Effects of Resource Availability and Community Composition on the Outcome of Multiple Species Interactions with Ipomopsis Aggregata

Rocky Mountain Biological Laboratory, Crested Butte CO

Investigators

Abstract

0089643 Irwin Ecologists and evolutionary biologists are fundamentally interested in the ways in which organisms interact to shape their abundance and design. Although the complexity of interactions within a community has long been recognized, our understanding of how a multitude of organisms ultimately shape the ecology of plant communities and the evolution of floral traits is still in its infancy. Pollination biologists have demonstrated the importance of pollinators in governing floral design, while recognizing that antagonistic organisms also play a role in the ecology and evolution of flowering traits. However, the effects of antagonists, such as herbivores, nectar robbers, and seed predators, on plant-pollinator mutualisms have often been considered in isolation. To fully understand the interplay and outcome of multiple species with their host plants, we must account for the complexity of interspecific interactions, and do so across communities that differ in resource availability and plant composition. The integration of simultaneous direct and indirect selection pressures from abiotic and abiotic factors will ultimately shape plant reproduction and plant traits over ecological, microevolutionary, and macroevolutionary scales. The aim of this research is to understand the simultaneous importance of interactions among several antagonists with their host plants and mutualist pollinators, and how resource availability and community composition affect the outcome of such interactions. Experiments will examine the combined effects of a nectar-robbing bumblebee, a pre-dispersal seed predator, an ungulate herbivore, and plant community composition on the reproductive success of the subalpine plant, Ipomopsis aggregata. This work is novel in integrating the effects of multiple antagonists on the outcome of plant-pollinator mutualisms under different environmental conditions. Understanding the complexity of plant-pollinator-antagonist interactions will provide a deeper knowledge of how species are ecologically and evolutionarily linked in biological communities.