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

In the natural Everglades system, seasonal rainfall and overflow of water from Lake Okeechobee dictated the hydrologic patterns. Water flowed southward from Lake Okeechobee along a gentle slope of 3 cm km^-1 (Kushlan, 1990), eventually reaching Florida Bay and the Gulf of Mexico through Shark River Slough and Taylor Slough (Fig. 1). The late 19^th to early 20^th century marked the first phase of intensive drainage efforts to render parts of the Everglades usable for agricultural and urban development (Light and Dineen, 1994). By 1930, four drainage canals (the North New River, Hillsboro, Miami, and West Palm Beach) were constructed, the Hoover Dike encircled Lake Okeechobee, and the Tamiami Trail was constructed, consisting of a combination of raised roads and culverts (Fig. 3a) (Deuver and others, 1986; Light and Dineen, 1994; Sklar and van der Valk, 2002). Even more extensive compartmentalization began in the 1950's with the construction of three Water Conservation Areas (WCA), which incorporate a series of canals, levees, and other water-control structures to control flooding within the northern Everglades (Fig. 3b) (Light and Dineen, 1994). By the late 20^th century, it was recognized that the health of the Everglades ecosystem and the quality and quantity of available water affected the economic and cultural health of south Florida, and the U.S. Federal and Florida State governments enacted the Comprehensive Everglades Restoration Plan (CERP). The CERP aims to achieve flow patterns similar to the historic hydrologic regime through modification and removal of existing water-control structures. It is assumed that the natural resilience of the wetland will allow its recovery to a more natural state.

One key to successful wetland restoration is an understanding of the natural processes that govern wetland development. We collected sediment cores from solution holes in marl prairies west of Shark River Slough to address several questions. Is the sedimentary record long enough to provide data on pre- and post-drainage vegetation? If pollen is preserved in these sediments, can marl prairie vegetation be distinguished from other wetland types? If plant community changes occurred, is the timing correlated with specific climatic or anthopogenic events? Do these data indicate changes in the spatial distribution of marl prairies through time? It is important to address these questions to accurately predict responses of marl prairie plant and animal communities to planned changes in water delivery associated with restoration efforts.

Figure 3. Map of water control structures in place in greater Everglades ecosystem. a) ~1930 AD b) ~1970 AD (post C&SF Project) (from Willard and others, 2006). Study area is highlighted in yellow. Core sites are indicated by black dots. [larger image]