Forest flora turnover with climate change in the Mediterranean region: A case study in Southeastern France

This study assessed the turnover in the flora due to climate change in French Mediterranean forests. This turnover was first simulated with a bioclimatic model and then controlled in the field with a flora census in 2008, in permanent plots previously surveyed in 1996-1998. The simulation quantified the potential flora turnover for various climate change scenarios. The simulated turnover in the last 30, 20 and 10 years was respectively 11%, 14% and 25%. A rapid turnover was observed in the permanent plots between the two censuses, corresponding to 14% of the initial plant composition, the last decade being exceptionally hot and dry in the study area. Despite resilience on the landscape scale and various resistance strategies, plant composition adaptation to the ongoing climate change seems to take only 20 years on a local scale. Management issues are discussed, particularly biodiversity conservation in current reserve networks, which may be inadequate to ensure long-term species persistence with the rapid shift in plant composition. Most of the areas with the highest plant species richness of the study area potentially disappear when their niche envelopes are mapped using the bioclimatic model with the climate forecasted for year 2050. (C) 2009 Elsevier B.V. All rights reserved.