Additive stressors call for adaptive forest management
Extreme weather events in the years 2018, 2019, and 2020 account to approximately more than 300 million m3 of damaged wood in Central Europe. Storm, fire, heat and drought, accompanied by bark beetle outbreaks impacted particularly Norway spruce forests in Germany and the Czech Republic, followed by Austria, Poland, Slovakia, Switzerland, and Northern Italy. However, other major tree species like Scots pine (Poland, Germany) and European beech (Germany, Switzerland, France) were also affected. This will likely increase under climate change with more frequent and severe weather events urging forest managers to adapt forests to increase resilience to future growing conditions. This keynote presents the concept of Adaptive Forest Management (AFM) based on the assessment of varying environmental stressors and their interactions. Adaptive potential connected to different stressors is analysed in various case studies. Drought susceptibility of seedlings shoes the potential of adaptation by provenance selection. Dendroecological studies provide a valuable tool to understand changing climate-growth correlations and differences between provenances, resulting in vulnerability maps. Bringing these results together we discuss the options and limitations of Assisted Migration as the core element of AFM, taking ecological and political aspects at a national and international scale into account.