Climate and landscape heterogeneity drive spatial pattern of endemic plant diversity within local hotspots in South-Eastern Alps

Identification of centers of endemism is a crucial issue to improve the understanding on overall biodiversity distribution and related conservation actions. Despite the well-known distribution of global endemic areas, less effort has been devoted in defining local hotspots and their ecological determinants. In this study, we analyzed the distribution and the spatial pattern of endemic diversity of vascular plant in the south-eastern Italian Alps, aiming at identifying the occurrence of local hotspots and focusing on the relationships occurring between alpha (i.e. species richness) and beta diversity (i.e. Local Contributors of Beta Diversity) along with their ecological and spatial drivers. We observed that both alpha and beta diversity metrics have a strong negative relationship, showing a clear spatial pattern. Among the environmental drivers, geomorphological and climatic variables were the most influent, pointing out the importance of landscape heterogeneity and local oceanic climate conditions to favor endemic richness. We also found that historical factors (i.e. Last Glacial Maximum) significantly affected the pattern of endemic diversity. Interestingly, most of the variables showed contrasting effects on alpha and beta diversity. Our study proposes an approach for the identification of local hotspots of endemic species, which take into account both the spatially structured nature of ecological data and their associated environmental drivers. Our findings might provide new insights in the ecological process driving current endemic plant patterns and become pivotal for nature conservationist both to identify areas of high conservation value and to suggest appropriate management schemes also beyond existing protected areas.