Dissertation Research: Shared pollinators affect flowering plant coexistence

Cornell University, Ithaca NY

Investigators

Abstract

Without pollinators like bees, bats and butterflies, most of the world's flowering plants would disappear. Because of the importance of pollinators, insuring their health is essential for preserving biodiversity and promoting global agricultural security. As pollinators, some native bees can show strong loyalty by limiting their visits to only flowers from a certain species, while other bees may not be so loyal, visiting many different types of flowers. In theory, plants with loyal pollinators should produce more fruit and seeds because the pollinators provide only the appropriate pollen type when they visit. The aim of this research is to understand the degree to which native bees show loyalty to certain plants. This study also explores how the sharing of pollinators between closely related plants might influence how many seeds those plants produce. If some of the plants do worse than others when sharing pollinators, differences in pollinator loyalty may influence how common or rare those plants become. The results of this research are important for understanding the role pollinators play in maintaining healthy and diverse agricultural and natural plant communities. This research contributes to the training of a graduate student, develops a lab and field program for a high school biology class and provides opportunities to engage and encourage women and under-represented students in STEM science. Coexistence theory addresses how species richness is maintained in biological communities by framing species interactions as a balance of competition within versus between species. This study uses that theory to investigate whether pollinator sharing affects coexistence dynamics in four co-occurring plants in the genus Clarkia. Determining whether pollinator sharing is detrimental or favorable for flowering plant coexistence hinges on understanding the flower preference and constancy of native bees that specialize on flowers and the quantity of pollen they provide. The diversity and quantity of pollen found on Clarkia's pollinators will be measured with a genetic identification technique (qPCR). These measurements will be used in conjunction with estimates of each plant species' competitive ability to determine whether shared pollinators can change plant fitness and whether the pattern shows a negative frequency dependence. This study will shed light on the role that pollinator sharing can play in promoting the coexistence of flowering plants.