Recent pollinator population declines threaten pollination services and greatly impact plant-pollinator coevolution. In the present article, we investigate how such evolutionary effects affect plant-pollinator coexistence. Using eco-evolutionary dynamics, we study the evolution of plant attractiveness in a simple pollinator-plant model, assuming an allocation trade-off between attractiveness (e.g. nectar production, flower shape, and size) and plant intrinsic growth rates. First, we investigated how attractiveness evolution changes species persistence, biomass production, and the intensity of the mutualism (as a proxy for pollination services). The shape of the allocation trade-off is key in determining the outcome of the eco-evolutionary dynamics. Only concave trade-offs allow convergence to stable plant-pollinator coexistence. Then we analyze the effect of pollinator population declines on the eco-evolutionary dynamics. Decreasing intrinsic growth rates of pollinator population results in a plant-evolution-driven disappearance of the mutualistic interaction, eventually leading to pollinator extinction. With asymmetric mutualism favoring the pollinator, the evolutionary disappearance of the mutualistic interaction is delayed. Our results suggest that evolution may account for the current collapse of pollination systems and that restoration attempts should be enforced early enough to prevent potential negative effects driven by plant evolution.
