Response diversity is a major driver of temporal stability in complex food webs

Global change constitutes a major threat to biodiversity and ecosystem functions and places the temporal stability of ecological communities at risk. Classic theory identifies species richness and food web structure as key drivers of temporal stability, while recent work highlights response diversity—variation in species’ responses to environmental perturbations—as a critical stabilizer via asynchrony in population fluctuations. However, how these mechanisms interact in complex, multi-trophic communities remain unresolved. Using a stochastic, bioenergetic food web model, we integrate these multiple bodies of theory to reveal that response diversity is a major driver of community stability. Moreover, our integrated theory reveals that positive stability-richness relationships emerge only in the presence of response diversity. In contrast to previous work, we also find that food web structure is only a secondary driver of community stability but interacts with response diversity to determine the sign of the stability-richness relationship. Our study reveals identifiable pathways by which food web structure and response diversity drive community stability and raises concerns about how the loss of response diversity may lead to a breakdown of community stability.