze the role of forest management to increase forest resilience to the combined effects of climate change and extreme events. Recent Findings Enhancing forest resilience recently gained a lot of interest from theoretical perspective. Yet, it remains unclear how to translate the theoretical knowledge into practice and how to operationalize boreal forest management to maintain forest ecosystem services and functions under changing global conditions. We identify and summarize the main management approaches (natural disturbance emulation, landscape functional zoning, functional complex network, and climate-smart forestry) that can promote forest resilience. Summary We review the concept of resilience in forest sciences, how extreme events may put boreal forests at risk, and how management can alleviate or promote such risks. We found that the combined effects of increased temperatures and extreme events are having negative impacts on forests. Then, we discuss how the main management approaches could enhance forest resilience and multifunctionality (simultaneous provision of high levels of multiple ecosystem services and species habitats). Finally, we identify the complementary strengths of individual approaches and report challenges on how to implement them in practice

Sectoral policies as drivers of forest management and ecosystems services: A case study in Bavaria, Germany

European countries have national sectoral polices to regulate and promote the provision of a wide range of forest ecosystems services (FES). However, potential incoherencies among these policies can negatively affect the efficient provision of FES. In this work, we evaluated the coherence among three national policies from Germany and their ability to effectively provide FES in the future: the Forest Strategy 2020 (FS), the National Strategy on Biological Diversity (BDS), and the German National Policy Strategy on Bioeconomy (BES). Using forest inventory data from the Federal State of Bavaria, we simulated a range of forest management options under three climate trajectories for 100 years into the future (2012–2112). Then, with multi-objective optimization, we translated each policy into a specific scenario and identified the best combination of management regimes that maximizes the targets defined in each policy scenario. The three policies were vague in the definition of FES. The FS was the most comprehensive policy aiming for a higher degree of multifunctionality, whereas the BES and BDS focused on less FES. The FS and the BDS showed the highest coherence, while the BES showed a stronger focus on timber production. As a result, the optimal management programs of FS and BDS showed high integration, with a dominance of Continuous Cover Forestry (CCF), and certain shares of set asides. Climate change led to an increase of set aside areas due to increased productivity. In the BES, the share of land among management regimes was strongly segregated between CCF and rotation forestry. Our policy coherence analysis showed that achieving a multifunctional provision of FES requires policy coherence, fostering a diverse management of the landscape that mainly takes advantage of integrative management, like CCF, but also segregates important parts of the landscape for intensive use and set asides. Nevertheless, the current high standing volumes in Bavaria will pose an additional risk to implement such management.peerReviewe

Climate targets in European timber-producing countries conflict with goals on forest ecosystem services and biodiversity

The role of increased timber harvests in reaching climate mitigation targets for European countries will be limited if the protection of forest ecosystem services and biodiversity is to be achieved, suggests an empirical forest model driven by future scenarios to limit warming to 1.5 degrees C in 2100.The European Union (EU) set clear climate change mitigation targets to reach climate neutrality, accounting for forests and their woody biomass resources. We investigated the consequences of increased harvest demands resulting from EU climate targets. We analysed the impacts on national policy objectives for forest ecosystem services and biodiversity through empirical forest simulation and multi-objective optimization methods. We show that key European timber-producing countries - Finland, Sweden, Germany (Bavaria) - cannot fulfil the increased harvest demands linked to the ambitious 1.5 degrees C target. Potentials for harvest increase only exists in the studied region Norway. However, focusing on EU climate targets conflicts with several national policies and causes adverse effects on multiple ecosystem services and biodiversity. We argue that the role of forests and their timber resources in achieving climate targets and societal decarbonization should not be overstated. Our study provides insight for other European countries challenged by conflicting policies and supports policymakers

What drives forest multifunctionality in central and northern Europe? Exploring the interplay of management, climate, and policies

Forests provide a range of vital services to society and are critical habitats for biodiversity, holding inherent multifunctionality. While traditionally viewed as a byproduct of production-focused forestry, today's forest ecosystem services and biodiversity (FESB) play an essential role in several sectoral policies’ needs. Achieving policy objectives requires careful management considering the interplay of services, influenced by regional aspects and climate. Here, we examined the multifunctionality gap caused by these factors through simulation of forest management and multi-objective optimization methods across different regions - Finland, Norway, Sweden and Germany (Bavaria). To accomplish this, we tested diverse management regimes (productivity-oriented silviculture, several continuous cover forestry regimes and set asides), two climate scenarios (current and RCP 4.5) and three policy strategies (National Forest, Biodiversity and Bioeconomy Strategies). For each combination we calculated a multifunctionality metric at the landscape scale based on 5 FESB classes (biodiversity conservation, bioenergy, climate regulation, wood, water and recreation). In Germany and Norway, maximum multifunctionality was achieved by increasing the proportion of set-asides and proportionally decreasing the rest of management regimes. In Finland, maximum MF would instead require that policies address greater diversity in management, while in Sweden, the pattern was slightly different but similar to Finland. Regarding the climate scenarios, we observed that only for Sweden the difference in the provision of FESB was significant. Finally, the highest overall potential multifunctionality was observed for Sweden (National Forest scenario, with a value of 0.94 for the normalized multifunctionality metric), followed by Germany (National Forest scenario, 0.83), Finland (Bioeconomy scenario, 0.81) and Norway (National Forest scenario, 0.71). The results highlight the challenges of maximizing multifunctionality and underscore the significant influence of country-specific policies and climate change on forest management. To achieve the highest multifunctionality, strategies must be tailored to specific national landscapes, acknowledging both synergistic and conflicting FESB