Global change is modifying temperatures, the concentration of carbon dioxide in the air and rainfall patterns, all factors which regulate the functioning of forests. To adapt the management of forest stands to these environmental changes, the FORADAPT project - Assessing the potential of forest adaptation to climate change, has been focusing on producing a better understanding of the vulnerability of trees. For this, teams of INRAE ecophysiologists, geneticists and ecologists, alongside forest managers, have worked together to summarise and improve existing knowledge, develop databases and create modelling and prediction tools.
The importance of individual variability
The adaptation of trees and forests to climate change is played out at three levels: phenotypic plasticity, which represents a tree’s capacity to acclimatise during its lifetime, the genetic evolution of populations, which addresses natural selection, and the migration or replacement of one species by another.
“We have seen that the migration rate was too slow compared to the speed of climate change,” says Hendrik Davi, project spokesperson. “And it’s the same for genetic evolution: through modelling we have demonstrated that it takes at least five generations for genetic divergence to take place. Again, it’s too long!”
There remains then phenotypic plasticity, the intrinsic capacity of an individual to adapt to a changing environment. “Trees have a very large architectural plasticity, which, for example, allows them to draw water almost from the water table if conditions are very dry,” explains the researcher.
Prediction for better adaptation
All this knowledge has made it possible to create a tool for researchers and forest managers. The objective is to predict the presence or absence of a forest species based on climate data. “We needed a tool that takes physiological, demographic and genetic data into account, in order to offer adaptation solutions,” says Hendrik. “Several forest management options can be tested to provide managers with information on the type of adaptation to be carried out: maintaining the species already in place by optimising their silviculture, or replacing them with more suitable species.” Currently usable only by researchers, in the future a user-friendly interface will be developed providing a tool to help the decision-making of forest managers. Ultimately, the tool will also integrate economic and social dimensions to cover all the services rendered by forests.
- Boiffin, J., Badeau, V., Bréda, N., 2017. Species distribution models may misdirect assisted migration: insights from the introduction of Douglas-fir to Europe. Ecological Applications 27, 446–457.
- Davi H, Cailleret, M. 2017. Assessing drought-driven mortality with a process-based model. Agricultural and Forest Meteorology 232 (2017) 279–290.