Mangroves on the move
Mangroves are a group of salt-tolerant trees that thrive in coastal areas. In Florida, mangroves dominate most shorelines in the southern and central portion of the state. Mangroves are tropical plants that cannot tolerate freezing temperatures. In areas where frost and freezes are common, shorelines are dominated by cold-hardy marsh grasses. In the absence of freezing, mangroves can out-compete marsh grasses by growing taller than and eventually shading out the grasses. Thanks to warming temperatures, mangroves are becoming more common along Florida’s northern shorelines, too. Areas seeing increases in mangroves include Cedar Key to Pensacola on the Gulf of Mexico coast and Daytona Beach to St. Augustine on the Atlantic coast.
The mighty mangrove
Mangroves and Florida residents, especially shoreline property owners, have a complicated relationship. Many people intuitively know that mangroves have a multitude of environmental benefits. They provide a barrier that slows down storm surge, provide habitat for birds and fish, and trap pollutants that would otherwise flow into waterways. Despite these and many more beneficial environmental services, mangroves are often maligned by homeowners and others who want to view and access the waterfront. It is true that mangroves can grow tall and block views and healthy mangrove stands form dense tangles of branches and roots that make access through them difficult. In fact, many of the environmental benefits are directly derived from their tall height and density of vegetation. To illustrate this, check out the video below on how a thick stand of mangroves dissipates almost all of the incoming wave energy!
A recent study looking at the value of mangroves for storm and property protection in Florida found some amazing results, quoted below.
“…mangrove forests in Florida provided significant flood damage reduction benefits annually, across multiple storms, and during catastrophic events like Hurricane Irma. In Collier County, mangroves reduced annual flood risk by 25.5% to properties behind them. Many areas in the county received over $1 million in benefits every year in flood damage reduction benefits due to the mangroves in front of them.
The value of mangrove forests during Hurricane Irma was also very high. Mangroves averted $1.5 billion in storm damages, amounting to a 25% savings in counties that have mangroves. They also protected more than 626,000 people across Florida.”
-The Nature Conservancy
Managing or enhancing mangroves
Property owners who wish to manage the height of their mangroves or create access paths through trimming should contact the Florida Department of Environmental Protection for a consultation. Mangroves are protected in Florida and there can be large fines associated with illegal trimming. Property owners who want to enhance their shorelines by adding mangroves can do so through exploring the creation of a living shoreline that incorporates mangrove plantings. Many native plant nurseries carry and sell mangrove seedlings to the public. If you are considering a living shoreline, reach out to your local UF/IFAS Extension office for assistance!
Learn more about Florida’s mangroves