Between past and future: legacy and fate of an important centre of endemism for the Mediterranean region

Climate change is one of the greatest threats to biodiversity, particularly in mountain ecosystems, which often show high endemism rate. Studies on past climate changes suggested that current centers of endemism are placed where climatic fluctuations were less pronounced (because of mountainous topography) and that these areas will be less affected by climate change in the future (1). However, this doesn’t mean that these areas will not experience drastic climate change effects; in fact, several evidences indicate that mountain endemics are disproportionally exposed to climate change, because usually they are characterized by small range size, narrow ecological tolerance and poor dispersal ability (2). SW Alps are one the most important centers of endemism of the Mediterranean Basin and are particularly exposed to climate change threat due to the contemporaneous effects of temperature increase and precipitation decrease, as other Southern European mountain systems (3). Taking into account dispersal abilities, we used Species Distribution Models to analyze the distribution of suitable climatic conditions for 100 plant species endemic or subendemic of SW Alps (about 60% of endemisms of this area). We projected predicted suitability in past (i.e.: last interglacial, last glacial maximum, middle Holocene), current and future (i.e: year 2070) time slices. For each time slice we elaborate a map of potential species richness; for each species we also calculated the percentage of range loss and gain in the future, considering both optimistic and pessimistic emission scenarios.