Linking Hydrologic Exchange to Nitrogen Cycling at the Groundwater-Stream Water Interface

杰克曼、特里斯卡和达夫地下水和地表水之间的界面是一个动态的边界，在那里营养物质、溶解氧和氧化还原电位出现了强烈的梯度。这种被称为潜流带的界面带对溪流和河流的生物群落、从陆地到水生生态系统的营养物质的流动以及对溪流、河流和洪泛区的水文产生了相当大的影响。本项目的重点是这种动态界面，重点是氮的循环和对水生大型植物的影响。该项目结合了对潜流带水文学的深入研究，以及在这一界面的生物地球化学和生物相互作用。这项研究将在将陆地/水界面的集水区的水文和生物地球化学结合起来方面取得重大进展。已证明河岸带可提供缓冲能力，以减少向水生生态系统输入过多的陆源营养物质。然而，这些关于这一界面过滤能力的初步研究并没有与该区域内水文流动路径在空间和时间上的严格表征相结合。该项目量化了沿已知流动路径的氮循环的主要组成部分，并跟踪了这些过程对溪流和河流生态系统生物群的影响。

JACKMAN, TRISKA, and DUFF The interface between ground water and surface water is a dynamic boundary where strong gradients in nutrients, dissolved oxygen, and redox potential occur. This interface zone, termed the hyporheic zone, exerts considerable influence on the biotic communities of streams and rivers, the flux of nutrients from terrestrial to aquatic ecosystems, and upon the hydrology of streams, rivers, and floodplains. This project focuses upon this dynamic interface with emphases on the cycling of nitrogen and effects on aquatic macrophytes. The project combines a thorough study of hydrology of the hyporheic zone with the biogeochemistry and biological interactions at this interface. This research will yield significant progress in coupling the hydrology and biogeochemistry of catchments at the terrestrial/aquatic interface. Riparian zones have been shown to provide buffering capacity for reducing the import of excessive nutrients of terrestrial origin into aquatic ecosystems. These initial studies on this filtering capacity of this interface, however, have not been coupled to a rigorous characterization of the hydrologic flow paths in space and time within this zone. This project quantifies major components of nitrogen cycling along known flow paths and follows the impact of these processes to the biota of stream and river ecosystems.