The Burn at Briggs Boardwalk
Part of the land that Briggs Boardwalk winds through is a scrub habitat. This habitat’s ground is made up of relatively loose sands. The sands are the remains of ancient sand dunes and beaches that were formed when ice melted many thousands of years ago, and the sea covered more of Florida than it does today.
The sand in a scrub habitat is poor in nutrition and does not hold rainwater near the surface. So the land supports mostly plants that have learned to eke out life in dry, nutrient-poor soil. At Briggs Boardwalk, two such plants are saw palmetto and scrub oak trees.
Over time, falling leaves, rotting wood, and other matter accumulate and can change the land so that it is able to support larger and more robust plants. You would think that scrub habitats would become more fertile habitats over time, and its plants, animals, and even insects would change to match the richer soil.
But Florida is struck by lightning more than any other state — it receives on average a whopping 1.45 million lightning strikes each year. These strikes sometimes cause fires that burn away the accumulated material and prevent the development of more fertile soil.
Native Americans also used fire to clear the land. The Calusa were one tribe of native Americans that inhabited southwest Florida. The remains of one Calusa shell mound are not more than a mile down the road from Briggs Boardwalk. The Miccosukee live in southwest Florida to this day and have reservation lands and leased lands nearby. The early pioneers arrived much later, but also used fire to clear the land.
Many of the plants that live in a scrub environment have adapted to survive these fires. Saw palmettos survive by keeping their trunks mostly horizontal on and under the sand, protecting the plant in a fire. Scrub oaks survive fires by regrowing themselve from their roots, if needed. Some saw palmettos and scrub oaks have been known to survive hundreds of years despite fires.
If the accumulated material is very thick when ignited, it may create a major fire that gets out of control and spreads to other habitats, especially if it’s windy. So, the Rookery Bay National Estuarine Research Reserve conducts contolled burns at Briggs and other spots in Rookery Bay every few years to remove the accumulated material.
Animals and insects also adapt to the scrub environment and the frequency of fires there. Gopher tortoises dig burrows in the loose sand for homes. The burrows protect not only the tortoise but as many as 350 other species of reptiles, mammals, insects and even birds from the heat of the sun and fires. For example eastern indigo snakes and burrowing owls often use tortoise burrows for escape.
Other animals and insects escape fires by running away, as raccoons and deer do, only to return when the fire is out.
Plants designed to survive fire quickly recover after a burn. The leaves on the saw palmetto fan above had already turned bright green shortly after a burn in 2013. The white-tailed deer looking at those succulent green leaves is probably thinking, “Hmmm, that looks like lunch.”
The bottom line is that periodic burns are necessary to maintain a scrub habitat and the plants, animals, and insects it attracts.
If you visit Briggs Boardwalk soon, you will see first-hand the results of a small controlled burn and be able to compare the burned area to the area on the other side of the walk that has not been burned — yet.
