Natural populations of trees and shrubs are adapted to the climate. According to current models, our climate will become warmer on average and the risk of extreme climatic conditions will increase, including longer summer droughts. Therefore, the adaptability of trees and shrubs to changing growing conditions is important. We particularly wish to study the different origins/genotypes within the species. Through existing and new field trials, we will visualise the adaptive capacity of different genetic entities by carrying out observations in years with different climatic conditions, and in field trials that were set up on very different sites.