Multifunctional forests and their risks under climate change

Abstract

Finnish forests are facing challenges from climate change and increasing natural disturbances while demands for the provisioning of diverse ecosystem services should be ensured. Resilient, multifunctional forests are therefore needed for the future. Future multipurpose forests and their disturbance risk in the changing climate (FOSTER) -project investigated the impacts of climate change and natural disturbance agents on forests as well as the synergies and trade-offs between ecosystem services under multiple alternative forest management scenarios. We found significant impacts of disturbances and climate change on forests. Impacts of disturbance agents, such as wind, spruce bark beetle, and ungulate browsers, are likely to increase in the future. Impacts of deer species (whitetail deer, roe deer) with expanding distribution ranges and increasing populations may have unexpected impacts on forest ecosystems. Climate change interacts with disturbances and exacerbates disturbance effects, specifically in the case of bark beetles. FOSTER also explored the potential effects of micro-climate on forest disturbances and how to take them into account in modelling. Using a multi-model approach, various forest management and land-use scenarios were simulated for both smaller landscapes (long-term simulations including climate change and disturbances) and larger regions (short-term, current climate simulations). The simulation results indicate that mitigation management can increase carbon storage and support biodiversity but carry higher disturbance risks and considerably reduce harvested volumes. Conversely, adaptation-focused management was less beneficial for carbon storage but yielded higher harvests. The adaptation scenarios aimed to reduce disturbance risks were effective in reducing bark beetle risk under climate change. The FOSTER project has brought together forests disturbance, climate change and forest management expertise and applied complex modelling approaches to understand the future of Finnish forests. The results show that impacts of changing climate and disturbances may be substantial. Thus, the future forest management should include actions to not only mitigate climate change, but also prepare for adaption to the dramatic changes it may bring in order to ensure resilient ecosystem-provisioning in the future.