Forest management facing climate change - an ecosystem model analysis of adaptation strategies

To adapt to climate change, forest managers request information on management options for obtaining environmental, societal and economic goals. In this study, we assess the potential of adaptive forest management to influence the productivity and storm sensitivity of nemoral and boreal forest. The forest growth across Sweden over the 21st century was simulated by the ecosystem model LPJ-GUESS, comparing four management options: 1) default forest management, 2) shorter rotation period 3) increased fraction of broadleaved trees and 4) continuous cover forestry. The simulations indicated that a management strategy implemented by a majority of forest owners can have a large-scale effect on the standing volume and risk taking. The modelled risk of storm damage, expressed as the combined effect of tree properties, ground frost and wind load, was higher in the southern than in the northern part of the country due to latitudinal variations in all three components. We conclude that whereas the probability of a significant volume loss increase with the age of a forest, the calculated economic loss can be as high in young and mid-age forest stands. To reduce the risk of storm damage and fulfil a variety of management goals, a portfolio of adaptation strategies is needed. It should include active measures such as tree-species mixtures to spread the risks and shorter rotation periods of highly exposed stands, as well as reactive measures such as salvage and sanitary cutting to reduce the risk of subsequent spruce bark beetle outbreaks.