Florida Keys - Major Natural Communities

• Tropical hammocks
• Mangrove swamp
• Coastal salt march

Tropical Hammocks

This tropical community has very high species diversity and may contain over 100 species of trees and shrubs. The overstory characteristically consists of such trees as strangler fig, gumbo-limbo, poisonwood, pigeon plum, Jamaica dogwood, Florida thatch palm, black ironwood, and false mastic. White stopper, Spanish stopper, saffron plum, limber caper, and milkbark are common in the understory. Endangered plants found in tropical hammocks include prickly-apple, silver palm, mahogany, and Florida thatch palm. Migratory birds rely on the rich source of berries and insects in the hammocks to sustain them before crossing extensive open water areas to the south in the fall. These hammocks are the first landfall in the U.S. for many birds heading north in the spring. To learn more about the value of this natural community, the Commission is currently funding a study of feeding and habitat use of neotropical migratory songbirds. Tropical hammocks also provide important habitat for the Florida tree snail, white-crowned pigeon, Key deer, Key Largo woodrat, Key Largo cotton mouse, Florida brown snake, red rat snake and other common resident and migratory species.

Mangrove Swamp

Mangroves are found along tropical shorelines with little wave action. The red mangrove is easily identified by its prop roots and its location in dense stands closest to the ocean. Generally, black mangroves occur in the next zone and closest to the shore are the white mangroves. Buttonwood usually occurs in areas above mean high tide. The understory typically consists of glasswort, saltwort, salt grass, sea purslane, and sea oxeye. Several endangered plant species occur in this community including bay cedar, banded wild-pine, and worm-vine orchid. Mangrove swamps are habitat for the common snook, Key silversides, American crocodile, peninsula ribbon snake, osprey, black-whiskered vireos, mangrove cuckoo, and other common resident marine and terrestrial and migratory species.

Coastal Salt Marsh

This community is found interspersed with mangrove swamps and in the transition zone between mangroves and upland hammocks. Two endangered species that are found in this community are bay cedar and sea lavender. Coastal salt marshes are used by the American crocodile, American alligator, peninsula ribbon snake, Florida Keys mole skink, Lower Keys marsh rabbit, silver rice rat, roseate spoonbill, little blue heron, reddish egret, snowy egret, tricolored heron, white ibis, and other common resident marine, terrestrial, and migratory species.