Dissertation Research: The Role of Plant Functional Diversity in Regulating Nitrogen Removal in Restored Riparian Wetlands

大量研究表明，生物多样性影响生态系统的稳定性和功能；然而，植物多样性在湿地生态系统中的功能作用在很大程度上是未知的。这项研究将调查植物多样性的增加如何影响河岸生态系统功能的恢复，这些功能可以从地表水和地下水中去除氮：植物生物量中的氮保留和反硝化作用。在这项研究中，多样性将使用植物特性(例如，相对生长率、比叶面积)来衡量，从而使用生态距离和聚类法来计算创新的、多变量的功能多样性(FD)。100块田地将种植1、4或8个树种的组合。然而，多物种样地的多样性将以物种的FDs之和来计算。全年将对反硝化作用进行多次测量，并在未来两年的每个生长季结束时收获植物生物量。这项研究将评估功能多样性对在恢复的湿地中重建关键的生态系统生物地球化学功能的重要性。广泛的影响：这项拟议的研究结果将提供新的见解，可用于加强未来的河岸恢复努力，改善水质和防止富营养化。研究人员还将促进与其他科学家的合作努力，以解决同样重要的问题，包括功能多样性对其他生态系统功能的影响，如入侵物种预防或微生物多样性开发。

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.