Future distributions of Madagascar’s endemic plant species

Background/Question/Methods

Climate change is affecting species distributions worldwide. This is especially true in tropical regions such as Madagascar, where anthropogenic pressures have magnified the vulnerability of several species. We analyzed the potential impact of climate change on 10 threatened endemic plant species of the genera Mediusella and Xerochlamys in Madagascar. We developed potential distribution models using 19 climatic variables for the present and future (2050) using three general circulation models (CCCMA, CSIRO, HANDLEY) and two climate scenarios (A2 and B2). We also assessed patterns of range shift by comparing present and future distributions under the different models and scenarios.

Results/Conclusions

Most species were predicted to undergo major range contraction due to climate change, particularly species in the Central High Plateau. Here, species were predicted to experience the highest habitat loss, with narrow-range species being the most sensitive. A southward potential distribution was predicted for species distributed in the northwest, whereas upland potential distribution was predicted for some central species. Future climate change will drastically affect the distribution of our target species, seven of which will experience major range contraction by 2050. Among these, threatened endemic species will face higher risk of extinction due to habitat loss. Range expansion was also predicted for two species. In any case, species’ adaptation to a changing climate may not occur quickly enough to offset these projections, emphasizing the need to strengthen current conservation efforts, especially in areas where species are most likely to persist.