At home here in southeast Michigan I’ve spent the last few years gaining a better understanding of the plant communities in my area. Although this is a heavily agricultural region, there are many pockets of various hardwood forests, savannahs, prairies, and wetlands harboring a variety of plants and animals. Most of my posts focus on these local organisms.
Every so often I get the opportunity to visit a completely different part of the country with a completely different assortment of plant communities. Compared to Michigan, the plant communities don’t come much different than those within Everglades National Park.
Here there is a great deal of diversity within small areas. Minor variations in elevation, soil types, and water can have a huge effect the plants that grow in a particular spot. Here’s a brief look at many of the communities I encountered along the main road. I’ll get into the specific plants more in the future.
Freshwater Marl Prairie
Filled with sawgrass (Cladium sp., Cyperaceae) and many other plants as well as a complex assemblage of microbes, freshwater marl prairies occupy large portions of the Everglades. During the summer wet season they’re inundated with shallow fresh water, but in the winter dry season much of the water is absent. This exposes a lot of the calcite-rich mudstone known as marl that blankets the ground:
Similar to the freshwater marl prairies are the freshwater sloughs. They’re deeper, transport more water, and host larger sawgrass.
Where the marl has been dissolved by water, areas of cypress trees (Taxodium sp., Cupressaceae) emerge from the sawgrass. Tolerant of standing water, there is a large group of them on the Pahayokee Trail. Along another stretch of the main road, dwarf cypress grow scattered amid less favorable conditions.
“Mangrove” is a catch-all term for a variety of small tropical trees that grow well in salty or brackish water. Over 100 species in many families are broadly considered mangroves, and a number are present in the Everglades. The most common are perhaps the red mangroves (Rhizophora mangle, Rhizophoraceae) with their characteristic prop roots. These roots provide for stability in water as well as oxygen uptake.
These trees are often seen along both inland and coastal bodies of water, but are also found in the wetter and saltier areas of the freshwater marl prairies:
As a fan of the hardwood forests of southern Michigan, my favorite plant communities in the Everglades are the hardwood hammocks. Scattered on little “islands” within the marl prairies and sloughs, these stands of large trees remind me of home. Unlike home, however, they are populated with very different plants.
I think some of the coolest trees are the West Indies mahogany (Swietenia mahagoni, Meliaceae)…
…gumbo limbo (Bursera simaruba, Burseraceae)…
…and Florida strangler fig (Ficus aurea, Moraceae):
The undergrowth is also dense with smaller trees like sabal palms (Sabal sp., Arecaceae):
The trees also host numerous epiphytes, plants that grow on other plants. With their aerial roots these plants obtain nutrients and moisture from the humid air and water immediately surrounding them:
Fallen trees also host many smaller herbs on “nurse logs”:
In some places the prairies and hammocks meet along open waterways filled with water lilies (Nymphaeaceae) and other aquatic plants. These spots are among the best for seeing alligators and turtles, as well as many birds.
The main road through the park ends at Florida Bay. The coast here is frequently battered by winds and storm surges, making it impossible for mangroves to survive. In their absence, short, scrubby plants eke out a living near the saline water.
Within the waters of Florida Bay itself, various marine plants like seagrass and algae thrive. Providing the basis for a diverse food web, these plants help feed many animals including coral, sponges, and fish.
There are several other plant communities I failed to photograph on my journey through the Everglades. Altogether, however, it was amazing to see how quickly these areas changed from one to the next over short distances. The Everglades are definitely a plant-lover’s paradise.