Pollinators facilitate plant diversification and ecosystem productivity by exchanging reproductive services for food in the form of floral rewards. Pollinators also act as herbivores of non-floral vegetation, hosts for parasites, and prey for predators. However, synthetic understanding of ecological systems is inhibited by the segregation between studies of pollination networks and food webs. Such understanding has become increasingly important as anthropogenic disturbances gravely threaten the persistence of pollination systems along with their evolutionary function and service provision including agro-ecosystem services. We address these problems by integrating theories of plant-pollinator and feeding interactions to better understand effects of mutualisms on ecological stability, ecosystem services, evolutionary diversification, and species’ abundance and productivity. Based on our integrated theory, we developed a mechanistic model of nonlinear consumer-resource dynamics within complex ecological networks. Our empirically informed multiplex networks of pollination and food-web interactions help elucidate how pollination mutualisms affect the stability and dynamical behavior of complex ecological systems.
Results/Conclusions
We found that pollination is broadly destabilizing due to the dynamics of extinction cascades triggered by pollinator extinction. The extent of these extinction cascades is mitigated when pollinators can consume trophic resources beyond floral rewards. Interestingly, there is an outlying group of networks in which mutualistic interactions stabilize multiplex networks and also cause stability to increase with complexity. These outliers avoid extinction cascades and support a more diverse community of low trophic-level consumers than networks of the same structure restricted to traditional food web dynamics. Finally, we found that the mean availability of floral rewards at the end of our simulations tightly corresponds to our systems’ dynamical behavior and species composition. This suggests that the abundance of floral rewards may help predict the conditions under which pollination mutualisms may facilitate ecosystem stability and diversity.