Home Preface Synopsis History of the Study Regional System Ecosystems - Freshwater and Terrestrial   -  System relations   -  Effects of man   -  Canals & lakes   -  Ponds & sloughs   >  Sawgrass marsh   -  Wet prairies   -  Pine forests   -  Cypress forests   -  Mixed swamp forests   -  Bay heads   -  Hardwood hammocks   -  Palmetto & dry prairies - Coastal - Man-dominated Hydrologic Systems Final Word References Appendices PDF version

Sawgrass marsh occupies about 70 percent of the remaining Everglades. In the northern Everglades the sawgrass is tall and dense; in the south it tends to be short and less dense, except where it forms a tear-shaped tail at the downstream end of tree islands. Sawgrass marsh ranges from almost pure stands to mixed stands. Herbaceous marsh plants that commonly occur with sawgrass include maidencane, arrowhead, and spikerush. Small trees and brush such as wax myrtle, holly, and willow are also mixed with sawgrass.

Sawgrass marsh usually occurs on land slightly higher than that of the sloughs and wet prairies but lower than that of bay heads and hardwood hammocks. Water inundates the marsh for varying periods during the year to depths ranging from a few inches to several feet; optimum inundation period is in the order of months. Soils differ, ranging from a thick peat to a thin veneer of marl over limestone.

Severity of fire is a major factor in the sawgrass marsh. Sawgrass often burns during the dry season, but the roots remain protected by moist soil; this type of fire serves to prune trees and brush from the sawgrass. In severe droughts, however, sawgrass roots may be burned and the community destroyed.

Approximately 200,000 ha (500,000 acres) of sawgrass have been destroyed, mainly in the northern Everglades (Birnhak and Crowder, 1974). The remaining sawgrass communities have been affected in varying degrees. Davis (1943) observed thinning of sawgrass in the northern Everglades which he attributed to drainage and subsequent soil subsidence and severe fires. Craighead (1971) reported that after severe fires, willow colonized large areas south of U.S. Highway 41 that were originally pure sawgrass stands.

Sawgrass marsh occupies about 70 percent of the Everglades. [larger image]

Large sawgrass marshes remain in the conservation areas and in Everglades National Park. It has been suggested that marshes in the conservation areas be used to renovate waste water from the coastal cities as a means of recycling and conserving freshwater now lost to the ocean. Recent studies (Steward and Ornes, 1973a, b, c) indicated that sawgrass has a low nutrient requirement and a limited capacity for removing nutrients from water; therefore it appears unlikely that sawgrass plants could be used effectively to renovate urban waste water with high nutrient concentrations without causing significant changes in the sawgrass communities. These studies further indicated that enrichment with phosphorus and potassium in amounts generally equivalent to that of sewage effluent resulted in dynamic shifts of associated plants in the marsh, including phytoplankton blooms that are indicative of a disrupted environment.