Using the natural abundance of the radioisotope (14C) to measure carbon flow and restoration performance in the Everglades Protection Areas

The tracking of changes in the abundances of ¹⁴C in nature is a powerful tool in ecological research and could be a useful means to track carbon flow through the Everglades and measure the results of our restoration efforts. Our recent studies show that ¹⁴C signatures can be used to estimate the relative contribution of the historic peat deposits to various C pools in the Everglades. Radiocarbon ages of dissolved organic C (DOC), particulate organic C (POC) and dissolved inorganic C (DIC) ranged from 2010 years before present (B.P.) to “>modern”. The old ¹⁴C ages of DOC and POC were found in impacted areas near the EAA in the northern Everglades.  In contrast, DOC and POC in pristine marsh areas had near modern or “>modern” ¹⁴C ages.  These data indicate that a major source of POC and DOC in impacted areas is the degradation of historic peat deposits in the EAA.  In the pristine areas of the marsh, DOC represents a mix of modern and historic carbon sources, whereas POC comes from modern primary production as indicated by positive D¹⁴C values.  A 60 - 70% turnover of DOC from the northern to the southern Everglades was estimated using radiocarbon data. Our study suggests that Δ¹⁴C measurements can be a useful indicator of the progress of ecosystem restoration in the Everglades. As a restored wetland moves towards its “original” or “natural” state, the ¹⁴C signatures of DOC should approach to that of modern atmosphere.