Uncovering the mechanisms driving co-flowering community assembly: integrating flowering and floral trait distribution patterns via a novel use of network analysis

East Tennessee State University, Johnson City TN

Investigators

Abstract

To predict how environmental change will impact the long-term stability and species composition of plant communities it is critical to understand the ecological processes that determine community membership. This research will evaluate the combined importance of two ecological processes operating simultaneously in multi-species communities. First, competition between plant species for pollinators may result in the loss of the inferior competitor. Second, facilitation may cause both species to receive more pollinator visits and result in species co-occurrence. By measuring pollinator visits and flower traits attractive to pollinators the researchers will quantify the simultaneous action of competition and facilitation. These data will allow the researchers to better understand patterns of species coexistence and community composition. This research will also advance the science education of under-represented groups and first-generation college students in the Appalachian region. In addition, outreach activities associated with pollinator gardens at nature centers will increase awareness of pollination as a key ecosystem service. The project will use network analysis to identify co-flowering and floral-trait modules within serpentine seep communities in California. Observed modularity will be used to predict the roles of competitive and facilitative pollinator interactions as drivers of species assembly. The researchers propose that the distribution of flowering phenology and floral traits in a community are determined by: 1) the strength and direction of plant-plant interactions via pollinator visitation, and 2) the fitness cost of direct plant-plant interactions via interspecies pollen transfer. These predictions will be experimentally tested in the field by manipulating co-flowering community composition and in the greenhouse via hand pollination experiments with pure and mixed-pollen loads. The researchers make two predictions. First, species membership in different co-flowering modules is the result of competitive plant-plant interactions via pollinators. Second, species membership in the same co-flowering module can result from facilitative, competitive, or both types of interactions acting simultaneously. This research will help take our understanding of co-flowering community assembly from a descriptive to a more predictive stage. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.