3rd UF Water Institute Symposium Abstract

Submitter's Name Danielle Watts
Session Name Posters - Understanding Natural, Anthropogenic and Legacy Sources of Nutrients
Category Understanding natural, anthropogenic and legacy sources of nutrients
Poster Number 55
Author(s) Danielle Watts,  School of Natural Resources and Environment, University of Florida, Gainesville FL 32611 (Presenting Author)
  Matthew Cohen,  School of Forest Resources and Conservation, University of Florida, Gainesville, FL 32611
  Carbon Accounting and Alternative Peat Accretion Equilibria in the Ridge Slough Everglades
  The historic ridge slough Everglades has been characterized as a peat basin with distinct elevation modes where vegetative communities differentiate based on local hydrology. It has been hypothesized that these ridges and sloughs represent alternative ecosystem configurations to achieve carbon equilibrium with the regional landscape, a hypothesis which invokes a homeostatic feedback between hydroperiods, primary production, and ecosystem restoration. The presence of a hydrologic gradient in response to modern hydrologic modification that spans conditions that are too dry and too wet to sustain this differentiation allows us to investigate deviation from this bi-stable equilibrium. Here we will present preliminary results of a study to measure the carbon dynamics of the two dominant patch types in the ridge slough patterned landscape along a gradient of hydrologic modification in Water Conservation Area 3. A two-pronged method is used, combining in situ measurements of net ecosystem carbon dioxide exchange with a simulation model designed to explore the role long-term water levels and ecosystem carbon budgets play in the development of observed soil elevation bimodality. In combination, the goals are to test whether the bi-stable states in the best conserved portion of the Everglades are in equilibrium, to investigate the degree to which net autotrophy has been lost with hydrologic modification, and to test the degree to which homeostatic carbon budgets can reproduce the persistence and loss of soil elevation bimodality. Demonstrating multiple peat accretion equilibria would provide mechanistic evidence for the existence of alternative stable states in the ridge-slough region, and aid in understanding the hydrologic requirements for landscape maintenance and restoration.