Climate change and nutrient fluctuations interact to affect ecological networks in lakes

Abstract Climate change interacts with local processes to threaten biodiversity by disrupting the complex network of ecological interactions, wherein variation in network links drastically affects ecosystems (e.g., species loss). However, how ecological networks respond to climate change is largely unknown. We herein consider 24–43 years of monthly data from plankton communities in five peri-alpine Swiss lakes subject to warming and re-oligotrophication. Using empirical dynamic modeling, we show that the number and strength of causal taxa interactions respond nonlinearly, yet predictably, to water temperature and phosphorus. Warming reduces the connectance of ecological networks, particularly under high phosphate levels. This network reorganization shifts trophic control of food webs, leading to consumers being controlled by resources—signaling stability loss. By exposing the outcomes of complex interactions between warming, nutrient supply and plankton ecology, our results provide tools for studying and advancing our understanding of how climate change impacts the fabric of biodiversity.