Mangrove – Unidentified Species*
Other Names: Red Mangrove, White Mangrove, Black Mangrove
Distinctive Characteristics: "Mangrove" refers to a variety of evergreen tree and shrub species that is specially adapted to salty waters, having evolved physiologically to overcome high salinity and frequent tidal inundations. They are an extremely important type of forest ecosystem for the planet. Because they live in a coastal zone, between fresh and salt water, they prevent soil erosion and build up land by catching sediment and debris between their roots, also protecting coral reefs from suffocating in silt. They are able to 'breathe' in oxygen through their bark.
What makes mangroves aesthetically beautiful is the exposure of their sturdy and delicately balanced root-stilted systems during low tides. Their long, thick roots plant themselves firmly into the sandy soil, creating an underwater landscape, while their aerial roots act as snorkels, exposed to the air to absorb massive amounts of CO2. Masses of propped roots break the waves and dissipate their force, protecting coasts even from tsunamis. Their seeds are adapted to their moving waterscape; the Rhizophora species have seeds that 'pre-germinate', growing while still in their pod on the tree, so that when they hit the mud, they are immediately able to root themselves.
Distribution: Mangrove forests are on tropical coastal regions throughout the world. This unidentified species is native to the Western coast of Madagascar. Elevation: sea level.
Ecosystem: Tropical and subtropical waters, where fresh water from rivers flows into the ocean. In Madagascar, most of the mangrove stands contain six species in four families: Rhizophoraceae (Rhizophora mucronata, Bruguiera gymnorrhiza, and Ceriops tagal), Acanthaceae (Avicennia marina), Lythraceae (Sonneratia alba), and Combretaceae (Lumnitzera racemosa).
Maximum Age: Some species are estimated at over 100 years old.
Maximum Height and Girth: Red Mangroves are the tallest, growing to 80 ft. (25 m); trunk circumference is not substantial.
Animal Community: Mangrove habitats provide a unique sheltered habitat for a great diversity of coastal and estuary species such as mussels, crustaceans, and barnacles; endemic and migratory birds; as well as insects, fish, turtles, and even crocodiles. In this way they bridge the food webs of both the ocean and land.
Threats and Conservation: Because mangroves reside in sensitive and vulnerable ecotones, they are in danger everywhere across the planet. Mangroves are increasingly threatened by pollution from development of urban areas, over-fishing, over-harvesting of wood, and erosion caused by deforestation. In Madagascar the massive deforestation of the island has led to a constant flow of red, salty soil into the sea. Rising sea levels due to climate change, are also a threat. Globally, the greatest threat is the over-conversion of mangrove areas into economic use for rice farming, salt harvesting and production, beach resort developments, shrimp aquaculture, and even dumps.
*In Madagascar, most of the mangrove stands contain six species in four families: Rhizophoracae (Rhizopora mucronata, Bruguiera gymnorrhiza, and Ceriops tagal), Acanthaceae (Avicennia marina), Lythraceae (Sonneratia alba), and Combretaceae (Lumnitzera racemosa). Other reported species are: Ceriops tagal, Xylocarpus granatum, and Heritiera littoralis (Rasolofo, 1993).