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

许多研究表明，生物多样性影响生态系统的稳定性和功能，但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。 本研究将探讨增加植物多样性如何影响河岸生态系统功能的恢复，从地表水和地下水中去除氮：氮在植物生物量和反硝化中的保留。 在这项研究中，多样性将使用植物性状（例如相对生长速率，比叶面积）来测量，以计算一个创新的，多变量的功能多样性（FD）的措施，使用生态距离和聚类。 将在100块田间地块上种植1、4或8个物种的组合。 然而，多物种小区的多样性将计算为物种的FD之和。 反硝化作用将在全年进行多次测量，植物生物量将在未来两年的每个生长季节结束时收获。这项研究将评估功能多样性的重要性，以重建恢复湿地的关键生态系统生态地球化学功能。更广泛的影响：这项拟议中的研究结果将提供新的见解，可用于加强未来的河岸恢复工作，以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，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，如入侵物种的预防或微生物多样性的发展。

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.