Defining Wetlands
Wetlands are a general name used to define different kinds of wet habitats. For example, some types of wetlands are marshes, swamps, bogs and fens. Wetlands do not have to be wet all the time, but can remain dry for some periods of time. Some of the most important wetlands in fact may only be wet for seasons of the year. Under the Clean Water Act, wetlands are defined as, “Those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions.
Wetlands can be seen as the connection between land and water. The interaction of land, water, and the sun play an important role in creating a unique and productive ecosystem. Wetlands are unlike any other areas in the United States and are necessary for the survival of many plant and animal species. Without wetlands many of the already endangered plant and animal species will become extinct.
http://water.epa.gov/type/wetlands/what.cfm
http://www.ci.la.ca.us/san/wpd/e-news/solawetlands.htm