Biodiversity is a critical element of community properties and ecosystem processes. Both plant species richness and genetic diversity positively affect processes ranging from primary production, ecosystem stability, and the maintenance of diversity. In nature, it is likely that species diversity and genetic diversity interactively affect how communities are structured and ecosystems function. However, the relative contribution of species diversity and genetic diversity to ecological processes is unknown, and potential interactions between the two levels of diversity have not been investigated. Here, I report results from a common garden experiment conducted in a coastal freshwater dune habitat at Sleeping Bear Dunes National Lakeshore in Empire, MI. I manipulated plant species diversity (0, 1, 3, or 6 species) and genetic diversity (0, 1, 3, or 6 populations) within a dominant, dune-building species (Ammophila breviligulata) to address how both levels of diversity simultaneously influence ecological processes

Results/Conclusions

Preliminary results suggest that plant species diversity and genetic diversity interactively mediate a wide range of ecological properties and processes, including decreased arthropod species richness, increased resistance to plant invasion, and increased primary productivity.