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

Marine Biological Laboratory, Woods Hole MA

Investigators

Abstract

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.