Black mangroves

Title Info
Common name Mangrove, Black
Scientific name Avicennia
Taxonomic group Avicenniaceae
Source Dan L. Perlman
Ecosystems Wetlands, aquatic
Wetlands and aquatic Mangroves; Marshes, Swamps
Conservation Endangered ecosystems
Location Costa Rica,North America
Black Mangroves, <i>Avicennia</i>, Costa Rica
Related materials: Mangroves

Avicennia mangroves, Costa Rica. Avicennia has evolved pneumatophores, the short roots seen sticking straight up in this image. These structures enable the plant to perform gas exchange above the level of the often water-logged soil in the difficult conditions under which mangroves grow.

Mangrove swamps, also known as mangals, are very difficult habitats in which to live. Existing at the interface between land and ocean, mangrove swamps are alternately flushed by fresh water and salt water, and their water levels, oxygen levels, and salinity levels change throughout the day as tides move in and out. Plants in this habitat must be able to live under a very wide range of physical and chemical conditions, and very few are able to do so. Dealing with the high salt levels of sea water is a particular problem, and each mangrove species has either evolved methods for excluding salt or for expelling salt once it is absorbed. Mangrove forests function as critical nurseries for many marine species, as they trap and drop large amounts of nutrient rich material among their roots, and therefore play an important role in the economic lives of many tropical human communities. Unfortunately, in too many parts of the world, mangroves have been cut for charcoal or have been replaced by artificial shrimp ponds, which earn vast amounts of money for their owners for the very few years that they are productive (before they become fouled and must be shut down).