Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: Rates, drivers, and sources of error
Article first published online: 5 SEP 2012
©2012. American Geophysical Union. All Rights Reserved.
Journal of Geophysical Research: Biogeosciences (2005–2012)
Volume 117, Issue G3, September 2012
How to Cite
2012), Carbon and sediment accumulation in the Everglades (USA) during the past 4000 years: Rates, drivers, and sources of error, J. Geophys. Res., 117, G03026, doi:10.1029/2011JG001821., , , , and (
- Issue published online: 5 SEP 2012
- Article first published online: 5 SEP 2012
- Manuscript Accepted: 14 JUL 2012
- Manuscript Revised: 12 JUL 2012
- Manuscript Received: 31 JUL 2011
- Everglades National Park, National Park Service (US). Grant Number: ???
- South Florida Water Management District. Grant Number: ???
- 14C dating;
- carbon accumulation rates;
- subtropical wetland
 Tropical and subtropical wetlands are considered to be globally important sources of greenhouse gases, but their capacity to store carbon is presumably limited by warm soil temperatures and high rates of decomposition. Unfortunately, these assumptions can be difficult to test across long timescales because the chronology, cumulative mass, and completeness of a sedimentary profile are often difficult to establish. We therefore made a detailed analysis of a core from the principal drainage outlet of the Everglades of South Florida in order to assess these problems and determine the factors that could govern carbon accumulation in this large subtropical wetland. Accelerator mass spectroscopy dating provided direct evidence for both hard-water and open-system sources of dating errors, whereas cumulative mass varied depending upon the type of method used. Radiocarbon dates of gastropod shells, nevertheless, seemed to provide a reliable chronology for this core once the hard-water error was quantified and subtracted. Long-term accumulation rates were then calculated to be 12.1 g m−2 yr−1 for carbon, which is less than half the average rate reported for northern and tropical peatlands. Moreover, accumulation rates remained slow and relatively steady for both organic and inorganic strata, and the slow rate of sediment accretion (0.2 mm yr−1) tracked the correspondingly slow rise in sea level (0.35 mm yr−1) reported for South Florida over the past 4000 years. These results suggest that sea level and the local geologic setting may impose long-term constraints on rates of sediment and carbon accumulation in the Everglades and other wetlands.