Editor's Summary
28 July 2005
Amazon basin blues
Rivers and their surrounding environments have received little attention in studies addressing regional carbon budgets and global climate change. But recent evidence suggests that Amazonian rivers outgas a significant amount of carbon dioxide. An extensive geochemical survey of rivers in the Amazon basin now finds that the dominant source of carbon dioxide is the respiration of organic matter that is less than five years old, probably originating from near-stream vegetation. Although most of the organic matter transported by these rivers is tens to thousands of years old, it is this small rapidly cycling pool of organic matter that is responsible for the large carbon dioxide fluxes from the rivers to the atmosphere in the humid tropics.
News and Views: Carbon cycle: The age of the Amazon's breath
The inorganic carbon carried in rivers of the Amazon basin seems to originate largely from the decomposition of young plant material — a finding that improves our understanding of the role of rivers in the carbon cycle.
Peter A. Raymond
doi: 10.1038/436469a
Letter: Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers
Emilio Mayorga, Anthony K. Aufdenkampe, Caroline A. Masiello, Alex V. Krusche, John I. Hedges, Paul D. Quay, Jeffrey E. Richey and Thomas A. Brown
doi: 10.1038/nature03880
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