Carbon Dioxide Evasion from Fluvial Environments of Amazonia: A Major Sink for Terrestrially Fixed Carbon and Tracer of Ecosystem Processes

University Of Washington, Seattle WA

Investigators

Abstract

Determining the fate of CO2 has important consequences to the environment. Forests, particularly in the wet tropics may be very large carbon sinks. Recent evidence suggests that the Amazon may be a net sink of atmospheric CO2, storing 1-9 Mg C / ha/ yr. This project seeks to understand the role of CO2 outgassing, or evasion, from the Amazon River system in the carbon cycle of this important mosit tropical forest ecosystem. The working hypothesis of this research is that CO2 evasion returns as much carbon to the atmosphere as is sequestered in upland forests on an interannual basis. Export of organic material from upland forests to fluvial environments is the primary source of carbon that is eventually respired in rivers and evaded as CO2. The field work associated with this project will samplecharacteristic sub-basins of the Amazon to determine the spatial and temporal variation in CO emission. The 3-year project will be a joint effort between researchers at the University of Washington and the Centro de Energia Nuclear na Agricultura and will model whole ecosystem carbon flux of the Amazon River system.