Collaborative Research: Hydrologic Connectivity and Water Storage as Drivers of Carbon Export and Emissions from Wetland-Dominated Catchments

在世界范围内，丰富的森林湿地已经通过挖沟和排水转变为农田。这些湿地对区域水和碳循环很重要。它们通过储水减少下游洪水，为下游生态系统提供溶解的有机碳，并有助于碳储存。虽然人们正在努力恢复干涸的湿地，但生态系统服务的恢复却滞后。目前迫切需要研究水文如何影响湿地生态系统服务的提供，以指导未来的恢复和管理。该项目将研究湿地丰富的德尔马瓦湾的水运动和碳循环。研究将集中在通常与邻近河流隔离的淡水湿地上。这些小湿地很容易受到土地利用变化的影响，它们对区域水和碳循环的影响也知之甚少。这项研究将为管理提供信息，有助于满足国家研究重点，并建设科学劳动力的能力。学生将参与研究的各个方面，以及与管理人员的互动会议和关于可操作科学的培训讲习班。该项目还将提供有关碳预算的数据，并推进下一代模型来估计碳动态。本研究将验证一个假设，即水储存能力（WSC），或单个或一组湿地可以储存的水量，是湿地和流域尺度水文、碳排放和下游碳出口的主要驱动因素。本项目将采用实证和模型相结合的方法，量化：(1)湿地和集水区尺度上的WSC及其在水位、停留时间和水量上的变化；(2)湿地（DOC浓度和组成、CH4和CO2排放）和流域尺度（DOC输出和组成、CH4和CO2输出）对碳动态的影响。相关的水文和生物地球化学数据将在六个不同WSC的研究集水区的18个湿地中收集，并在每个集水区的一个湿地中进行更密集的数据收集（例如，原位，高时间分辨率）。在集水区尺度上，将监测每个集水区出口的水排放、碳组成和出口的时间序列。导出的经验关系和校准的基于过程的水文模型将促进对湿地碳排放以及DOC、CO2和CH4从上游湿地向集水口的分流的预测理解。需要将WSC和相关的水文控制与碳生物地球化学联系起来的预期结果，为恢复实践和全球碳模型提供信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Worldwide, rich forested wetlands have been converted to agriculture through ditching and draining. These wetlands are important for regional water and carbon cycles. They reduce downstream flooding through water storage, providing dissolved organic carbon to downstream ecosystems, and contributing to carbon storage. While efforts are being made to restore drained wetlands, recovery of ecosystem services has lagged. Research is urgently needed to understand how hydrology influences delivery of wetland ecosystem services to guide future restoration and management. This project will investigate water movement and carbon cycling in wetland-rich Delmarva Bay. Research will focus on freshwater wetlands that are often isolated from adjacent rivers. These small wetlands are vulnerable to land-use change, and their impact on regional water and carbon cycling is poorly understood. This research will inform management, contribute to meeting national research priorities, and build capacity in the scientific workforce. Students will be engaged in all aspects of the research, as well as in interactive meetings with managers and training workshops on actionable science. This project will also provide data on carbon budgets and in advancing next-generation models to estimate carbon dynamics. This research will test the hypothesis that water storage capacity (WSC), or the amount of water a single wetland or group of wetlands can store, is a principal driver of wetland- and catchment-scale hydrology, carbon emissions, and downstream carbon export. Using coupled empirical and modeling components, this project will quantify: (1) WSC at wetland and catchment scales and resulting variation in water levels, residence time, and water export; and (2) consequent influences to carbon dynamics at both wetland (DOC concentration and composition, CH4 and CO2 emissions) and catchment scales (DOC export and composition, CH4 and CO2 export). Linked hydrologic and biogeochemical data will be collected in 18 wetlands across six study catchments that vary in WSC, with more intensive data collection (e.g., in situ, high temporal resolution) within one wetland per catchment. At the catchment scale, each catchment outlet will be monitored for time series of water discharge and carbon composition and export. Derived empirical relationships and calibrated process-based hydrologic models will advance predictive understanding of wetland carbon emissions and the shunting of DOC, CO2, and CH4 from upstream wetlands to catchment outlets. Expected outcomes linking WSC and associated hydrologic controls on carbon biogeochemistry are required to inform restoration practice and global carbon models.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.