Forest adaptation to climate change - options and limitations

Forests are particularly affected by climate change since trees, as long-living and immovable organisms, have to adapt to environmental change over periods of 100 years and more. Reports on the projected increase of drought, heat and storm hazards make the development and application of adaptation strategies urgent: (1) Conservation of forest structures against increasing succession pressure increases the risk of catastrophic loss of forests (drought damage, wind throw) depending on the degree of local climate and site change. (2) Active adaptation, like the replacement of drought-sensitive tree species by less sensitive species or provenances, can lower the damage risk for forests. For this purpose, however, information on the regional und local adaptation and adaptability to future climate conditions is needed. (3) Passive adaptation with the deliberate use of spontaneous adaptation processes (natural succession and species migration) is the lowest-risk option, but eliminates the possibility of following specific forest management targets. The use of provenances of native and non-native tree species (e. g. Douglas fir) from regions with a climate corresponding to future climate in Germany is an important element of active adaptation. Provenance trials induced by forest genetic science that have been running for decades provide valuable basic information on adaptation of tree provenances. An integrative concept for adaptation is presented that inter-links focussed research and political processes from international to local scale.