DETECTING PRE-DRAINAGE BASELINE CONDITIONS OF WATER FLOW, HYDROLOGIC CONNECTIVITY, AND WATER QUALITY IN THE EVERGLADES

The Everglades is an outstanding example of a subtropical peatland with distinctive plant communities adapted to waters low in total dissolved solids and nutrients. Understanding baseline conditions in the Everglades before the past centuries drainage and flood control began is crucial to success of the Comprehensive Everglades Restoration Plan, but reliable tools for hindcasting are limited. Historical accounts and early research provide the best evidence that fundamental characteristics of the ecosystem have been substantially altered, including patterned microtopography and its accompanying diversity in macrophytes, as well as the makeup and function of the periphyton communities that comprise the base of the food chain. Along with being one of the potential drivers of ecosystem change, altered water quality provides an assessment tool in the form of environmental tracers that can help detect baseline conditions in the pre-drainage Everglades. Significant increases in major ions such as sodium, chloride, and sulfate, often accompanied by increasing concentrations of nutrients, are one important change that appears to have resulted over a large area of Everglades wetlands. We interpret those signatures in terms of the information they provide about changing flow regimes, water sources, hydrologic connectivity, and role of interactions between surface water and groundwater in the Everglades.