Forest planning to reduce disturbance damage in the context of climate change

In recent years, there has been a strong focus on how forests can mitigate climate change and sustainably provide ecosystem services. In this context, natural disturbances have gained importance, as severe disturbances may pose a threat to the provision of ecosystem services such as timber production. This thesis expands our understanding of how forest management planning can mitigate forest susceptibility to disturbance by investigating the connection between well-known management strategies and their influence on the forests’ susceptibility to damage by major natural disturbances in Sweden. In addition, the thesis presents new forest planning models specifically addressing European spruce bark beetle insect and wind damage, given their importance in Sweden. The forest planning models developed in the research underlying this thesis use exact optimization methods to achieve specific spatial forest characteristics enhancing resistance to natural disturbances by identifying the optimal management for each stand in the landscape over the planning horizon. To reduce the forest's susceptibility to spruce bark beetle attacks, management strategies should prioritize shorter rotation periods and incorporate mixed-species stands. In contrast, to reduce forest susceptibility to wind damage, it is important to reduce the length of forest edges exposed to wind as well as avoid undertaking final harvests near mature stands to help in maintaining shelter between forest stands. The studies in this thesis reveal that adaptation costs can affect net present value and total harvest volumes by 5 to 10%, reducing substantially forest susceptibility. To conclude, the understanding of each type of disturbance is of the utmost importance for adapting forest management to either reduce or promote specific forest characteristics that affect susceptibility. This thesis shows that, with well-oriented forest management planning, there are good opportunities to reduce susceptibility to damage from natural disturbances.