Abstract ID: 3.13415 | Accepted as Talk | Talk/Oral | TBA | TBA

A mere 3% of the Earth’s land surface is covered by the alpine biome, yet its contribution to mountain biodiversity and ecosystem services is unparalleled. Alpine ecosystems are also very sensitive to global change and already experience rapid upslope migrations and species turnover. In this study, we aim to explore spatial and temporal turnover in plant communities of the Global Alpine at present and under future climate change scenarios. For 27 main alpine regions, we performed General Dissimilarity Models (GDMs) on 11.867 sPlot vegetation data and 69 topo-environmental factors. The models assessed mean species turnover rates and identified their main drivers in every alpine region. Finally, we used predictions of the previously selected factors according to four climate change scenarios, to project species turnover for 2030, 2040 and 2050. Overall, Oceanian and African regions had the smallest turnover rates, while Andean and Himalayan regions had the highest ones. These results highlight the importance of environmental heterogeneity along sharp altitudinal gradients on species turnover. Despite drivers varying chiefly between regions, we observed stronger representation of seasonality factors in temperate regions and productivity factors in (sub-)tropical ones. Moreover, future predictions confirmed the high sensitivity of tropical alpine regions to climate change. Our results shed new light on the spatial patterns and future temporal trends of plant turnover in the Global Alpine and provide useful evidence to anticipate climate change impacts in these unique regions.