Thomas W. Doyle and Kenneth W. Krauss
U.S. Geological Survey, National Wetlands Research Center, Lafayette, LA USA

Major restoration projects have been proposed to restore freshwater flow across the Tamiami Trail (U.S. 41) into coastal marshes and estuaries of the northern Everglades including Big Cypress National Preserve and Ten Thousand Islands National Wildlife Refuge (TTINWR) with little or no understanding of the hydrologic coupling and potential impact to vegetation communities. Monitoring activities and models are needed to assess the hydrologic exchange across the Tamiami Trail and at the estuarine interface within the coastal watersheds of Ten Thousand Islands NWR. Under the proposed Picayune Strand Restoration Project, plugs and culverts will be installed to shunt more freshwater across the Tamiami Trail north-to-south akin to historic flows which will alter the stage, discharge, timing, and distribution of flow across the marsh/mangrove coastal margin.

Monitoring activities within the coastal ecosystems of south Florida have largely been confined to a few riverine settings, most notably Taylor Slough and Shark River, in the southern Everglades. Hydroperiod calculations for existing research sites in these watersheds and at TTINWR indicate that basin mangrove settings act more like impoundments with greatly reduced ebb and flood cycles relative to gaging stations in rivers and tidal creeks. Coupling of the regional or riverine hydrology with backswamp locations varies by location and is yet poorly described and under-represented by current hydrology networks. An expanded local network of gaging stations at TTINWR is underway to provide needed data for predicting backswamp hydroperiod and hydrologic coupling under different schedules and rates of freshwater pulsing.

A landscape simulation model, SELVA-MANGRO, was developed for mangrove forests of south Florida to investigate the potential impacts of climate change and freshwater flow on the quality and distribution of future mangrove habitat. The SELVA model administrates the spatial articulation of the landscape composed of habitat units and forcing functions that predict changes in hydrology and disturbance. MANGRO is an individual-based model composed of a set of species-based functions predicting the growth, establishment, and death of individual trees. Applications of the SELVA-MANGRO model for the Everglades region shows that freshwater marsh/swamp habitats will be displaced as the tidal prism increases over time as it moves upslope in the absence of hydrologic restoration. Historic map sets have been digitized to determine the process and pattern of mangrove migration with the drawdown and drainage of the Everglades over the last century. The SELVA-MANGRO model will be parameterized for TTINWR to predict how increasing freshwater flow and sea-level rise will impact future habitat quality and distribution.

Contact Information: Thomas W. Doyle, U.S. Geological Survey, National Wetlands Research Center, 700 Cajundome Blvd., Lafayette, LA 70506, Phone: 337-266-8647, Fax: 337-266-8592, Email: tom_doyle@usgs.gov

(This abstract is from the 2006 Greater Everglades Ecosystem Restoration Conference.)

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