A swamp is a wetland that is forested[1]. Many swamps occur along large rivers, where they are critically dependent upon natural water level fluctuations[2]. Other swamps occur on the shores of large lakes[3]. Some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation.[4] The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps. The water of a swamp may be fresh water, brackish water or seawater. Some of the worlds largest swamps are found along major rivers such as the Amazon, the Mississippi, and the Congo[5].
Swamps are characterized by very slow-moving waters. They are usually associated with adjacent rivers or lakes. In some cases, rivers become swamps for a distance. 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 born by swamp insects and similar animals.[6] Many swamps were also heavily logged, which also required construction of drainage ditches and canals. These contributed as well to drainage, and, along the coast, allowed salt water intrusion that converted swamps to marsh or open water.[7] Large areas of swamp were therefore lost, or degraded. Louisiana provides a classic example of wetland loss from these combined factors.[8] Europe has probably lost nearly half its wetlands.[9] As another example, New Zealand has lost 90 percent of its wetlands over the past 150 years.[10] It is now appreciated that swamps provide valuable ecological services including flood control, fish production, water purification, carbon storage, and wildlife habitat.[11] In many parts of the world swamps are protected. In parts of Europe and North America, swamp restoration is becoming widespread[12][13]. Often the simplest steps to restoring swamps are to plug drainage ditches and remove levees.[14]
The largest swamp in the world is the Amazon River floodplain, which is particularly significant for its large number of fish and tree species[15][16][17].
The Sudd and the Okavango Delta are Africa's best known marshland areas.
The Vasyugan Swamp is a large swamp in the western Siberia area of the Russian Federation. This is one of the largest swamps in the world, covering an area larger than Switzerland. The Tigris-Euphrates river system is a large swamp and river system in southern Iraq, traditionally inhabited in part by the Marsh Arabs.
Swamp in southern Louisiana
Atchafalaya Swamp at the lower end of the Mississippi River is the largest swamp in the United States. It is an important example of southern cypress swamp[18] but it has been greatly altered by logging, drainage and levee construction[19]. Other famous swamps in the United States are the Everglades, Okefenokee Swamp, Barley Barber Swamp and the Great Dismal Swamp. The Okefenokee is located in extreme southeastern Georgia and extends slightly into northeastern Florida. The Great Dismal Swamp lies in extreme southeastern Virginia and extreme northeastern North Carolina. Both are National Wildlife Refuges. Another swamp area, Reelfoot Lake of extreme western Tennessee and Kentucky, was created by the New Madrid earthquake of 1812. Caddo Lake, the Great Dismal and Reelfoot are swamps that are centered at large lakes. Swamps are often called bayous in the southeastern United States, especially in the Gulf Coast region.
Swamps and other wetlands have traditionally held a very low property value compared to fields, prairies, or woodlands. They have a reputation as being unproductive land that can't be easily 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.
Societies now generally understand that swamps are critically important in the processes of providing fresh water and oxygen to all life, and are often breeding grounds for a wide isolated variety of life. Indeed, floodplain swamps are extremely important in fish production[20]. Government environmental agencies (such as the Department of Natural Resources in the United States) 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[21]
The worlds largest wetlands include significant areas of swamp, such as in the Amazon and Congo River basins[22]. Further north, however, the largest wetlands are bogs.
- Atchafalaya National Wildlife Refuge, Louisiana, United States
- Big Cypress National Preserve, Florida, United States
- Barley Barber Swamp, Florida, United States
- Everglades, Florida, United States
- Great Black Swamp, Indiana/Ohio, United States
- Great Cypress Swamp, Maryland, United States, also known as Great Pocomoke Swamp
- Great Dismal Swamp, North Carolina/Virginia, United States
- Great Swamp National Wildlife Refuge, New Jersey, United States
- Green Swamp, Florida, United States
- Green Swamp, North Carolina, United States
- Honey Island Swamp, Louisiana, United States
- Hudson Bay Lowlands, Ontario, Canada
- Limberlost, Indiana, United States
- Louisiana swamplands, Louisiana, United States
- Mingo National Wildlife Refuge, Puxico, Missouri, United States
- Okefenokee Swamp, Georgia/Florida, United States
- Reelfoot Lake, Tennessee/Kentucky, United States
- Shu Swamp, New York, United States
- Congaree Swamp, South Carolina, United States
- ^ Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p.
- ^ Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p.
- ^ Wilcox, D.A, Thompson, T.A., Booth, R.K. and Nicholas, J.R. 2007. Lake-level variability and water availability in the Great Lakes. USGS Circular 1311. 25 p.
- ^ Swamp (from glossary web page of the United States Geological Survey)
- ^ Keddy, P.A., L.H. Fraser, A.I. Solomeshch, W.J. Junk, D.R. Campbell, M.T.K. Arroyo and C.J.R. Alho. 2009. Wet and wonderful: the world’s largest wetlands are conservation priorities. BioScience 59: 39-51.
- ^ Dugan, P. (ed.) 2005. Guide to Wetlands. Buffalo, New York. Firefly Books. 304 p.
- ^ Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p.
- ^ Keddy, P.A., D. Campbell, T. McFalls, G. Shaffer, R. Moreau, C. Dranguet, and R. Heleniak. 2007. The wetlands of lakes Pontchartrain and Maurepas: past, present and future. Environmental Reviews 15: 1- 35.
- ^ Dugan, P. (ed.) 2005. Guide to Wetlands. Buffalo, New York. Firefly Books. 304 p.
- ^ Peters, M. and Clarkson, B. 2010. Wetland Restoration: A Handbook for New Zealand Freshwater Systems. Manaaki Whenua Press, Lincoln, N.Z. ISBN: 978-0-478-34707-4 (online)
- ^ Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Chapter 11.
- ^ Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p.
- ^ Environment Canada. 2004. How Much Habitat is Enough? A Framework for Guiding Habitat Rehabilitation in Great Lakes Areas of Concern. 2nd ed. 81 p.
- ^ Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Chapter 13.
- ^ Goulding, M. (1980). The Fishes and the Forest: Explorations in Amazonian Natural History. Berkeley, CA: University of California Press.
- ^ Lowe-McConnell, R. H. (1975). Fish Communities in Tropical Freshwaters: Their Distribution, Ecology and Evolution. London: Longman
- ^ L.H. Fraser and P.A. Keddy (eds.). 2005. The World’s Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge, UK. 488 p.
- ^ Conner, W. H. and Buford, M. A. (1998). Southern deepwater swamps. In Southern Forested Wetlands: Ecology and Management, eds. M. G. Messina and W. H. Conner, pp. 261–87. Boca Raton, FL: Lewis Publishers.
- ^ Reuss, M. (1998). Designing the Bayous: The Control of Water in the Atchafalaya Basin 1800–1995. Alexandria, VA: U.S. Army Corps of Engineers Office of History.
- ^ Lowe-McConnell, R. H. (1975). Fish Communities in Tropical Fresh waters: Their Distribution, Ecology and Evolution. London: Long man
- ^ Hughes, F.M.R. (ed.). 2003. The Flooded Forest: Guidance for policy makers and river managers in Europe on the restoration of floodplain forests. FLOBAR2, Department of Geography, University of Cambridge, Cambridge, UK. 96 p.
- ^ L.H. Fraser and P.A. Keddy (eds.). 2005. The World’s Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge, UK. 488 p.