Thesis defense – Avril WEINBACH – “Eco-evolutionary dynamics in different environments: implication for the maintenance and structure of ecological communities”

Environmental changes affect species but also the interaction connecting them within a community. Their ecological and evolutionary responses partly depend on biological traits affecting the type and strength of these interactions. In this thesis we use models to explore the impact of different environments on resource-consumer communities, either antagonistic (e.g. food webs) or mutualistic (e.g. plant-pollinator webs). We follow the impact of environmental parameters like temperature, abundance, and temporal distribution of interactors on their partner species. We study potential eco-evolutionary feedbacks, following the evolution of traits affecting the interaction like body size, investment in mutualism, or foraging time. Antagonistic interactions seem more stable than mutualistic ones via negative eco-evolutionary feedbacks. The more specialist species are also more fragile, often declining or being less able to evolve with environmental changes. Under specific modelling conditions we observe evolutionary responses previously reported in the literature e.g. decreased body size with warming, disinvestment in the mutualistic interaction when the partner population declines. Explicit modelling of the length and amplitude of the considered environmental perturbations could help explore the stability of the studied communities