Les processus biologiques de réponse des arbres et forêts au changement climatique : adaptation et plasticité phénotypique.

Climate change related hazards not only impact existing forest trees in the short-term but also impact the evolutionary potential of forest stands in the long-term. Forest trees show a huge adaptive genetic diversity not only among species, but also within species among populations of different geographic origins and among individual trees within each forest stand. Furthermore, the response of individual trees to climatic fluctuations varies depending on the traits considered. Thus, trees, individually, and forests, globally, have an inherent response potential to climate change both in the short-term and in the long-term. But this potential remains limited and might not be sufficient to ensure spontaneous persistence of the forests facing climate change. Based on a description of the processes of adaptation and phenotypic plasticity, as well as their interactions, we propose a dynamic approach for the characterization and the management of so-called “genetic resources”. We argue that this dynamic and process-based approach, which integrates short-term and long-term issues, can help reason the adaptation of forests to climate change.