2nd UF Water Institute Symposium Abstract

Submitter's Name Danielle Watts
Session Name Poster Session: Hydrologic, Biogeochemical and Ecological Processes 2
Category Hydrologic, biogeochemical and ecological processes
Poster Number 242
Author(s) Danielle Watts,  University of Florida
  Matthew Cohen,  University of Florida
  Todd Osborne, University of Florida
  Hydrologic Controls on Ecosystem Respiration in the Everglades Ridge-Slough Mosaic
  The Everglades in South Florida is a large subtropical peat wetland. Hydrologic modification over the last century has lead to the widespread loss of the historic ridge slough patterning that was characteristic of the pre-drainage Everglades. The loss of pattern is best understood as a change in peat accretion dynamics leading to loss of soil elevation bimodality; altered water levels have increased respiration (drained conditions) or decreased productivity (impounded conditions), which has profoundly altered the feedbacks that previously maintained patchiness. The objective of this study is to determine what factors in regional hydrology control annual ecosystem respiration, and to examine the possibility of thresholds in hydrologic conditions where increased water levels do not have a reciprocal influence on ecosystem carbon flux. We present the first year (December 2008 through December 2009) of bi-monthly ecosystem respiration measurements taken at 64 locations along a gradient of hydrologic conditions in Water Conservation Area (WCA) 3A. A multivariate model is presented, predicting respiration based on hydrologic attributes (inundation probability, median water depth) and other environmental covariates (water temperature, pH, community type). This model comprises one half of ongoing investigations into hypotheses of multiple equilbria for carbon accretion, represented on the landscape by ridges and sloughs.