02961naa a2200217 a 450000100080000000500110000800800410001902400260006010000140008624501810010026000090028152022510029065000180254165300210255970000180258070000190259870000160261770000180263370000250265177300670267615783872022-06-08       2006    bl uuuu     u00u1 u    #d7 a10.1002/hyp.62102DOI1 aNEILL, C.  aHydrological and biogeochemical processes in a changing Amazonbresults from small watershed studies and the large-scale biosphere-atmosphere experiment.h[electronic resource]  c2006  aThe Amazon Basin is the world?s largest tropical forest region and one where rapid human changes to land cover have the potential to cause signi?cant changes to hydrological and biogeochemical processes. The Large-Scale BiosphereAtmosphere Experiment in Amazonia (LBA) is a multidisciplinary, multinational research program led by Brazil. The goal of LBA is to understand how the Amazon Basin functions as a regional entity in the earth system and how these functions are changing as a result of ongoing human activity. This compilation of nine papers focuses on a central LBA question in the area of nutrient dynamics and surface water chemistry?how do changes in land use alter ?uxes of dissolved and particulate materials from uplands across riparian zones and down the channels of river corridors? These papers cover work conducted in small watersheds on a wide range of topics within the spirit and geographical focus area of LBA: water balance and runoff generation, nutrient transformations in riparian zones and stream channels, carbon ?uxes in water moving from land to water and the in?uence of soils on ?owpath structure and stream chemistry. Important new insights can be gained from these and other studies. Forest clearing for pastures results in a decrease in soil hydraulic conductivity that forces water into sur?cial ?owpaths throughout most of the rainy season across wide regions of the Amazon. Riparian zones along small forest streams appear to be very effective in removing nitrate arriving from the uplands, while forest streams take up nitrate at very low rates, allowing them to travel downstream for long distances. Although substantial, the contribution of dissolved organic C (DOC) to the carbon ?ux from forests to streams appears to be lower than the ?ux of dissolved inorganic C that is subsequently outgassed as CO2. Remaining key challenges within LBA will be to synthesize existing data sets on river networks, soils, climate, land use and planned infrastructure for the Amazon to develop models capable of predicting hydrologic and biogeochemical ?uxes at a variety of scales relevant to the development of strategies for sustainable management of the Amazon?s remarkable forest, soil and freshwater resources.  awater balance  aStream chemistry1 aELSENBEER, H.1 aKRUSCHE, A. V.1 aLEHMANN, J.1 aMARKEWITZ, D.1 aFIGUEIREDO, R. de O.  tHydrological Processesgv. 20, n. 12, p. 2467-2476, Aug. 2006.