ESTIMATING AND COMPARING THE CARBON SEQUESTRATION POTENTIAL OF WETLANDS AND THE OCMULGEE RIVER FLOODPLAIN

This study estimates and compares the carbon stock in the Ocmulgee River Floodplain and Fall Line Hills District of the Georgia Coastal Plain. Due to periodic inundation in wetland and river floodplain environments, these areas share many of the same environmental conditions. They have similar hydrologic and geologic conditions, as well as similar types of vegetation characteristics. The carbon stock was estimated in tree stems, the soil organic layers, mineral horizons, and soil respiration rates. Tree stem diameter at breast height was measure in 10 by 10 meter plots, while soil organic carbon was quantified from soils collected within the plots. Respiration rates were measured using homemade respiration chambers and a Vernier CO₂ probe attached to a Vernier LabQuest 2 meter. The sampling locations within each site were in areas sharing visually similar characteristics. Carbon dioxide concentrations were measured over 15 minute intervals after initial chamber pressurization. Linear regression of the CO₂ concentrations and the dimensions of the monitoring chambers were used to calculate the rate of CO₂ released per second per unit area (ppm sec^-1/ meter²). Within the wetlands there were differences in plant cover, diversity, and abundance. Respiration rates within the wetlands varied widely; with initial rates ranging from 70 ppm s^-1/m², to 450 ppm s^-1/m².