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.

由于城市人口的增加，商业肥料的大规模使用以及高密度牲畜生产的径流，美国河流，湖泊和沿海地区的水质处于危险之中。在切萨皮克湾流域内，分水岭的经理和土地所有者继续为减少营养径流而挣扎，造成数十年的倡议以改善海湾的健康状况。近年来，随着利益相关者努力实施更好的流域管理实践，人们对湿地恢复的兴趣增加了，作为提高水质的工具，同时还提供了水生栖息地和增加生物多样性。不幸的是，我们对如何优化恢复的湿地的放置和功能以提高水质的理解仍然有限。在该项目中，研究人员将使用密集的湿地监测和大规模数据分析的结合，以更好地了解如何在不断变化的气候和土地利用条件下将农业营养径流减少到下游水道。该项目还具有宣传部分，其中涉及开发Chesapeake夏季水研究所计划。该计划将把研究生研究人员与Chesapeake湾的机构工作人员和其他利益相关者一起，以促进信息的交换，发展“以问题为中心”的研究团队的发展以及使用基于过程和数据驱动的建模方法来回答有关Chesapeake Bay水质的改进的问题，以改善诉讼的研究。地点，因此可以更好地预测湿地对切萨皮克湾流域中水质的贡献。为了满足这一目标，PI将使用台面（一种广泛使用的除草剂元甲甲的代谢物），这是一种新型农业硝酸盐的示踪剂，以确定一系列土地利用类型和位置相交的湿地在多大程度上，以在多大程度上相交的N频道，并量化了湿地量的湿地量。 PI将利用来自国家湿地条件评估的数百种现有水质样本，以及对单个湿地站点对台面的更密集监测，以更好地了解我们对湿地的空间变化连通性的理解，从而对两种地下水N磁带的湿地进行了变化，从而对湿地n2O的湿地量和相关的N2O通量进行了改进。此外，对MESA手学的分析将用于估算现有湿地的传统n的通量，从而提高了我们对遗产n对当前水质的贡献的理解。该奖项是由地球科学的水文科学计划共同资助的基金会的智力优点和更广泛的影响评论标准。