Fire is critical to the survival of the pineland and prairie ecosystems of the Everglades.
Pines and many other plants that grow in this habitat thrive in open sunny areas. Periodic fires burn through the pines, killing back hammock species that would otherwise take over, by casting shade with their dense canopies. Within 15 to 25 years a fire-free, shade intolerant pine fores would be replaced by subtropical hardwoods. In the event of a fire, however, these pineland plants do well. They have evolved with several adaptations for survival. The pineland habitat is capable of returning very quickly after a fire has passed.
The river of grass is perpetuated by fire. For thousands of years, lightning strikes ignited fires in the sawgrass prairies. Sawgrass fires actually improve the passage of water through the slough or shallow river basin, by burning back grass that would otherwise impede the vital flow of water through the Everglades. Fire not only improves habitat for wildlife by creating a mosaic pattern of vegetation, but also helps reduce large accumulation of fuels near hammocks or tree islands, which harbor a wide variety of subtropical plants less tolerant of fire.
Outlining the west coast of the Everglades are miles of mangrove forests. Interwoven within the mangrove forests are salt marshes and coastal prairies. Fires are mostly started in coastal prairies by lightning and burn hundreds of acres at a time. Because of the inaccessibility to this area, coastal prairie fires do not pose a threat to any human life or property and are permitted to burn under close monitoring. Allowing the fires to burn under Wildland Fire Use conditions prevents the encroachment of mangroves and exotic plant species into the fresh water prairies, and thus maintains a diverse natural ecosystem.
Scattered throughout the Everglades are Hammocks, tree islands that are higher in elevation than surrounding sawgrass prairie. Most plants growing in the hammocks are not well adapted to survive fire. Consequently, there are several naturally occurring protective features the system provides in the interest of self-preservation. Around the perimeter of a hammock there is a wet, moat-like depression that is created when limestone erodes away. Humidity and higher soil moisture levels inside the hammock are also a good fire deterrent. These features help to protect the many rare and endangered species of plants and animals that rely on this habitat for survival.