Pedoclimatic classification of Europe as a basis for site-appropriate tree species selection in climate change

Information about soils and climate of the origin regions of the tree species is needed for the “assisted migration” of genotypes better adapted to the future climate as well as for planting of other native and non-native but better adapted tree species. Ecological classifications are seen as an important basis for “assisted migration”. However, up to now, all known approaches to classify regions of tree origin do not take into account soil properties, although soil is important for the selection of suitable origins of seed and planting material. The presented pedological-climatic classification of Central and Southern Europe can serve as a basis for a unified classification of forest growth regions that integrates soil properties for the first time. For the soil parameter of the pedoclimatic classification, the WRB soil map from the European Soil Data Centre 1:1.000.000 was used and classified for the base status of the soils. The climate was characterized by the water deficit in summer and a winter hardiness parameter. For this purpose, the CHELSA datasets for the periods 1981–2010, 2011–2040 and 2071–2100 were used, the latter with the SSP585 scenario. This gives us a 3 × 5 × 3 matrix with 45 units, with which we can fairly well map all seed and plant origins of forest tree species in Central and Southern Europe.