Mangrove stilt roots

Title Info
Common name Mangrove, Red
Scientific name Rhizophora
Taxonomic group Rhizophoraceae
Source Dan L. Perlman
Ecosystems Wetlands, aquatic
Wetlands and aquatic Mangroves; Marshes, Swamps
Conservation Endangered ecosystems
Lessons Ecosystem Sampler; Aquatic systems
Location Pacific Coast,Costa Rica,North America
Red Mangrove stilt roots, <i>Rhizophora</i>, Costa Rica
Related materials: Mangroves

Rhizophora mangroves, Costa Rica.Rhizophora has evolved the stilt roots or prop roots seen here that get the main trunk of the tree out of the water in the difficult living conditions of alternately wet/dry, salty/fresh water. These roots also enable the plant to perform gas exchange above the level of the often water-logged soil. Although relatively few tree genera have evolved to be able to survive in these difficult conditions, those that are able to do so are very wide-spread. The genus Rhizophora, for example, exists throughout the tropics, all the way around the globe.

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 Unfortunately, in too many parts of the world, mangroves have been cut for charcoal or have been replaced by artificial shrimp ponds, which earn vast amounts of money for their owners for the very few years that they are productive (before they become fouled and must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).