Changement climatique attendu et biodiversité en forêt

The authors base themselves on findings in respect of recent global warming (French Academy of Sciences) and the outlook that warming will continue in the 21st century (IPCC). They detail the consequences to be expected for plant biodiversity in forests as a result of anticipated warming, and depending on whether the changes in climate will be sudden or gradual. They underscore the fact that communities that are organised on the “niche” model will react differently to those that follow the “selection” model. They go on to examine the probable consequences of anticipated climate change for forest management. In the short term, maintenance of a high level of genetic diversity in forest stands (both at the intra- and inter-specific levels) appears to enlist a consensus. In the long term, resorting to “assisted migration” of forest tree provenances towards higher altitudes or latitudes may be inevitable, providing it is carefully thought out. Finally, the article deals with the consequences to be expected in the area of policy and measures of biodiversity conservation in forests. The static approach to conservation currently in force may lose relevance and an in-depth revision of several networks may hence become necessary (“Natura 2000” zones, protected sites, natural reserves, biotopes). It appears crucial in the future to adopt a conservation strategy that incorporates vegetation dynamics and assigns a greater role to ecological engineering. The article ends by a raising a number of considerations and recommendations relating to public biodiversity research and conservation policies.