Collaborative Research: How do hydrology and biogeochemistry control carbon flux from headwater streams to the atmosphere?

合作研究：水文学和生物地球化学如何控制从水源流到大气的碳通量？

• 批准号: 1417592
• 负责人: Daniele Tonina
• 金额: $ 9.41万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417592&HistoricalAwards=false
• 关键词: Collaborative; Research; How; do; hydrology

It is known that streams collect, process, and release much of a basin's water. It is less known that streams also collect, process, and release much of a basin's carbon. Carbon is collected by streams in various forms, some of that carbon is processed by microbes in the streambed into carbon dioxide (CO2), and much of that CO2 is vented to the atmosphere during downstream flow. These processes are particularly important in small, headwater streams. Since headwater basins drain significant land surface, these coupled water-carbon processes may be globally significant. This project will measure, model, and understand this coupled water-carbon cycle via intensive study of the stream carbon cycle within one headwater stream draining a 96-hectare basin in western Oregon. By using the Watershed 1 of the HJ Andrews Experimental Forest, this study will leverage a history of detailed data collection and a large number of existing measurements. The project team will partner with the Audubon Society to teach 1000 school children stream hydrology and ecology in the field.This project has two main goals. The first is to develop an integrated modeling framework to simulate carbon cycling in streams that is widely transferable to model subsurface and surface processes of streams in earth system models. The second is to test and present an integrated theory of stream and groundwater hydrology, carbon biogeochemistry, and CO2 production and efflux in a stream. These goals will be accomplished by developing an integrated carbon model for headwater streams that simulates hydrologic processes (e.g., transport, hyporheic exchange) and biogeochemical processes (e.g., transformation between particulate and dissolved organic carbon, aerobic respiration rates of these carbon "pools"). Modeling will be coupled with direct measurements of groundwater delivery of soil-respired CO2, biological and physical processes controlling carbon cycling, measurements of dissolved oxygen, hydrology, and CO2 efflux from the stream to subcanopy respiration measured at a flux tower above the stream. In situ hyporheic mesocosms will be used to manipulate and monitor reactive transport along flow paths to parameterize biogeochemical rate expressions for use in the integrated model. Finally, the project will upscale the reach-scale processes to watershed scale to explain carbon fluxes from river networks.

众所周知，溪流收集，处理和释放大部分盆地水。鲜为人知的是，流还收集，处理和释放盆地的大部分碳。碳是通过各种形式的流收集的，其中一些碳是由流床中的微生物加工成二氧化碳（CO2）的，并且在下游流动期间，大部分二氧化碳被排放到大气中。 这些过程在小型源水流中尤为重要。 由于源头盆地会排出大量的土地表面，因此这些耦合的水碳过程可能具有全球意义。 该项目将通过对俄勒冈州西部96公顷盆地的一条源水流中的河流循环进行深入研究，测量，建模和理解这种耦合的水碳循环。通过使用HJ Andrews实验森林的分水岭，这项研究将利用详细的数据收集和大量现有测量的历史。 项目团队将与奥杜邦协会合作，在该领域教授1000名学童流文学和生态。该项目有两个主要目标。首先是开发一个集成的建模框架，以模拟流中的碳循环，该流可以广泛传递到地球系统模型中流的模型地下和表面过程。第二个是在流中测试并提出综合的溪流和地下水水文学，碳生物地球化学以及二氧化碳的产生和外排的综合理论。这些目标将通过开发用于雷头流的集成碳模型来实现，该模型模拟水文过程（例如，运输，低音交换）和生物地球化学过程（例如，颗粒和溶解的有机碳，这些碳“池”的有氧呼吸速率之间的转化，这些碳“池”）。建模将与土壤验证的CO2的地下水递送，控制碳循环的生物和物理过程的直接测量，测量溶解的氧，水文学和CO2外排从溪流到亚阳期呼吸的二氧化碳呼吸，这些呼吸是在溪流上方的通量塔上测量的。原位低音中的中焦将用于操纵和监测沿流动路径的反应性传输，以参数化在集成模型中使用的生物地球化学速率表达式。最后，该项目将把覆盖范围的流程提高到分水岭，以解释河网络的碳通量。