Rhizophora mangle occurs worldwide in coastal and estuarine areas of the tropics and subtropics to about 28° in both the northern and southern hemispheres. In the Indian River Lagoon, red mangroves are common landscape features to approximately 28° North, around the vicinity of Merritt Island. North of this location is the transition zone where mangrove forests gradually give way to salt marshes. Frost stress north of the transition zone prevents red mangroves from becoming established.