Abstract

not-yet-known not-yet-known not-yet-known unknown Early ecological theory predicts that complex ecological networks are unstable and are unlikely to persist, despite many empirical studies of such complexity in nature. This inconsistency has fascinated ecologists for decades. To resolve complexity-stability relationships, coupling population dynamics and trait dynamics is considered to be an important way to understand the long-term stability of ecological community assemblages. However, incorporating adaptive processes into ecologically realistic networks with both antagonistic and mutualistic interactions is still a challenge. Here, we explored an adaptive food-web model to evaluate how the evolution of foraging preference (behaviour trait) to determine the relationship between network complexity (e.g., connectance) and stability (e.g., community persistence) in a multiplex community with multiple interaction types (MEST: mutualist-exploiter-specialist predator-top predator). Our theoretical results showed: (i) adaptive foraging of the top predator contributes to the stability of mutualism and intermediate intensity of foraging adaptation can lead to chaotic dynamics in a four-species MEST community; (ii) the connectance-stability relationship may show positive monotonic, negative monotonic, peaked and double-peaked patterns in general MEST communities, while the double-peaked pattern is only obtained when both the adaptation intensity and interspecific competition are high. Moreover, we infer that foraging adaptation of the top predator may alter positive and/or negative feedback loops (trait-mediated indirect effects) to affect the stability of the MEST community. Finally, our theoretical predictions may be consistent with both the negative monotonic complexity-stability relationship revealed in freshwater communities and the peaked pattern revealed in marine communities. Our adaptive dynamics framework may provide an effective way to address the complexity-stability debate in real ecosystems.