Biogeographical network analysis of plant species distribution in the Mediterranean region

International audienceThe study of biotic taxa distribution on a territory represents a key step in theunderstanding, analysis and conservation of ecosystems, but often hindered by alevel of diversity and complexity that may appear overwhelming at first glance. Tobetter understand and visualize the biogeographical structure of a territory, it istherefore necessary to divide this territory into meaningful and coherentgeographical regions, minimizing the heterogeneity in taxonomic compositionwithin regions while maximizing the differences between them. While thedelineation of biogeographical regions has been based for a long time on expertknowledge of qualitative data collection, the increasing availability of species-leveldistribution data and the recent technological advances have allowed for thedevelopment of more rigorous frameworks. While limited consideration is given tonetwork approaches in biogeography, the generic nature of networks and the levelof complexity that they can capture at different scale, make it a powerful tool forinvesting the interactions among species occurring on a territory. In this work, weused a network approach to identify and characterize biogeographical regions insouthern France, based on a large database containing information on millions ofvegetation plant samples corresponding to more than 3,500 plant species