If you’ve been on one of our tours, or are looking to in the near future, you will likely be familiar with the Florida Mangroves. During our tours, we go through tunnels and islands created by these beautiful trees. But beyond being beautiful, these trees are incredibly fascinating and provide many ecosystem services throughout the state of Florida.
What makes these trees so unique is the fact that they live in ordinarily adverse conditions. Unlike most other trees, these plants live and thrive in salty, muddy, and hot habitats. Mangrove’s ability to thrive in these conditions is achieved through a complex root system, the use of air-breathing roots, and salt excretion on their leaves. If you got close enough to mangrove leaves, you might be able to see salt crystals.
Species of Mangrove Trees
The three common species found in Florida are the Red, White, and Black mangroves. Red mangrove trees form islands and live in the water. Red mangrove are identified by their round leaves and long, green seeds (or propagules). These trees have long, arching prop roots that keep them in place. Further inland we find their relative, the Black mangrove. These trees have round seeds (referred to as “seabeans”!) and more elongated leaves. These trees are identifiable because they are surrounded by pneumatophores. Pneumatophores are aerial roots that stick out of the ground. These roots are used for gas exchange, and other plants such as the cypress tree, also utilize these roots in development and growth. White mangroves live in dryer habitats, slightly upland from the beach. These trees have both prop roots and pneumatophores, and their trunks are a pale color. White mangroves are identifiable by their oval leaves and small seeds.
Mangroves reproduce through their seeds and propagules which float in the water and flow with a current until they become waterlogged and sink, planting themselves in a muddy substrate. Red mangrove propagules are able to drift for about a year, while white mangrove seeds drift for about a month before rooting themselves. Drifting with the ocean ensures that these seeds are able to be distributed throughout their habitat range. The drifting ensures juveniles are not in competition with existing older plants, making the beginning of their lives much easier.
While being beautiful and unique, mangrove trees provide important ecosystem services to the state of Florida; without these trees, the state wouldn’t exist! They stabilize shorelines through their root systems and also protect coasts from storms and wave impacts through a process called wave attenuation. Combined with other vegetation like seagrasses, mangroves can absorb between 70 and 90% of wave energy!
In addition to protecting coastlines, they act as nurseries and habitats for animals such as barnacles, mangrove crabs, fish, and a wide variety of birds. Fish and invertebrates (like crabs) lay their eggs here since the roots offer protection from predators, and the young juveniles spend their early time in these safe areas before heading out to the open ocean.
Birds know that these spaces are full of food, so begin nesting and building habitats here. Common species we see are ibises, egrets/herons, osprey, pelicans, and roseate spoonbills. These bird species are seen sunning themselves in the mangrove trees, or diving into the water for food.