Biogeochemical Indicators to Evaluate Phosphorus Loading Impacts in the Everglades

The overall objective of the proposed research is to quantify the key microbial processes regulating mineralization and bioavailability of carbon and soil nutrients in Everglades soils. The experimental approach proposed in this research will provide predictive capability on the influence of nutrient loading on microbial processes in soil and water column of the eutrophic and oligotrophic areas of the Everglades. This work is focused on the development of indicators of wetland eutrophication, a phenomenon that is presently threatening the Everglades. In order to develop efficient indicators of eutrophication several questions need to be addressed: 1) What biogeochemical processes are most sensitive to eutrophication? 2) What chemical substrates, intermediates, or end products of these processes most accurately reflect their rates? 3) Can information developed for one area be extrapolated to other wetlands within the region?

The central hypothesis of the proposed research is that rates of biogeochemical cycling of C, N, and P in wetlands can be used to indicate the wetland eutrophication, and that the concentrations of certain forms of these elements can accurately predict the rates ecological potent processes. The objectives of the research are to: 1) Identify the key biogeochemical processes impacted by nutrient loading and measure the rates of these processes along the nutrient gradient, and 2) develop relationships between a process and its related easily measurable indicator. The proposed research will focus on key biogeochemical processes regulating the fate of nutrients in the water column, at the soil-water interface, and in the underlying soil at various spatial and temporal scales. This will be accomplished by developing information on easily measurable parameters for sites receiving different P loadings. The resulting relationships between processes and associated easily measurable parameters will be used to extrapolate the information to a large number of sites.