Ecosystem functional meltdown through biological annihilation in the world’s ecoregions

• Ecosystem function depends on species diversity; effects of species loss on functionality remain unclear. • Over 65% of functional diversity in Asia, Europe, and America comes from threatened species. • Ecosystems with species at high risk are highly vulnerable to ecological meltdown. • Ecological meltdown collapse could drastically affect human lifestyles and global environmental systems. Ecosystem resilience and functioning depends largely on species’ diversity and ecological roles. Functional diversity (FD) is a measure of the diversity of roles within ecosystems. The massive population and species extinction crisis, namely biological annihilation, is occurring around the World. Here we assessed the influence of mammals at risk, according to IUCN, on FD (trait richness) across ecoregions globally. Overall global models showed significant influence of mammals at risk over FD, and this influence was greater at regional scale. At least 65% of total FD was explained by threatened species in selected ecoregions in Asia, Europe, America and to a lesser extent in others. Since the ecoregion FD is disproportionally influenced by species at risk of disappearing in the short term, ecosystems supporting those species are more vulnerable to ecological meltdown through loss of its functional and resilience capacity; implications for humanity are unprecedented and ecological meltdown will undoubtedly impact to the globe.