Wetlands and Mangroves

By Rebecca Evered, Curriculum & Content Director, Greenspeak International

A wetland is an area of land where the soil is saturated with water. This can happen either permanently or seasonally, and the water can be fresh, salt or a combination of the two. Wetlands are the most biologically diverse of all ecosystems. Plant life found in wetlands includes mangroves, water lilies, grasses and many others. Animal life includes is varied and includes many different amphibians, reptiles, birds, insects and mammals.

Although they have few harvestable resources, wetlands are very important. In addition to their high levels of biodiversity, they also provide many ecosystem services like regulating floods and cleaning water. Due to their lack of natural resources, wetlands have been a victim of development for many years. Now that the importance of these areas has been realized, they are the focus of many conservation programs (like the Ramsar convention to protect migratory birds).

Mangrove is both the name of a type of plant, and also of a forest. These trees generally grow in salty or brackish (part salt, part fresh) water in tropical or subtropical areas. There are around 110 species of mangrove, all of which have special adaptations to help them survive in their salty, wet environment. These include pneumatophores (a snorkel like root that helps the mangrove get Carbon Dioxide), floating seeds, and a variety of ways to deal with excess salt and a lack of freshwater.

Mangroves protect the shores where they live from erosion, and damage from destructive waves. This is due to their extensive root system, which traps and holds sediment. This web of roots also provides a calm nursery environment for many young aquatic organisms such as crabs, fish and oysters. Because of this, and the large amount of nutrients stored in them, mangroves are vital to food webs.

Unfortunately, the importance of mangroves has only just been realized. They have historically been cleared due to their lack of interest as tourist attractions, and the suitability of their locations for shrimp and oyster farming. In recent years however, many programs have been put in place to protect them, and the development of this vital habitat has been slowed.

References

Hogarth, Peter J. (1999). The Biology of Mangroves. Oxford University Press, Oxford.
Mitsch, William J.; James G. Gosselink (2007-08-24). Wetlands (4th ed.). New York: John Wiley & Sons
Plaziat, J.C., et al. (2001). "History and biogeography of the mangrove ecosystem, based on a critical reassessment of the paleontological record". Wetlands Ecology and Management 9 (3): pp. 161–179.
Saenger, Peter (2002). Mangrove Ecology, Silviculture, and Conservation. Kluwer Academic Publishers, Dordrecht.
Teas, H. J. (1983). Biology and Ecology of Mangroves. W. Junk Publishers, The Hague.
Tomlinson, Philip B. (1986). The Botany of Mangroves. Cambridge University Press, Cambridge
Image from http://nl.wikipedia.org/wiki/Bestand:Mangroves.jpg