Background/Question/Methods Ecological theory predicts that species interactions embedded in multitrophic networks shape the opportunities for species to persist. However, the lack of observational or experimental support of this prediction has limited our understanding of how species interactions occurring within and across trophic levels simultaneously regulate the maintenance of biodiversity. Here, we integrate a mathematical approach and detailed observations and experiments in plant-pollinator communities to demonstrate the need to jointly account for species interactions within and across trophic levels when estimating the ability of species to persist.
Results/Conclusions First, we show that community feasibility domains, a theoretically-informed measure of coexistence probability, are indeed reflecting moderately well the empirical plant-pollinator networks stability in 16 study sites over seven years, bridging the gap between theoretical and empirical expectations. Next, we show using cage experiments that the persistence probability of plant species increases when introducing the effects of plant-pollinator interactions. However, across trophic levels, we show that the persistence probabilities of both plants and pollinators exhibit idiosyncratic changes when experimentally manipulating the multitrophic structure. Finally, using empirical data on communities comprising more than 50 species for three trophic guilds (plants, pollinators, and herbivores), we show that empirical estimations of the feasibility domains were higher with respect to random network structures, suggesting that observed interaction structures tend to maximize coexistence within its imposed limits. Interestingly, we show that higher network connectance leads to lower coexistence opportunities. Our work provides tractable observational, experimental, and theoretical platforms upon which it is possible to investigate the multitrophic factors affecting species persistence in ecological communities.
