Nitrogen Movement from Uplands to Streams in Forested and Deforested Tropical Watersheds

亚马逊河流域热带森林的砍伐改变了从陆地流入小溪的沉积物和营养物质的数量和形式。这些变化可能会改变溪流中的植物和动物群落，并可能最终影响较大河流的水质，包括亚马逊河本身。这项研究将量化在不同水文路径中从陆地流入水中的水量，包括地表径流、浅层地下径流和深层地下水流。它还将使用氮的稳定同位素氮-15来追踪有多少氮从陆地转移到水中，并量化氮在这些不同流动路径中的转化。这项工作将为氮在热带流域的移动提供新的基本信息。它将有助于改善牧场管理，设计河流边缘植被缓冲区，并保持亚马逊流域河流的水质。

The clearing of tropical forest in the Amazon Basin changes the amount and forms of sediment and nutrients that move from land into small streams. These changes can alter the plant and animal communities in streams and may ultimately influence water quality in larger rivers, including the Amazon River itself. This research will quantify the amount of water that moves from land to water in different hydrological pathways, including overland flows, shallow subsurface flows and deep groundwater flows. It will also use nitrogen-15, a stable isotope of nitrogen, to trace how much nitrogen moves from land to water and to quantify how nitrogen is transformed within these different flow pathways. This work will provide new basic information on how nitrogen moves in tropical watersheds. It will help to improve pasture management, to design stream-edge vegetation buffers, and to maintain water quality in the rivers of the Amazon Basin.