Facilitation between plants shapes pollination networks

Although it is known that plant–plant and plant–pollinator interactions can strongly influence biodiversity and its effects on ecosystem functioning, the details of how competition and facili-tation among plants scale up to mutualistic interactions with pollinators and thus affect pollina-tion networks are poorly understood. We introduce a simple experimental system in which we control local plant interactions, measure pollinator responses and characterize plant–pollinator networks. We find that facilitation among plants produces synergistic and antagonistic effects on the pollinator community affecting the architecture and robustness of plant–pollinator net-works. Our results provide evidence for bottom-up non-additive effects of plant interactions on pollination networks and have implications for the way we study and manage ecosystems.