Hydrological and nutrient budgets of freshwater and estuarine wetlands of Taylor Slough in Southern Everglades, Florida (USA)

Hydrological restoration of the Southern Everglades will result in increase d freshwater flow to the freshwater and estuarine wetlands bordering Florid a Bay. We evaluated the contribution of surface freshwater runoff versus at mospheric deposition and ground water on the water and nutrient budgets of these wetlands. These estimates were used to assess the importance of hydro logic inputs and losses relative to sediment burial, denitrification, and n itrogen fixation. We calculated seasonal inputs and outputs of water, total phosphorus (TP) and total nitrogen (TN) from surface water, precipitation, and evapotranspiration in the Taylor Slough/C-111 basin wetlands for 1.5 y ears. Atmospheric deposition was the dominant source of water and TP for th ese oligotrophic, phosphorus-limited wetlands. Surface water was the major TN source of during the wet season, but on an annual basis was equal to the atmospheric TN deposition. We calculated a net annual import of 31.4 mg m( -2) yr(-1) P and 694 mg m(-2) yr(-1) N into the wetland from hydrologic sou rces. Hydrologic import of P was within range of estimates of sediment P bu rial (33-70 mg m(-2) yr(-)1 P), while sediment burial of N (1890-4027 mg m( -2) yr(-1) N) greatly exceeded estimated hydrologic N import. High nitrogen fixation rates or an underestimation of groundwater N flux may explain the discrepancy between estimates of hydrologic N import and sediment N burial rates.