The large decrease in common Beech trees in Europe over the past few decades has been mainly attributed to the increased frequency and intensity of droughts. However, the influence of local conditions such as forest structure, microclimate, soil science and topography on this decline remains unclear.
A French study addressed this question using modelling to predict the decline of Beech forests based on environmental conditions. The results show that climatic factors, particularly year-on-year variability in maximum temperature and water deficit, are the main drivers of the decline in stands.
The results therefore confirm the high sensitivity of Beech trees to high temperatures and drought. Nevertheless, other factors such as soil properties (particularly available water capacity), topography and dendrometric parameters (stand structure and composition) also influence the risk of beech decline. For instance, the study reveals that beech trees exhibit greater resilience to drought in mixed stands than in monospecific ones. Indeed, mixed stands can have a favourable effect on Beech health, particularly in areas with a Mediterranean climate. While these results are only partial, they remain valuable for forest managers, as they can use them to predict which stands are likely to decline under future climatic conditions and implement preventive silvicultural measures adapted to local site conditions.