Linking Migration Flows With the Prevalence of Exotic Plant Species in the Andes

Human mobility and connectivity between cities are key features of globalization that foster urban expansion, landscape transformations, and changes in species distributions. Andean ecosystems, which function as biodiversity reservoirs, are vulnerable to environmental changes and to the introduction of exotic species. Through this study, we assess the association of migratory flows and other socioenvironmental characteristics with the prevalence of exotic woody species in the Andean region. We collected data on urban and demographic dynamics, migration proxies, and topographic and climate indicators for every first-order administrative unit of the Andean region. We used global biodiversity databases to obtain occurrence records of woody plants and estimated the proportion of exotic species records in each administrative unit. We performed multiple regression models that assessed the association of this prevalence with socioenvironmental information, and we compared them using the Akaike information criterion. We obtained 2,461,168 records of native species and 891,579 records of exotic species. Topography, climate, and immigration were included in the 10 best models, suggesting that the social connectivity of administrative units (through immigration) is a driver of changes in species composition of local communities. We consider that the prevalence of exotic species in woody plant composition is highly influenced by cultural drivers through the introduction of exotic species and through their use in urban and periurban environments.