Numerous studies have demonstrated that biodiversity affects the stability and function of ecosystems; yet the functional role of plant diversity in wetland ecosystems is largely unknown. This research will investigate how increasing plant diversity affects the restoration of riparian ecosystem functions that remove nitrogen from surface and ground water: nitrogen retention in plant biomass and denitrification. In this study, diversity will be measured using plant traits (e.g. Relative Growth Rate, Specific Leaf Area) to calculate an innovative, multivariate measure of Functional Diversity (FD) using ecological distance and clustering. One hundred field plots will be planted with combinations of 1, 4 or 8 species. However, the diversity of the multi-species plots will be calculated as the sum of the species' FDs. Denitrification will be measured several times throughout the year and plant biomass will be harvested at the end of each growing season over the next two years. This research will evaluate the importance of functional diversity to the re-establishment of key ecosystem biogeochemistry functions in restored wetlands.
Broader Impacts: The results of this proposed study will provide new insights that can be used to enhance future riparian restoration efforts, to improve water quality and to prevent eutrophication. The investigators will also promote collaborative efforts with other scientists to address equally important questions including functional diversity effects on other ecosystem functions, such as invasive species prevention or microbial diversity development.