CAREER: Nitrogen Sources, Pathways, and Fluxes in Chesapeake Bay Watershed Wetlands

职业：切萨皮克湾流域湿地的氮源、途径和通量

• 批准号: 2239715
• 负责人: Kimberly Van Meter
• 金额: $ 64.46万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-15 至 2028-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2239715&HistoricalAwards=false
• 关键词: CAREER; Nitrogen; Sources; Pathways; Fluxes

The water quality of rivers, lakes, and coastal regions across the U.S. is at risk due to growing urban populations, large-scale use of commercial fertilizers, and runoff from high-density livestock production. Within the Chesapeake Bay Watershed, watershed managers and landowners continue to struggle with reducing nutrient runoff, despite decades of initiatives to improve the health of the Bay. In recent years, as stakeholders have worked to implement better watershed management practices, there has been increased interest in wetland restoration as a tool to improve water quality, while also providing aquatic habitat and increasing biodiversity. Unfortunately, our understanding of how to optimize the placement and function of restored wetlands to improve water quality remains limited. In this project, the investigator will use a combination of intensive wetland monitoring and large-scale data analysis to better understand how to reduce agricultural nutrient runoff to downstream waterways under changing climate and land-use conditions. The project also has an outreach component that will involve development of a pilot Chesapeake Summer Water Institute program. The program will bring graduate student researchers together with Chesapeake Bay-focused agency staff and other stakeholders to facilitate exchange of information, the development of ‘problem-focused’ research teams, and the use of process-based and data-driven modeling approaches to answer questions regarding improvement of Chesapeake Bay water quality.The primary objective of the proposed research is to better understand controls on fluxes of landscape nitrogen (N) to current and restorable wetland sites and, thus, to better predict the contributions of wetlands to water quality in the Chesapeake Bay Watershed. To meet this objective, the PI will use MESA–a metabolite of the widely used herbicide metolachlor–as a novel tracer of agricultural nitrate to identify the extent to which wetlands across a range of land-use types and positions intersect N flux pathways, and to quantify the resulting magnitudes of wetland N removal. The PI will leverage hundreds of existing water-quality samples from the National Wetland Condition Assessment together with more intensive monitoring of MESA at individual wetland sites to better our understanding of the spatially varying connectivity of wetlands with both groundwater N fluxes, and thus to refine estimates of wetland N removal magnitudes and associated N2O fluxes. In addition, analysis of MESA chirality will be used to estimate fluxes of legacy N to existing wetlands, thus bettering our understanding of the contribution of legacy N to current water quality.This award is co-funded by the Division of Earth Science's Hydrologic Sciences program and the Division of Environmental Biology's Ecosystems Sciences program.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.

由于城市人口的增长、商业化肥的大规模使用以及高密度畜牧业生产的径流，美国河流、湖泊和沿海地区的水质面临风险。在切萨皮克湾流域内，流域管理者和土地所有者继续努力减少营养径流，尽管几十年来的倡议，以改善海湾的健康。近年来，随着利益攸关方努力实施更好的流域管理做法，人们对湿地恢复越来越感兴趣，将其作为改善水质的工具，同时提供水生生境和增加生物多样性。不幸的是，我们对如何优化恢复湿地的位置和功能以改善水质的理解仍然有限。在这个项目中，研究人员将使用密集的湿地监测和大规模数据分析相结合，以更好地了解如何在不断变化的气候和土地利用条件下减少农业营养径流到下游水道。该项目还有一个推广部分，将涉及制定一个试点切萨皮克夏季水研究所方案。该计划将把研究生研究人员与切萨皮克湾为重点的机构工作人员和其他利益相关者聚集在一起，以促进信息交流，发展“以问题为重点”的研究团队，以及使用基于过程和数据驱动的建模方法来回答有关改善切萨皮克湾水质的问题。拟议研究的主要目标是更好地了解景观氮通量的控制（N），目前和可再生的湿地网站，从而更好地预测湿地的贡献，水质在切萨皮克湾流域。为了实现这一目标，PI将使用MESA-广泛使用的除草剂异丙甲草胺的代谢产物-作为农业硝酸盐的新型示踪剂，以确定在何种程度上湿地在一系列土地利用类型和位置相交的N通量途径，并量化湿地N去除的幅度。PI将利用国家湿地状况评估中的数百个现有水质样本，以及对各个湿地站点的梅萨进行更深入的监测，以更好地了解湿地与地下水氮通量之间空间变化的连通性，从而改进湿地氮去除量和相关N2 O通量的估计。此外，梅萨手性的分析将被用来估计通量的遗留N到现有的湿地，从而更好地了解遗留氮对当前水质的贡献。该奖项是共同的-该奖项由地球科学部的水文科学计划和环境生物学部的生态系统科学计划资助。该奖项反映了NSF的法定使命，并通过评估被认为值得支持使用基金会的知识价值和更广泛的影响审查标准。