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

大豆在巴西亚马逊流域的扩张是地球上发生的最重要的土地利用变化之一。该项目研究大豆种植如何改变小流域溪流的径流和化学成分，以及大豆田的径流与大豆所取代的森林和牧场的径流有何不同。通过对森林、牧场和大豆田不同大小河流的比较，可以确定河流大小和河岸带结构对径流格局、水量和水质的影响，以及主要化学转化发生的流域位置（或热点）。计算机模型将使用流经土壤的水的化学性质和使用化学示踪剂的研究结果来确定流动路径。这些信息将使径流源对河流流量和河流水化学的贡献得以确定。研究结果将被用来研究大豆的扩张将如何影响亚马逊河流域的淡水沃茨在更大的区域。该项目有很大的潜力影响亚马逊河流域边界的土地使用决策，因为研究将在控制巴西亚马逊河流域大部分大豆生产和运输的财团的耕地上进行。该联盟旨在减少大豆生产对环境的影响，以进入欧洲市场。该实地基地将用于开发布朗大学实地课程，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. This informa-tion 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.