All organisms interact with other species in ways that impact their survival. In mutualist interactions, species 'barter' goods and services that they cannot provide for themselves. For example, as pollinators visit plants to gain vital energy and nutrients (nectar and pollen), they transfer pollen (and thus genes) between plants. However, variation in pollinator abundances and the availability of co-pollinators may change the benefits plants receive from partnerships with any one species. The goal of this project is to characterize how partner abundance impacts plants' reproductive success and population growth. Population density of one pollinator species will be manipulated, and effects will be compared for related plants that vary in numbers of co-pollinators.
Results from this study will elucidate how density dependence and partner specialization affect benefits from mutualist interactions. Understanding pollination mutualisms is of particular concern, since services provided by native pollinators influence the yield of economically vital crop plants and the diversity, persistence, and structure of native plant communities. Reported declines in some pollinator species groups worldwide imply further urgency. Focal genera in this study, Trifolium (clovers) and Bombus (bumblebees), have high economic and conservation value. Finally, this project includes a partnership with a local K-12 class and provides research opportunities for undergraduates.
