Collaborative Research: Influence of Land Use on Watershed Hydrology and Biogeochemistry at the Amazon Agricultural Frontier

大豆向巴西亚马逊盆地的扩张是地球上正在发生的最重要的土地利用变化之一。该项目研究了大豆种植如何改变到达小流域溪流的径流和化学成分，以及大豆田的径流与被大豆取代的森林和牧场的径流有何不同。对来自森林、牧场和大豆田的不同大小的溪流进行比较，将能够确定溪流的大小和河岸(溪边)带的结构如何影响径流类型、水量和水质，以及流域中发生主要化学转化的位置(或热点)。计算机模型将使用流经土壤的水的化学成分和使用化学示踪剂的研究结果来确定流动路径，从而能够确定径流来源对溪流和溪水化学的贡献。结果将被用来研究大豆扩张将如何影响更大范围内的亚马逊淡水。该项目具有很大的潜力影响亚马逊边境的土地使用决策，因为研究将在控制巴西亚马逊地区大部分大豆生产和运输的财团耕种的土地上进行。该联盟旨在减少大豆生产对环境的影响，以便进入欧洲市场。该现场将用于开发布朗大学的现场课程，并培训巴西、美国和德国的研究生和本科生。

The expansion of soybeans into the Brazilian Amazon Basin is one of the most important land use changes taking place on earth. This project examines how soybean cultivation alters the runoff and chemistry of water reaching streams in small watersheds and how runoff from soy-bean fields differs from that of the forests and pastures that the soybeans replaced. Comparisons among streams of different sizes from forests, pastures and soybean fields will enable determina-tion of how stream size and the structure of riparian (stream-side) zones influence runoff pat-terns, water quantity and quality, and the locations in watersheds where major chemical trans-formations take place (or hotspots). Computer models will use the chemistry of water flowing through the soil and results of studies using chemical tracers to identify flow paths, will enable the contributions of runoff sources to stream flow and stream water chemistry to be determined. Results will be used to examine how soybean expansion will influence Amazon fresh waters over larger areas.This project has high potential to influence land use decisions at the Amazon frontier be-cause research will be conducted on land farmed by the consortium that controls most of the soy-bean production and transport in the Brazilian Amazon. This consortium aims to reduce envi-ronmental consequences of soybean production in order to gain access to European markets. The field site will be used to develop a Brown University field course and to train Brazilian, U.S. and German graduate and undergraduate students.