Format: ORAL

Borja Jimnez-Alfaro1, George P Malanson2, Josep Padulls Cubino3

1 Biodiversity Research Institute (CSIC-Univ.Oviedo-Princ.Asturias), Mieres, Spain 2 Department of Geographical and Sustainability Sciences, University of Iowa, Iowa City, United States 3 Autonomous University of Barcelona, Barcelona, Spain

Alpine floras contain unique biodiversity above the climatic treeline globally. Understanding such biodiversity needs to consider multiple facets from evolutionary history to the assembly of cold-adapted plant lineages in regional floras and local communities. Here, we summarize recent research on the patterns and drivers of species pools in 23 regional alpine floras of Central and Southern Europe. At the phylogenetic level, we found that climatic changes during the glacial-postglacial periods had an important role in determining current species pools, with closely related lineages in cold and unstable climates. At the taxonomic level, the diversity of European alpine pools is mainly influenced by regional isolation and dispersal limitation. Environmental and topographic heterogeneity complement area effects to explain regional richness, but the area becomes especially critical to maintain species richness in the smallest regions. The taxonomic dissimilarity among regions reflects past glacial connections, but present European alpine floras are strongly isolated, and they are expected to respond differently to regional climatic variation. All these results suggest regional idiosyncrasies in the response of alpine diversity to climate change, concerning spatial, bedrock, and topographic configurations. Since the assembly of European alpine floras may not be in equilibrium with climate, the effects of current warming must be evaluated at meso- and micro-scales within a given species pool, with expected discrepancies among regions. Accounting for multiple regional studies with similar approaches in different regions, especially those supporting relict alpine communities, will be necessary to anticipate future changes in alpine plant diversity.