Brain-be ''Forbio climate'' Adaptation potential of biodiverse forests in the face of climate change.

Context Climate change is expected to have a large impact on the distribution, composition and functioning of forest ecosystems worldwide as trees have only little opportunities to migrate and adaptation via natural selection happens very slowly. Hence, creating resistant and resilient forests is a key challenge for forest management. More insight into the adaptive capacity of trees and forests in their consecutive life and development stages, respectively, and the potential buffering effect of tree species admixing to climate change is thus urgently needed. Objectives FORBIO Climate aimed at scrutinizing the adaptive capacity of pedunculate and sessile oak (Quercus robur and Q. petraea, respectively) and European beech (Fagus sylvatica) and at predicting the future performance of these tree species in Belgium under climate change. More specifically, the project aimed at testing the following hypotheses: (1) epigenetic inheritance mechanisms can increase the adaptive capacity of trees to climate change during the reproduction stage; (2) across subsequent tree development stages, tree performance is more resistant and resilient to climate change in more biodiverse forests. Conclusions Belgian’s future climate is projected to be warmer, with a higher frequency of extreme precipitation events. Parental temperature influenced the germination success, bud phenology and growth of oak and beech seedlings, but we did not observe DNA methylation that could help to explain the phenological change mediated by the parental temperature. Studies on both saplings and mature trees suggested that drought may influence ecosystem processes in young and mature forests, affecting the growth and vitality of trees. Despite the high awareness of climate change as an issue in forest management and the need to adjust management practices, we found a lack of knowledge on how to adapt forest management in order to mitigate the vulnerability of forests under changing climate conditions. The results of this project confirm that admixing tree species in oak and beech stands is a good adaptation measure across all forest development stages