Biodiversity is declining globally at an unprecedented rate, with islands —hosting c. 30% of biodiversity hotspots— being particularly vulnerable. Island species account for 80% of reported extinctions, yet much of their unique biodiversity, including intricate species interactions, remains unknown. It is urgent to document these interactions and predict the effects of their loss to mitigate further declines. Detecting ecological interactions is a major challenge, but emerging theories and tools like critical transition theory and complex network analysis offer hope. As relatively simple systems with clear boundaries, islands present a unique opportunity to deepen our understanding of ecological complexity.
IslandLife will provide the most comprehensive and quantitatively sophisticated study of multilayer networks to date in any terrestrial ecosystem. We are focusing on six archipelagos encompassing five oceans and a wide latitudinal gradient, comparing for the first time the food web structure of ‘pristine’ (little-disturbed) islands (of a few km2) with areas of similar size in nearby disturbed (human-inhabited) islands. The overarching goal is to unveil the unique biodiversity of these ecosystems, understand their complexity, and evaluate their fragility to global change drivers, such as biological invasions. The specific objectives are four: (1) To assess and compare the ecological complexity of pristine and disturbed islands, (2) To identify commonalities in the structure of multilayer networks across archipelagos located at different latitudes, spanning from the tropics to the Arctic and Antarctic zones, (3) To evaluate the effect of alien invasive species on the structure of multilayer networks and their role as potential drivers of ecosystem collapse, and (4) To test our ability to predict network reassembly during ecosystem restoration.
We are combining direct observations during intense fieldwork, automated video monitoring and deep-learning, cutting-edge molecular techniques, and newly developed coextinction models to predict persistence and resilience of island biota to disturbances. The project will represent a major breakthrough towards understanding the effects of global change on these valuable ecosystems, of great relevance to both theoretical ecologists and applied conservationists.
