• Pa-Hay-okee Overlook

    Everglades

    National Park Florida

East Everglades Expansion Area

East Everglades Expansion Area
Location of East Everglades Expansion Area in Everglades National Park.
 
East Everglades Expansion Area

Treated melaleuca in the East Everglades Expansion Area. Left unchecked, melaleuca grows in dense stands called "heads" that prohibit growth of native plants, thereby destroying suitable habitat for native wildlife.

NPS photo

Acquisition

Everglades National Park acquired the East Everglades Expansion Area in 1989. At the time of acquisition, Australian pine and melaleuca already were present in this 109,000-acre area. Both species had colonized the short hydroperiod wetlands (rocky glades) that consist mostly of muhly grass (Muhlenbergia capillaris) and sawgrass (Cladium jamaicense). Melaleuca had also established in the relatively longer hydroperiod, tall sawgrass prairies of Shark River Slough. Brazilian pepper was abundant but scattered, primarily restricted to bayheads, tree islands, and disturbed sites. Treatment efforts to control these exotics have been ongoing since the area was acquired. The park focuses treatment on the East Everglades Expansion Area to preserve habitat for the Cape Sable Seaside Sparrow, a federally endangered species.

 
East Everglades Expansion Area boundary

The park boundary is obvious in this photograph, with park lands that have been cleared of melaleuca on the right in contrast with uncleared lands outside the park's jurisdiction on the left.

NPS photo

Quarantine Strategy

A progressional "surround and eliminate" quarantine strategy is being used, based on the understanding that the exotics are entering the park from seed sources outside the eastern boundary of the park. The dispersal mechanisms of the exotics have led to the establishment of more numerous and denser stands of exotics along the eastern boundary. Treating target species systematically from west to east removes them from the areas of least concentration in the western portions of Everglades National Park toward the higher concentrations near the eastern park boundary. This quarantine approach quickly restores the relatively undisturbed western habitat, allowing a more focused effort to suppress the denser concentration of exotics along the eastern park boundary.

 
Melaleuca seed pod

The stress of dying can cause the seed pod of a cut melaleuca tree to release its seeds.  Re-treatment of areas even lightly infested with melaleuca is required until the seed source has been exhausted.

NPS photo

Challenges

Since 2002, the park has received sufficient funds to complete the systematic initial treatment of approximately 97% (105,000 acres) of the East Everglades Expansion Area. Approximately 2,000 acres are still in need of initial treatment. Although it may appear as if the majority of work has been completed, much of the remaining untreated area is the area most densely infested with melaleuca. The seed source contained within the remaining untreated area could quickly re-infest treated areas and easily wipe out all of the progress made to date. In addition, follow-up re-treatments of other areas within the East Everglades Expansion Area are needed to prevent the loss of initial progress made over the past few years. Although expensive, treatment and re-treatment are necessary parts of the Everglades Exotic Vegetation Management Program.

 

Did You Know?

Did You Know?

Over the course of thousands of years, the natural communities of South Florida have become well adapted to the devastating effects of seasonal hurricanes. In fact, such storms are considered an important element in the long-term health of the Everglades.