Eco-evolutionary dynamics of plant-insect communities facing disturbances: implications for community maintenance and agricultural management
Résumé
Understanding the response of natural communities to current global changes is crucial for the conservation and management of ecosystems. While the ecological and evolutionary responses of antagonistic or mutualistic systems have been studied separately, few studies investigate the eco-evolutionary response of systems combining different interaction types. We build an evolutionary model of a plant-pollinator-herbivore community, where both pollinators and herbivores are confronted with the same external disturbance, insecticide use. Pollinators' and herbivores' response to disturbances is controlled by a trait (e.g. sensitivity trait) that incurs a cost in reproduction. Using Adaptive Dynamics Theory, we find that herbivore evolution lowers densities of species and may drive pollinators to extinction while pollinator evolution increases densities and enhances community maintenance. We then show that coevolution, by constraining the variability of coevolving species, produces qualitative dynamics that cannot be predicted from the mere addition of single-species evolution scenarios.