A swamp is a wetland that is forested. Many swamps occur along large rivers where they are critically dependent upon natural water level fluctuations. Other swamps occur on the shores of large lakes. Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inundation. The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps. In the boreal regions of Canada, the word swamp is colloquially used for what is more correctly termed a bog or muskeg. The water of a swamp may be fresh water, brackish water or seawater. Some of the world's largest swamps are found along major rivers such as the Amazon, the Mississippi, and the Congo.
Swamps are characterized by slow-moving to stagnant waters. They are usually associated with adjacent rivers or lakes. Swamps are features of areas with very low topographic relief.
Swamps were historically drained to provide additional land for agriculture and to reduce the threat of diseases borne by swamp insects and similar animals[clarification needed]. Many swamps were also heavily logged, requiring construction of drainage ditches and canals. These ditches and canals contributed to drainage and, along the coast, allowed salt water to intrude, converting swamps to marsh or even open water. Large areas of swamp were therefore lost or degraded. Louisiana provides a classic example of wetland loss from these combined factors. Europe has probably lost nearly half its wetlands. As another example, New Zealand has lost 90 percent of its wetlands over the past 150 years. It is now understood that swamps provide valuable ecological services including flood control, fish production, water purification, carbon storage, and wildlife habitat. In many parts of the world, swamps are protected. In parts of Europe and North America, swamp restoration projects are becoming widespread. Often the simplest steps to restoring swamps are to plug drainage ditches and remove levees.
Land value, productivity and conservation
Swamps and other wetlands have traditionally held a very low property value compared to fields, prairies, or woodlands. They have a reputation for being unproductive land that cannot easily be utilized for human activities, other than perhaps hunting and trapping. Farmers, for example, typically drained swamps next to their fields so as to gain more land usable for planting crops.
Many societies now realize that swamps are critically important to providing fresh water and oxygen to all life, and that they are often breeding grounds for a wide variety of life. Indeed, floodplain swamps are extremely important in fish production. Government environmental agencies (such as the United States Environmental Protection Agency) are taking steps to protect and preserve swamps and other wetlands. In Europe, major effort is being invested in the restoration of swamp forests along rivers. Conservationists work to preserve swamps such as those in northwest Indiana in the United States Midwest that were preserved as part of the Indiana Dunes.
In Asia, tropical peat swamps are located in mainland East Asia and Southeast Asia. In Southeast Asia, peatlands are mainly found in low altitude coastal and sub-coastal areas and extend inland for distance more than 100 km (62 mi) along river valleys and across watersheds. They are mostly to be found on the coasts of East Sumatra, Kalimantan (Central, East,South and West Kalimantan provinces), West Papua, Papua New Guinea, Brunei,Peninsular Malaya, Sabah, Sarawak, Southeast Thailand, and the Philippines (Riley et al.,1996). Indonesia has the largest area of tropical peatland. Of the total 440,000 km2 (170,000 sq mi) tropical peat swamp, about 210,000 km2 (81,000 sq mi) are located in Indonesia (Page, 2001; Wahyunto, 2006).
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