Biotic and Abiotic Drivers of Plant-Pollinator Interaction Rewiring

Abstract

In this dissertation, I examine variation in plant-pollinator interaction patterns. I present two observational studies exploring drivers of interaction variation, followed by an experiment in which I demonstrate the effect of changing plant-pollinator interactions. First, I use a structural equation modeling framework to demonstrate that temperature variation and plant community dissimilarity directly drive variation in plant-pollinator interaction patterns. Both variables also provide pathways for geographic distance to indirectly impact rewiring. Second, I use a multinomial logistic regression to show that pollinators prefer different flowers at different temperatures, even within a constant plant community. Third, I present an experimental manipulation that connects the removal of the most abundant bumble bee in a community to the production of fertilized seeds in a focal plant. In this experiment, I find that the composition of the plant and pollinator communities as well as the distribution of morphological traits both guilds influences the way in which pollinator removal influences pollination function. As a whole, this dissertation demonstrates that interspecific interactions cannot be considered static components of plant-pollinator communities. Rather, ecologists must consider how changes to biotic and abiotic conditions are likely to affect not only the organisms present in a community but also the interactions between them.