Abstract > Introduction Marl Prairie Habitat & Community Everglades Hydrologic History Methods Results Discussion Conclusions Acknowledgements References Figures & Tables PDF

During the 20^th century, the hydrology of the greater Everglades ecosystem was altered to accommodate agricultural and urban needs, significantly altering the distribution and composition of plant and animal communities throughout the wetland (Davis and others, 1994; Light and Dineen, 1994; Lodge, 2005). Changes in both the timing and amount of water flowing through the extensive wetland system have been correlated with reduced numbers of tree islands and altered distribution and community composition of tree islands, sawgrass ridges, sloughs, and other marsh types throughout the system (Bernhardt and others, 2004; Willard and others, 2001a, 2006). Marl prairies occupy higher-elevation sites on either side of Shark River Slough (Fig. 1) and differ from most Everglades wetlands in occurrence of a calcitic substrate and short hydroperiods; these sites typically are dry for an average of nine months per year (Davis and others, 2005). The unique hydrologic and ecologic character of this habitat allows it to have the greatest plant species diversity of the Everglades, well-developed periphyton mats, and unique faunal assemblages. Concern about negative impacts of anthropogenic stressors has led to development of conceptual models to restore marl prairie habitats within an adaptive management framework (Davis and others, 2005). Central to restoration planning is determination of the pre-drainage distribution of marl prairies to predict their likely response to anticipated restoration strategies. Although marl prairie response to changes associated with the Central and South Florida Project (C&SF Project) in the mid-20^th century have been documented by field studies, little is known about impacts of hydrologic changes earlier in the century, which include construction of the Tamiami Trail, Hoover Dike, and other water control structures. We designed this pilot study to determine whether proxy evidence preserved in solution holes from marl prairies yields adequate data to evaluate temporal and spatial changes in marl prairie communities, to reconstruct pre-drainage (pre-20^th century) and post-drainage plant communities, and to determine whether observed ecosystem changes are correlated with hydrologic alteration of the wetland ecosystem.

Figure 1. a) Distribution of vegetation types in the greater Everglades ecosystem (from Willard and others, 2004. b) Plot of DEM (digital elevation model) data produced at 30 m grid spacing in southern Everglades (from Desmond, G., High Accuracy Elevation Data Collection: http://sofia.usgs.gov/exchange/desmond/desmondelev.html). Highest elevations (2.0-1.7 m) represent areas favorable for marl prairie habitats. [larger image]