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70-634: WWT London Wetland Centre is a wetland reserve managed by the Wildfowl and Wetlands Trust in the Barnes area of the London Borough of Richmond upon Thames , southwest London , England , by Barn Elms . The site is formed of four disused Victorian reservoirs tucked into a loop in the Thames. The centre first opened in 2000, and in 2002 an area of 29.9 hectares was designated a Site of Special Scientific Interest as

140-711: A sink or a source of carbon, depending on the specific wetland. If they function as a carbon sink, they can help with climate change mitigation . However, wetlands can also be a significant source of methane emissions due to anaerobic decomposition of soaked detritus , and some are also emitters of nitrous oxide . Humans are disturbing and damaging wetlands in many ways, including oil and gas extraction , building infrastructure, overgrazing of livestock , overfishing , alteration of wetlands including dredging and draining, nutrient pollution , and water pollution . Wetlands are more threatened by environmental degradation than any other ecosystem on Earth, according to

210-507: A collection of captive wildfowl . It is host to regular lectures and events concerned with preserving Britain's wetland animals and was featured on the BBC television programme Seven Natural Wonders in 2005 as one of the wonders of the London area, with a focus on the region's parakeets , in an episode presented by Bill Oddie . The site contains a large visitors' building which is occasionally used as

280-402: A frequency and duration to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally included swamps, marshes, bogs, and similar areas.' For each of these definitions and others, regardless of the purpose, hydrology is emphasized (shallow waters, water-logged soils). The soil characteristics and

350-516: A low-water season (known popularly as summer), and a wet season (known popularly as winter) during which, the rivers flood the adjacent, low-lying forests. The climate of the basin is generally hot and humid . In some areas, however, the summer months (June–September) can bring cold snaps, fueled by Antarctic winds traveling along the adjacent mountain range. The average annual temperature is around 25-degree and 28 degree Celsius with little to no distinction between summer and winter season. Amazonia

420-1248: A polar climate, wetland temperatures can be as low as −50 °C (−58 °F). Peatlands in arctic and subarctic regions insulate the permafrost , thus delaying or preventing its thawing during summer, as well as inducing its formation. The amount of precipitation a wetland receives varies widely according to its area. Wetlands in Wales , Scotland , and western Ireland typically receive about 1,500 mm (59 in) per year. In some places in Southeast Asia , where heavy rains occur, they can receive up to 10,000 mm (390 in). In some drier regions, wetlands exist where as little as 180 mm (7.1 in) precipitation occurs each year. Temporal variation: Surface flow may occur in some segments, with subsurface flow in other segments. Wetlands vary widely due to local and regional differences in topography , hydrology , vegetation , and other factors, including human involvement. Other important factors include fertility, natural disturbance, competition, herbivory , burial and salinity. When peat accumulates, bogs and fens arise. The most important factor producing wetlands

490-540: A portion of the overall water cycle, which also includes atmospheric water (precipitation) and groundwater . Many wetlands are directly linked to groundwater and they can be a crucial regulator of both the quantity and quality of water found below the ground. Wetlands that have permeable substrates like limestone or occur in areas with highly variable and fluctuating water tables have especially important roles in groundwater replenishment or water recharge. Substrates that are porous allow water to filter down through

560-481: A protective barrier to coastal shoreline. Mangroves stabilize the coastal zone from the interior and will migrate with the shoreline to remain adjacent to the boundary of the water. The main conservation benefit these systems have against storms and storm surges is the ability to reduce the speed and height of waves and floodwaters. Amazon River basin The Amazon basin is the part of South America drained by

630-422: A strong influence on wetland water chemistry, particularly in coastal wetlands and in arid and semiarid regions with large precipitation deficits. Natural salinity is regulated by interactions between ground and surface water, which may be influenced by human activity. Carbon is the major nutrient cycled within wetlands. Most nutrients, such as sulfur , phosphorus , carbon , and nitrogen are found within

700-410: A unique kind of wetland where lush plant growth and slow decay of dead plants (under anoxic conditions) results in organic peat accumulating; bogs, fens, and mires are different names for peatlands. Variations of names for wetland systems: Some wetlands have localized names unique to a region such as the prairie potholes of North America's northern plain, pocosins , Carolina bays and baygalls of

770-566: A wedding venue. In 2012 WWT London Wetland Centre was voted Britain's Favourite Nature Reserve in the BBC Countryfile Magazine Awards. The site received 190,206 visitors during 2019. 51°28′43″N 0°13′59″W  /  51.4786°N 0.2331°W  / 51.4786; -0.2331 Wetland Wetlands exist on every continent , except Antarctica . The water in wetlands is either freshwater , brackish or saltwater . The main types of wetland are defined based on

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840-508: A wetland is "an ecosystem that arises when inundation by water produces soils dominated by anaerobic and aerobic processes, which, in turn, forces the biota, particularly rooted plants, to adapt to flooding". Sometimes a precise legal definition of a wetland is required. The definition used for regulation by the United States government is: 'The term "wetlands" means those areas that are inundated or saturated by surface or ground water at

910-422: A wetland system includes its plants ( flora ) and animals ( fauna ) and microbes (bacteria, fungi). The most important factor is the wetland's duration of flooding. Other important factors include fertility and salinity of the water or soils. The chemistry of water flowing into wetlands depends on the source of water, the geological material that it flows through and the nutrients discharged from organic matter in

980-403: A wetland) affects hydro-periods (temporal fluctuations in water levels) by controlling the water balance and water storage within a wetland. Landscape characteristics control wetland hydrology and water chemistry. The O 2 and CO 2 concentrations of water depend upon temperature , atmospheric pressure and mixing with the air (from winds or water flows). Water chemistry within wetlands

1050-558: A whole. To replace these wetland ecosystem services , enormous amounts of money would need to be spent on water purification plants, dams, levees, and other hard infrastructure, and many of the services are impossible to replace. Floodplains and closed-depression wetlands can provide the functions of storage reservoirs and flood protection. The wetland system of floodplains is formed from major rivers downstream from their headwaters . "The floodplains of major rivers act as natural storage reservoirs, enabling excess water to spread out over

1120-577: A wide area, which reduces its depth and speed. Wetlands close to the headwaters of streams and rivers can slow down rainwater runoff and spring snowmelt so that it does not run straight off the land into water courses. This can help prevent sudden, damaging floods downstream." Notable river systems that produce wide floodplains include the Nile River , the Niger river inland delta, the Zambezi River flood plain,

1190-623: Is one of the two longest rivers in the world . A team of scientists has claimed that the Amazon is longer than the Nile , but debate about its exact length continues. The Amazon system transports the largest volume of water of any river system, accounting for about 20% of the total water carried to the oceans by rivers. Some of the Amazon rainforests are deforested because of an increase in cattle ranches and soybean fields. The Amazon basin formerly flowed west to

1260-504: Is scarcely populated . There are scattered settlements inland, but most of the population lives in a few larger cities on the banks of the Amazon and other major rivers, such as in Iquitos – Loreto in Peru , Manaus - Amazonas State , and Belém , Pará . In many regions, the forest has been cleared for soya bean plantations and ranching (the most extensive non-forest use of the land); some of

1330-410: Is 1.5 million distributed. There are an estimated 100 uncontacted tribal groups. The largest organization fighting for the indigenous peoples in this area is COICA . It is a supra organization encompassing all indigenous rights organizations working in the Amazon basin area, and covers the people living in several countries. The river is the principal path of transportation for people and produce in

1400-440: Is determined by the pH , salinity , nutrients, conductivity , soil composition, hardness , and the sources of water. Water chemistry varies across landscapes and climatic regions. Wetlands are generally minerotrophic (waters contain dissolved materials from soils) with the exception of ombrotrophic bogs that are fed only by water from precipitation. Because bogs receive most of their water from precipitation and humidity from

1470-586: Is given by the number of different bird families that reside in these humid forests. An example of such would be the cotinga family, to which the Guianan cock-of-the-rock belong. Birds such as toucans , and hummingbirds are also found here. Macaws are famous for duck gathering by the hundreds along the clay cliffs of the Amazon River. In the western Amazon hundreds of macaws and other parrots descend to exposed river banks to consume clay on an almost daily basis,

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1540-412: Is hydrology, or flooding . The duration of flooding or prolonged soil saturation by groundwater determines whether the resulting wetland has aquatic, marsh or swamp vegetation . Other important factors include soil fertility, natural disturbance, competition, herbivory , burial, and salinity. When peat from dead plants accumulates, bogs and fens develop. Wetland hydrology is associated with

1610-619: Is land. The splash tetra is famous for laying its eggs on plants above water, keeping them moist by continuously splashing on them, the South American lungfish can survive underground in a mucous cocoon during the dry season, some small rivulid killifish can jump over land between water sources (sometimes moving relatively long distances, even uphill) and may deliberately jump onto land to escape aquatic predators, and an undescribed species of worm-like Phreatobius catfish lives in waterlogged leaf litter near (not in) streams. Some of

1680-509: Is produced for use in urban areas. Exploitation of bushmeat , particularly deer and turtles is common. Extensive deforestation , particularly in Brazil , is leading to the extinction of known and unknown species, reducing biological diversity and adversely impacting soil, water, and air quality. A final part of the deforestation process is the large-scale production of charcoal for industrial processes such as steel manufacturing. Soils within

1750-687: Is the center of diversity for Neotropical fishes . About 45% (more than 1,000 species) of the known Amazonian fish species are endemic to the basin. The remarkable species richness can in part be explained by the large differences between the various parts of the Amazon basin, resulting in many fish species that are endemic to small regions. For example, fauna in clearwater rivers differs from fauna in white and blackwater rivers , fauna in slow moving sections show distinct differences compared to that in rapids , fauna in small streams differ from that in major rivers, and fauna in shallow sections show distinct differences compared to that in deep parts. By far

1820-451: Is the only place in the world where both crocodiles and alligators coexist. The saltwater crocodile inhabits estuaries and mangroves. Snapping turtles also inhabit wetlands. Birds , particularly waterfowl and waders use wetlands extensively. Mammals of wetlands include numerous small and medium-sized species such as voles , bats , muskrats and platypus in addition to large herbivorous and apex predator species such as

1890-621: Is the second biggest peak of Yerupajá at 6,635 metres (21,768 ft). The Amazon River Basin occupies the entire central and eastern area of South America, lying to the east of the Andes mountain range and extending from the Guyana Plateau in the north to the Brazilian Plateau in the south. With a length of about 6,400 km (4,000 mi) before it drains into the Atlantic Ocean , it

1960-545: Is usually saturated with water". More precisely, wetlands are areas where "water covers the soil , or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season". A patch of land that develops pools of water after a rain storm would not necessarily be considered a "wetland", even though the land is wet. Wetlands have unique characteristics: they are generally distinguished from other water bodies or landforms based on their water level and on

2030-514: The Amazon River and its tributaries . The Amazon drainage basin covers an area of about 7,000,000 km (2,700,000 sq mi), or about 35.5 percent of the South American continent. It is located in the countries of Bolivia , Brazil , Colombia , Ecuador , Guyana , Peru , Suriname , and Venezuela , as well as the territory of French Guiana . Most of the basin is covered by

2100-511: The Amazon rainforest , also known as Amazonia . With a 5.5 million km (2.1 million sq mi) area of dense tropical forest , it is the largest rainforest in the world. The Amazon River begins in the Andes Mountains at the west of the basin with its main tributary the Marañón River and Apurimac River in Peru . The highest point in the watershed of the Amazon

2170-934: The Barn Elms Wetland Centre . The centre occupies more than 100 acres (40 hectares) of land which was formerly occupied by several small reservoirs. These were converted into a wide range of wetland features and habitats before the centre opened in May 2000. It was the first urban project of its kind in the United Kingdom . Many wild birds which have now made their home in the centre cannot be found anywhere else in London, and there are nationally significant numbers of gadwall and northern shoveler . Other wild birds include Eurasian bittern , northern pintail , northern lapwing , water rail , ring-necked parakeet , Eurasian sparrowhawk , sand martin , common kingfisher , little grebe and great crested grebe . The centre also holds

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2240-492: The Millennium Ecosystem Assessment from 2005. Methods exist for assessing wetland ecological health . These methods have contributed to wetland conservation by raising public awareness of the functions that wetlands can provide. Since 1971, work under an international treaty seeks to identify and protect " wetlands of international importance ." A simplified definition of wetland is "an area of land that

2310-533: The Pacific Ocean until the Andes formed, causing the basin to flow eastward towards the Atlantic Ocean. Politically the basin is divided into Peruvian Amazonia , Amazônia Legal of Brazil, the Amazon natural region of Colombia , Amazonas (Venezuelan state) , and parts of Bolivia and Ecuador . (km ) (km ) Plant growth is quite dense and its variety of animal inhabitants is comparatively high due to

2380-666: The Pantanal in South America, and the Sundarbans in the Ganges - Brahmaputra delta. Wetlands contribute many ecosystem services that benefit people. These include for example water purification , stabilization of shorelines, storm protection and flood control . In addition, wetlands also process and condense carbon (in processes called carbon fixation and sequestration ), and other nutrients and water pollutants . Wetlands can act as

2450-444: The atmosphere , their water usually has low mineral ionic composition. In contrast, wetlands fed by groundwater or tides have a higher concentration of dissolved nutrients and minerals. Fen peatlands receive water both from precipitation and ground water in varying amounts so their water chemistry ranges from acidic with low levels of dissolved minerals to alkaline with high accumulation of calcium and magnesium . Salinity has

2520-576: The beavers , coypu , swamp rabbit , Florida panther , jaguar , and moose . Wetlands attract many mammals due to abundant seeds, berries, and other vegetation as food for herbivores, as well as abundant populations of invertebrates, small reptiles and amphibians as prey for predators. Invertebrates of wetlands include aquatic insects such as dragonflies , aquatic bugs and beetles , midges, mosquitos , crustaceans such as crabs, crayfish, shrimps, microcrustaceans, mollusks like clams, mussels, snails and worms. Invertebrates comprise more than half of

2590-528: The largest strict freshwater fish in the world. The bull shark and common sawfish , which have been recorded far up the Amazon, may reach even greater sizes, but they are euryhaline and often seen in marine waters. In contrast to the giants, there are Amazonian fish from several families that are less than 2 cm (0.8 in) long. The smallest are likely the Leptophilypnion sleeper gobies, which do not surpass 1 cm (0.4 in) and are among

2660-459: The smallest fish in the world. The Amazon supports very large fisheries, including well-known species of large catfish (such as Brachyplatystoma , which perform long breeding migrations up the Amazon), arapaima and tambaqui , and is also home to many species that are important in the aquarium trade , such as the oscar , discus , angelfish , Corydoras catfish and neon tetra . Although

2730-468: The Amazon are Portuguese and Spanish . There are hundreds of native languages still spoken in the Amazon, most of which are critically endangered . Many tribal groups live in the Amazon Basin, often in relative isolation. It is estimated 400 or more tribal groups have lived in the Amazon Basin for hundreds of years with their own culture, language, and lifestyle. Today total population of Amazon basin

2800-644: The Amazon basin, has several other cavefish species. The deeper part of the major Amazonian rivers are always dark and a few species have adaptions similar to cavefish (reduced pigment and eyes). Among these are the knifefish Compsaraia and Orthosternarchus , some Cetopsis whale catfish (especially C. oliveirai ), some Xyliphius and Micromyzon banjo catfish, and the loricariid catfish Loricaria spinulifera , L. pumila , Peckoltia pankimpuju , Panaque bathyphilus and Panaqolus nix (these five also occur in "normal" forms of shallower waters). The perhaps most unusual habitat used by Amazonian fish

2870-421: The Amazon include Brazil nut , rubber tree and Assai palm . More than 1,400 species of mammals are found in the Amazon, the majority of which are species of bats and rodents . Its larger mammals include the jaguar , ocelot , capybara , puma and South American tapir . About 1,500 bird species inhabit the Amazon basin. The biodiversity of the Amazon and the sheer number of diverse bird species

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2940-399: The Amazon. Unlike temperate frogs which are mostly limited to habitats near the water, tropical frogs are most abundant in the trees and relatively few are found near bodies of water on the forest floor . The reason for this occurrence is quite simple: frogs must always keep their skin moist since almost half of their respiration is carried out through their skin. The high humidity of

3010-619: The Okavango River inland delta, the Kafue River flood plain, the Lake Bangweulu flood plain (Africa), Mississippi River (US), Amazon River (South America), Yangtze River (China), Danube River (Central Europe) and Murray-Darling River (Australia). Groundwater replenishment can be achieved for example by marsh , swamp , and subterranean karst and cave hydrological systems. The surface water visibly seen in wetlands only represents

3080-511: The Southeastern US, mallines of Argentina, Mediterranean seasonal ponds of Europe and California, turloughs of Ireland, billabongs of Australia, among many others. Wetlands are found throughout the world in different climates. Temperatures vary greatly depending on the location of the wetland. Many of the world's wetlands are in the temperate zones , midway between the North or South Poles and

3150-494: The US, the best known classifications are the Cowardin classification system and the hydrogeomorphic (HGM) classification system. The Cowardin system includes five main types of wetlands: marine (ocean-associated), estuarine (mixed ocean- and river-associated), riverine (within river channels), lacustrine (lake-associated) and palustrine (inland nontidal habitats). Peatlands are

3220-610: The United States' commercial fish and shellfish stocks depend solely on estuaries to survive. Amphibians such as frogs and salamanders need both terrestrial and aquatic habitats in which to reproduce and feed. Because amphibians often inhabit depressional wetlands like prairie potholes and Carolina bays, the connectivity among these isolated wetlands is an important control of regional populations. While tadpoles feed on algae, adult frogs forage on insects. Frogs are sometimes used as an indicator of ecosystem health because their thin skin permits absorption of nutrients and toxins from

3290-530: The dominant plants and the source of the water. For example, marshes are wetlands dominated by emergent herbaceous vegetation such as reeds , cattails and sedges . Swamps are dominated by woody vegetation such as trees and shrubs (although reed swamps in Europe are dominated by reeds, not trees). Mangrove forest are wetlands with mangroves , halophytic woody plants that have evolved to tolerate salty water . Examples of wetlands classified by

3360-622: The equator. In these zones, summers are warm and winters are cold, but temperatures are not extreme. In subtropical zone wetlands, such as along the Gulf of Mexico , average temperatures might be 11 °C (52 °F). Wetlands in the tropics are subjected to much higher temperatures for a large portion of the year. Temperatures for wetlands on the Arabian Peninsula can exceed 50 °C (122 °F) and these habitats would therefore be subject to rapid evaporation. In northeastern Siberia , which has

3430-498: The exception being rainy days. The green anaconda inhabits the shallow waters of the Amazon and the emerald tree boa and boa constrictor live in the Amazonian tree tops. Many reptile species are illegally collected and exported for the international pet trade. Live animals are the fourth largest commodity in the smuggling industry after drugs, diamonds and weapons. More than 1,500 species of amphibians swim and are found in

3500-494: The following areas: According to the Ramsar Convention: The economic worth of the ecosystem services provided to society by intact, naturally functioning wetlands is frequently much greater than the perceived benefits of converting them to 'more valuable' intensive land use – particularly as the profits from unsustainable use often go to relatively few individuals or corporations, rather than being shared by society as

3570-482: The heavy rainfall and the dense and extensive evergreen and coniferous forests . Little sunlight reaches the ground due to the dense roof of canopy by plants. The ground remains dark and damp and only shade-tolerant vegetation will grow here. Orchids and bromeliads exploit trees and other plants to get closer to the sunlight. They grow hanging onto the branches or tree trunks with aerial roots , not as parasites but as epiphytes . Species of tropical trees native to

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3640-443: The inhabitants harvest wild rubber latex , and Brazilian nuts . This is a form of extractive farms, where the trees are not cut down. These are relatively sustainable operations in contrast to lumbering or agriculture dependent on clearing the rainforest. The people live in thatched houses shaped liked beehives. They also build apartment-like houses called " Maloca ", with a steeply slanting roof. The most widely spoken languages in

3710-464: The interface between truly terrestrial ecosystems and aquatic systems, making them inherently different from each other, yet highly dependent on both." In environmental decision-making, there are subsets of definitions that are agreed upon to make regulatory and policy decisions. Under the Ramsar international wetland conservation treaty , wetlands are defined as follows: An ecological definition of

3780-462: The known animal species in wetlands, and are considered the primary food web link between plants and higher animals (such as fish and birds). Depending on a wetland's geographic and topographic location, the functions it performs can support multiple ecosystem services , values, or benefits. United Nations Millennium Ecosystem Assessment and Ramsar Convention described wetlands as a whole to be of biosphere significance and societal importance in

3850-586: The major fish groups of the Amazon basin include: More than 90% of the animal species in the Amazon are insects , of which about 40% are beetles (Coleoptera constituting almost 25% of all known types of animal life-forms.) Whereas all of Europe has some 321 butterfly species, the Manú National Park in Peru (4000 hectare-survey) has 2300 species, while Tambopata National Reserve (5500 hectare-survey) has at least 1231 species. The Amazon River basin has

3920-482: The most diverse orders in the Amazon are Characiformes (43% of total fish species in the Amazon) and Siluriformes (39%), but other groups with many species include Cichlidae (6%) and Gymnotiformes (3%). In addition to major differences in behavior and ecology, Amazonian fish vary extensively in form and size. The largest, the arapaima and piraiba can reach 3 m (9.8 ft) or more in length and up to 200 kg (440 lb) in weight, making them some of

3990-832: The plants and animals controlled by the wetland hydrology are often additional components of the definitions. Wetlands can be tidal (inundated by tides) or non-tidal. The water in wetlands is either freshwater , brackish , saline , or alkaline . There are four main kinds of wetlands – marsh , swamp , bog , and fen (bogs and fens being types of peatlands or mires ). Some experts also recognize wet meadows and aquatic ecosystems as additional wetland types. Sub-types include mangrove forests , carrs , pocosins , floodplains , peatlands, vernal pools , sinks , and many others. The following three groups are used within Australia to classify wetland by type: Marine and coastal zone wetlands, inland wetlands and human-made wetlands. In

4060-449: The rainforest and frequent rainstorms gives tropical frogs infinitely more freedom to move into the trees and escape the many predators of rainforest waters. The differences between temperate and tropical frogs extend beyond their habitat. About 2500 fish species are known from the Amazon basin and it is estimated that more than 1,000 additional undescribed species exist. This is more than any other river basin on Earth, and Amazonia

4130-584: The region are generally shallow and cannot be used for more than a few seasons without the addition of imported fertilizers and chemicals. "Over past 20 years (2021), the Brazilian Amazon emitted 13% more CO 2 than it absorbed". "Amazon biodiversity also plays a critical role as part of global systems, influencing the global carbon cycle and thus climate change , as well as hemispheric hydrological systems, serving as an important anchor for South American climate and rainfall. It also produces 20% oxygen of

4200-615: The regions, with transport ranging from balsa rafts and dugout canoes to hand built wooden river craft and modern steel hulled craft. Seasonal floods excavate and redistribute nutrient-rich silt onto beaches and islands, enabling dry-season riverside agriculture of rice, beans, and corn on the river's shoreline without the addition of fertilizer, with additional slash and burn agriculture on higher floodplains. Fishing provides additional food year-round, and free-range chickens need little or no food beyond what they can forage locally. Charcoal made largely from forest and shoreline deadfall

4270-429: The soil and underlying rock into aquifers which are the source of much of the world's drinking water . Wetlands can also act as recharge areas when the surrounding water table is low and as a discharge zone when it is high. Mangroves , coral reefs , salt marsh can help with shoreline stabilization and storm protection. Tidal and inter-tidal wetland systems protect and stabilize coastal zones. Coral reefs provide

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4340-537: The soil of wetlands. Anaerobic and aerobic respiration in the soil influences the nutrient cycling of carbon, hydrogen, oxygen, and nitrogen, and the solubility of phosphorus thus contributing to the chemical variations in its water. Wetlands with low pH and saline conductivity may reflect the presence of acid sulfates and wetlands with average salinity levels can be heavily influenced by calcium or magnesium. Biogeochemical processes in wetlands are determined by soils with low redox potential. The life forms of

4410-412: The soils and plants at higher elevations. Plants and animals may vary within a wetland seasonally or in response to flood regimes. There are four main groups of hydrophytes that are found in wetland systems throughout the world. Submerged wetland vegetation can grow in saline and fresh-water conditions. Some species have underwater flowers, while others have long stems to allow the flowers to reach

4480-461: The sources of water include tidal wetlands , where the water source is ocean tides ); estuaries , water source is mixed tidal and river waters; floodplains , water source is excess water from overflowed rivers or lakes; and bogs and vernal ponds , water source is rainfall or meltwater . The world's largest wetlands include the Amazon River basin , the West Siberian Plain ,

4550-406: The spatial and temporal dispersion, flow, and physio-chemical attributes of surface and ground waters. Sources of hydrological flows into wetlands are predominantly precipitation , surface water (saltwater or freshwater), and groundwater. Water flows out of wetlands by evapotranspiration , surface flows and tides , and subsurface water outflow. Hydrodynamics (the movement of water through and from

4620-661: The surface of the water. When trees and shrubs comprise much of the plant cover in saturated soils, those areas in most cases are called swamps . The upland boundary of swamps is determined partly by water levels. This can be affected by dams Some swamps can be dominated by a single species, such as silver maple swamps around the Great Lakes . Others, like those of the Amazon basin , have large numbers of different tree species. Other examples include cypress ( Taxodium ) and mangrove swamps. Many species of fish are highly dependent on wetland ecosystems. Seventy-five percent of

4690-490: The surface. Submerged species provide a food source for native fauna, habitat for invertebrates, and also possess filtration capabilities. Examples include seagrasses and eelgrass . Floating water plants or floating vegetation are usually small, like those in the Lemnoideae subfamily (duckweeds). Emergent vegetation like the cattails ( Typha spp.), sedges ( Carex spp.) and arrow arum ( Peltandra virginica ) rise above

4760-457: The surrounding environment resulting in increased extinction rates in unfavorable and polluted environmental conditions. Reptiles such as snakes , lizards , turtles , alligators and crocodiles are common in wetlands of some regions. In freshwater wetlands of the Southeastern US, alligators are common and a freshwater species of crocodile occurs in South Florida. The Florida Everglades

4830-454: The true danger they represent often is greatly exaggerated, the Amazon basin is home to several feared fish species such as piranhas (including the famous red-bellied ), electric eel , river stingrays and candiru . Several cavefish species in the genus Phreatobius are found in the Amazon, as is the cave-dwelling Astroblepus pholeter in the far western part of the basin (Andean region). The Tocantins basin, arguably not part of

4900-440: The types of plants that live within them. Specifically, wetlands are characterized as having a water table that stands at or near the land surface for a long enough period each year to support aquatic plants . A more concise definition is a community composed of hydric soil and hydrophytes . Wetlands have also been described as ecotones , providing a transition between dry land and water bodies. Wetlands exist "...at

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