Species loss in key habitats accelerates regional food web disruption.

Understanding the robustness of ecological networks against sustained species losses is paramount to devising effective biodiversity conservation strategies. To explore the impacts of species losses on network robustness (the capacity of food webs to withstand primary extinctions), we used a trophic metaweb of 7808 vertebrates, invertebrates and plants and 281,023 interactions across Switzerland. We inferred twelve regional multi-habitat food webs and simulated non-random species extinction scenarios on these webs, focusing on broad habitat types and regional species abundances. Here, we show that targeted removal of species associated with specific habitat types, particularly wetlands, resulted in greater network fragmentation and accelerated network collapse compared to random species removals. Networks were more vulnerable to the initial loss of common rather than rare species. These findings underscore the critical need for integrated conservation strategies maintaining a diverse mosaic of habitats in a landscape to mitigate the cascading effects of species loss.