THE EVERGLADES — Fire is a natural part of the South Florida ecosystem. In a Dec. 3 University of Florida Everglades Research and Education Zoom seminar, Rachel Taylor of the Florida Fish and Wildlife Conservation Commission explained how they use controlled burns to mimic the way Mother Nature managed the Everglades.
“For thousands of years, fire has been part of the Everglades ecosystem,” she explained. “Both plants and animals have adapted to life with fire here.”
The Everglades Complex of Wildlife Management Areas (WMAs) covers 736,881 acres and includes Everglades and Francis S. Taylor WMS, Holey Land WMA and Rotenberger WMA. The WMAs are part of the “River of Grass” that once extended from Lake Okeechobee to Florida Bay.
Taylor explained the extensive levee and canal system that made it possible for millions of people to live in South Florida altered the hydrology of the Everglades. Lack of cyclical natural fires in the Everglades can lead to catastrophic wildfires, she said.
To mimic the way nature managed the Everglades, FWC burns about 8,000 acres a year with controlled burns. Taylor sawgrass is the dominate vegetation and main source of fuel that carries fire in the Everglades. It regenerates quickly after a fire.
She said burns range from less than 500 acres to more than 3,000 acres. Special care is taken with the tree islands that dot the landscape. Prescribed burning around tree islands decreases the buildup of vegetation around the tree islands. Left unburned, the vegetation around the islands could fuel wildfires that would endanger the islands themselves. The tree islands provide habitat and refuge for many animals, stop over resting areas for migratory birds, and terrestrial refuge for upland wildlife during the rainy season and especially during high water conditions.
In addition to burning off the buildup of dead vegetation, fire releases nutrients back into the soil, Taylor explained. Fire help to control invasive vegetation. After a burn, an area can be replanted with native plants. Fire can reduce parasite populations, she said. It also improves access for wildlife foraging.
The hydroperiod is the main limiting factor for the success and frequency of burns, she said. Water levels in the Everglades can vary widely. “Burns are conducted whenever we can get the right conditions,” she explained. Most burning is done in winter or early spring when water levels are usually stable.
Boundaries of and size of burn are influenced by vegetation communities in that area, water levels and specific objectives of the burn.
Within a burn area, FWC fire teams leave scattered areas of unburned vegetation to provide refuge cover for wildlife.
Each year, FWC creates a burn plan with proposed burn areas within the 414,678 acres of burnable land. They use natural firebreaks such as sloughs or wet prairie as much as possible. They also use airboats to flatten areas of vegetation 40 to 50 feet wide to create firebreaks. Firebreaks maintain a minimum of 4 inches of water.
FWC works with the Florida Forest Service to predict the impact smoke from the controlled burns will have in the area. After a preburn meeting, a test fire is intitiated within the burn unit to ensure burn conditions are right.
Most burns are ignited by people on the ground or from airboats or with tracked vehicles, but they sometimes use helicopters on larger burns. FWC still provides ground support from airboats during aerial burns.
After the fire, the area is mopped up to ensure there is no active combustion between 100 feet of firebreak. They also thoroughly inspect the burn area and adjacent areas.
FWC’s fire management plan can be challenging. “It’s a giant area and we have a relatively small staff,” said Taylor. “Working around high water events and recreation activities can be challenge.”