From mangrove forests bordering coastal channels to American alligators floating though dimly lit cypress swamps, the Everglades offer some of the nation’s most iconic landscapes. It’s easy to understand why Everglades National Park hosts around a million visitors each year, but the landscapes right next door are just as important to Southwest Florida’s remarkable ecosystems and wildlife. That’s why we’re so interested in protecting Big Cypress National Preserve.
Covering over 729,000 acres of vast swamp (making it nearly as large as Rhode Island), Big Cypress National Preserve is home to a massive amount of freshwater critical to the health of the neighboring Everglades and marine estuaries that run along the Florida’s southwestern coast. During Southwestern Florida’s wet season (May-October), consistent rains flood the area, leaving it under a layer of surface water. During the rest of the year, that water slowly drops and exposes the ground beneath.
Natural irregularities in the bedrock below the surface create minor differences in elevation, so different areas spend a different amount of time underwater each year. This time spent underwater is known as the habitat’s hydroperiod. Within the preserve’s 729,000 acres, different hydroperiods have created five distinct habitats, each of which support their own plant and animal communities. These habitats are cypress swamps, estuaries, hardwood hammocks, pinelands, and prairies.
Cypress Swamps
An American Alligator floats through a cypress swamp in Big Cypress National Preserve. Credit: Jaimie Tuchman, Adobe Stock.
Highlighted wildlife: American alligators
Highlighted plant life: ghost orchid
The understories of cypress swamps have a variety of woody plants, like buttonbushes, cocoplums, willows, and wax myrtles; but they are, of course, dominated by bald cypress trees—giving cypress swamps the distinct look they’re famous for. Growing on the trunks and branches of cypress trees, you can find epiphytes (or airplants) that wrap themselves around the tree in lieu of growing roots into the earth below. The epiphytes in Big Cypress (most notably, bromeliads and orchids) are photosynthetic, relying only on sunlight and rain for the nutrients and moisture they need to survive.
One of the most interesting features of cypress swamps is the presence of solution holes. Solution holes are sunken-in depressions in the limestone bedrock beneath the water’s surface that have been broken down from the acidic byproducts of decomposing plants. As the limestone begins to dissolve, cypress trees extend their roots into cracks in the bedrock and take firm hold. Larger solution holes are deep enough to hold water year-round but too deep for cypress trees to grow in, which creates a perennial pool of water. This permanent little pond acts as an important refuge for alligators, river otters, and other aquatic animals who need access to deeper water all year long.
Gaudy Sphynx Moth and Ghost Orchid. Credit: Nicholas Larghi.
Estuaries
A cluster of red mangroves creates a sanctuary for small aquatic species. Credit: rsgphoto, Adobe Stock.
Highlighted wildlife: Florida manatee
Highlighted plant life: red mangroves
Located along the southwestern border of the preserve, the freshwater from Big Cypress’s swamps meets the saltwater from the Gulf of Mexico. This mixture of fresh and saltwater is called brackish water, and it’s what makes estuaries one of the most productive ecosystems in all of nature. Mangrove trees—which you’ll recognize by their iconic finger-like prop roots—are responsible for that level of productivity.
All three species of mangrove in the Preserve (red, black, and white) are incredibly resilient, and can grow in both fresh and saltwater areas of the preserve. As mangrove leaves die and fall from the trees’ branches, they’re broken down into detritus. As they decompose, the leaves’ nutrients become trapped in the prop roots of red mangroves, which creates the perfect haven for smaller marine creatures, like shrimp, crabs, small fish, and snails.
In turn, the dense populations of these smaller creatures draw crowds of hungry marine fish, like snook, spotted seatrout, redfish, and more. Wading birds like great egret, blue heron, and brown pelicans are also abundant in the Preserve’s estuaries, as they can capitalize on the estuaries’ marine animal forage and build rookeries in the trees above. Manatees, who spend eight hours a day eating, love the abundance of aquatic plants in the area, too.
A Florida Manatee floating along in a Southwestern Florida estuary. Credit: Eric Carlander, Adobe Stock.
Hardwood Hammocks
Higher elevation keeps the floor beneath cabbage palms dry in hardwood hammock habitats. Credit: mtilghma, Adobe Stock.
Harwood hammocks have more elevated bedrock than most habitats in the region, bringing their elevation to roughly 13 feet above sea level. This elevation keeps the habitat’s hydroperiod much lower—between 10-45 days per year—although it still receives plenty of rain during the wet season. This combination of solid ground under-foot and plenty of precipitation makes hardwood hammocks appear similar to a tropical forest with a rich diversity of epiphytes, ferns, lichens, and vines.
Firmer ground allows for oak, wild tamarind, maple, and cabbage palm trees to grow tall, creating a dense overhead canopy. This canopy, which keeps the understory much cooler during the hot summer months, creates enough shade to prevent many plants to grow at ground level. Combine this lack of ground-level vegetation with a shorter hydroperiod, and you get a habitat perfect for larger land animals to explore.
Both Florida panthers and Florida black bears take advantage of the cooler temperatures and freedom to roam offered by hardwood hammocks. Panthers, which are carnivorous, develop home ranges of about 200 square miles. Within this range, they love to lounge in the shade of the hardwood hammocks by day, and hunt by night, preying on things like white-tailed deer, wild hogs, rabbits, and racoons. Black bears, on the other hand, like to lazily forage for saw palmetto berries and cabbage palm hearts when they aren’t napping in the shade.
A Florida panther steps past a camera trap at night. Credit: fStop Foundation.
Pinelands
Saw palmettos and South Florida slash pines dominate South Florida’s pineland landscapes. Credit: Billy McDonald, Adobe Stock.
The pinelands—which have a hydroperiod between 20-60 days per year—have two different types: the first has an understory full of saw palmettos and little else, while the second is filled with mixed grasses. The overstory of both types of pinelands is almost completed dominated by South Florida slash pines.
Frequent fires clear out pineland habitats of grasses, shrubs, and many trees, but slash pines have evolved to thrive in this kind of landscape, allowing it to outcompete other vegetation. The slash pine’s taproots are longer than those of similar species, and its needle size is shorter than those of its northern cousin. Additionally, heat from fires actually helps slash pinecones to open up and expose their seeds. These seeds, available as one of the only remaining things on an otherwise burnt and bare floor, are targeted as the only available food by birds, insects, and rodents, which transport and disperse slash pine seeds even further.
The resilience of slash pines makes the pinelands excellent habitat for the endangered red-cokcaded woodpecker, as they prefer to make their home cavities in more mature and resilient trees. In the pinelands, you can also find the threatened big cypress fox squirrel, which are known for the long, bushy tails, and their ability to leap great distances.
A red-cockaded woodpecker. Credit: Greg Lavaty, Flickr.
Prairies
Cypress domes sitting behind a stretch of sawgrass prairie. Credit: mtilghma, Adobe Stock.
Prairies in Big Cypress National Preserve are mostly treeless, open grasslands that have a hydroperiod between 50-150 days per year. The two types of prairies present in the Preserve, wet and dry, are based upon the vegetation growing there, rather than the amount of standing water present. Although you can find standing water in the Preserve’s prairies for nearly half of the year, the water is rarely any deeper than 20 centimeters, even during the wet season. Similar to pinelands, fires are an important part of the ecological structure of prairies. Although natural burns only occur every five years or so, this fire kills off woody plants that would usually out-compete and force out the prairie plant species.
Throughout Big Cypress’s wet prairies, the ground is covered with a thick mat of periphyton, which is a blend of algae, microbes, and detritus. In a strange way, periphyton benefits wet prairies like mangroves benefit estuaries, because it provides food for forage species, which bring more hungry animals around. While flies, snails, and tadpoles consume this plant, they lay eggs. During the rainy season, the tadpole and insect larvae will hatch, creating a buffet for reptiles, amphibians, and wading-birds of all shapes and sizes.
In addition to wading-birds and their prey, the Preserve’s prairies are home to marsh rabbits, which forage on the area’s grasses, leaves, and bulbs. Although they’re a close relative to another one of Florida’s rabbit species, eastern cottontail rabbits, marsh rabbits have shorter ears and hind legs, so they usually walk around instead of hop. When looking for more food or avoiding predators, they can even swim!
A marsh rabbit hiding out in South Florida. Credit: Wirestock Creators, Adobe Stock.