The Role of Fire in the Restoration of Everglades Wetland Communities
James W. Pahl and Curtis J. Richardson
Duke University Wetland Center
Nicholas School of the Environment and Earth Sciences
Durham, North Carolina, USA
Hydrological modification and nutrient loading from surface water inputs have led to alterations in the community structure of northern Everglades plant communities, where southern cattail (Typha domingensis) has been rapidly expanding into the natural mosaic of slough, sawgrass (Cladium jamaicense) marsh and tree island communities. We are investigating if community type and extent of soil nutrient enrichment influence whether fire can be used to control Typha expansion. Managed cover burns (surface water is present to prevent root or peat burn) encompassing three plant community types of interest - Cladium-dominated and Cladium-Typha mixed marshes, and Cephalanthus-Salix shrub communities fringing hardwood tree islands - were conducted by the Florida Fish and Wildlife Conservation Commission from March to October 2002 in Water Conservation Area 3a (WCA3a). The soils of WCA3a are generally considered to have a background soil nutrient status (< 500 mg P/kg dry weight). We established sites in these three community types in both burned and non-burned communities, and sampled for water, soil, and vegetation both before and after fire events. Surface and interstitial water chemistry response was highly variable both temporally and spatially between and within community type. We did observe short-term increases in interstitial phosphorus and both increased and decreased ammonium-nitrogen following burns. Preliminary analysis of vegetation response suggests that fire had mixed success in removing Typha from the community structure of mixed-species marshes while maintaining structure in non-Typha communities. We will present soil chemistry data to illustrate fire-induced changes in the peat matrix and relate that data to vegetation response.
James Pahl, Duke University Wetland Center, Nicholas School of the Environment and Earth Sciences, P.O. Box 90333, Durham, NC 27708-0333; PH 919-613-8007; FAX 919-613-8101; Email: