The primary objective of this study is to determine how alterations in hydrology impact the carbon dynamics of Everglade fresh water marshes. Eddy covariance flux measurements will quantify carbon exchange (CO2 and CH4) from both short and long hydroperiod (the duration of inundation) marshes in the southern Florida Everglades. The expected results of these studies will lead to an improved understanding of how changes in wetland hydrology and vegetation structure influence the balance between the uptake and release of CO2 and CH4.The Everglade watershed provides an excellent opportunity to study the effects of hydroperiod on wetland carbon balance, especially since water management practices are likely to change substantially in the near future due to the implementation of the Comprehensive Everglades Restoration Plan. This watershed is also important due to its peat-forming wetlands that contain vulnerable stocks of soil carbon. Because wetland ecosystems are of great significance globally in sequestering carbon dioxide and releasing methane, and many are threatened by changes in land use and climate, research is needed to provide better estimates of their role in providing an overall carbon balance on regional and global scales.