The concept of BACCARA is to construct a three-dimensional risk assessment model linking climate change, functional diversity, and forest productivity. It will be built up using the following three steps of deductive reasoning:
- The effect of climate change on forest biodiversity will be evaluated through better understanding of the ecological processes that shape species composition and are particularly sensitive to climate conditions. Forest species composition will be determined as the assemblage of tree species and both mutualistic and antagonistic species that drive tree species composition. Climate conditions will include both average and extreme values of climatic variables (e.g. temperature, humidity and wind).
- The relationships between forest biodiversity and functioning will be deciphered through better understanding of the respective role of tree species richness and composition and by focussing on the biotic interactions between species. Energy flows (i.e. resource production and consumption) across different trophic levels (trees and mutualists as producers, herbivores and pathogens as consumers) will be analysed since the fundamental ecological hypothesis behind the diversity–productivity relationship is the optimal use of resources.
- The information will eventually be aggregated to predict the effect of climate change on forest productivity through changes in tree species composition. The prediction will be expressed as a risk of forest productivity loss, considered as a function of climate change scenario probability, susceptibility of forest to climate change according to its composition, and forest biomass productivity according to its composition.
In each step, we will focus on fundamental ecological processes at work to deliver more generic scientific outcomes enabling easier generalization to diverse types of European forest and forest manager expectations than found in a case by case approach.