The Biological Flora of Coastal Dunes and Wetlands: Avicennia germinans

Avicennia germinans (L.) L. is a pantropical, subtropical, and occasionally warm-temperate mangrove species that occurs on shorelines that have a broad horizontal tidal range. Also known as black mangrove, stands typically develop under anoxic, water-logged conditions in substrates of silt or clay. Black mangrove can tolerate salinity values ranging from 0 to 90 parts per thousand. Salt is excreted from salt glands on both leaf epidermal surfaces, and aerosol salt spray and salt crystals are frequently observed on the upper leaf epidermis. Avicennia germinans is viviparous. The embryos have no dormancy requirements, and there is no seed bank. This mangrove species has the northernmost distributional range of any mangrove species in North America. It occurs in Louisiana and northern Florida. Color-infrared photography and airborne video imagery techniques have been used successfully to map stands of black mangrove on subtropical coastal shorelines. Reforestation efforts using seedlings and saplings have been successful in several areas of the tropics and subtropics. Avicennia germinans stands play an important role in ecosystem functions as a natural barrier to coastal erosion caused by tropical storms, as habitat for a wide range of organisms in intertidal food chains, and as a carbon repository.