Modelling the current and future biodiversity distribution in the Chilean Mediterranean hotspot. The role of protected areas network in a warmer future

Aim: Mediterranean Chile is part of the five recognized mediterranean-type climates in the world and harbours a very rich floral diversity. Climate change has been reported as a significant threat to its biodiversity. We used the flora of Mediterranean Chile to analyse how biodiversity patterns, as measured by phylogenetic diversity, genus and species richness will respond to climate change scenarios and identify the areas that will harbour the greatest evolutionary potential and biodiversity richness. We also evaluated how these spatial patterns are depicted within the current network of protected areas. Location: Chilean Mediterranean climate-type Region, South America. Methods: Biodiversity metrics were evaluated for current and future climatic scenarios. Species distribution models were done using Maxent for 1.727 species and 571 genera. Relationships between species/genera gain, loss and turnover were evaluated. For Mediterranean endemic species, loss and gain were also related to life-form. Finally, variation in species gain, loss and turnover was evaluated in future climate change scenarios within and outside Mediterranean Chile state protected areas. Results: We found a general decrease in species richness in the entire Region towards future climate change scenarios. Phylogenetic diversity is predicted to be higher than expected by richness in the north–south of the area and lower than expected by richness in the Andes Mountain. The highest average species and genus loss is predicted to occur outside the protected areas; meanwhile, species and genus gain is higher within them. Main conclusions: Future biodiversity patterns are reported here for the first time in the Chilean Mediterranean Region. Our findings enhance the importance of the current protected areas to harbour this future variation, despite their reduced number and size along the region