Carbon accumulation in Amazonian floodplain lakes: A significant component of Amazon budgets?

The
Amazon floodplains cover approximately 10% of the Amazon Basin and are composed
of predominantly anoxic sediments that may store large amounts of carbon. Our study
combines 210Pb derived sedimentation rates from four recently analyzed
sediment cores (n=4) with previously published organic carbon (OC) burial
estimates (n=18) to provide a broad, first order estimate of carbon accumulation
in Amazon floodplain lakes. The OC burial rates were of 266 ± 57 g C m-2
year-1. This rate is several fold greater than those reported for
lakes in arctic, boreal, temperate and tropical regions.  The large amount and spatial variation of OC
burial rates in these floodplain lakes highlights the need for increased
sampling efforts to better measure these potentially important components of
the Amazon Basin carbon budget.