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69-467: Mill Dam is a wetland in western Shapinsay , in Orkney, Scotland . This water body was not shown on the 1840 survey map of the island, since it is a man-made creation from a damming in the 1880s. Mill Dam is fed by a stream flowing from the north that rises on the western lobe of Shapinsay. The pH levels of the outflow stream of Mill Dam are moderately alkaline , in the range of 9.18. The Mill Dam wetland

138-711: 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

207-402: 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

276-418: A negative flux implies flux from air into the soil. Negative N 2 O fluxes are common and are caused by consumption by the soil. Wetlands counteract the sinking action that normally occurs with soil because of the high water table. The level of the water table represents the boundary between anaerobic methane production and aerobic methane consumption. When the water table is low, the methane generated within

345-421: A pathway varies per wetland based on the type of soil and vegetation. For example, in peatlands, the mass amount of dead, but not decaying, organic matter results in relatively slow diffusion of methane through the soil. Additionally, because methane can travel more quickly through soil than water, diffusion plays a much bigger role in wetlands with drier, more loosely compacted soil. Plant aerenchyma refers to

414-1248: 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

483-540: 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

552-462: A protected area in Scotland is a stub . You can help Misplaced Pages by expanding it . This Orkney location article is a stub . You can help Misplaced Pages by expanding it . 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 the dominant plants and the source of

621-518: 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. Greenhouse gas emissions from wetlands Greenhouse gas emissions from wetlands of concern consist primarily of methane and nitrous oxide emissions. Wetlands are

690-477: A significant source of methane emissions and some are also emitters of nitrous oxide . Wetlands account for approximately 20–30% of atmospheric methane through emissions from soils and plants. Nitrous oxide is a greenhouse gas with a global warming potential 300 times that of carbon dioxide and is the dominant ozone -depleting substance emitted in the 21st century. Excess nutrients mainly from anthropogenic sources have been shown to significantly increase

759-422: 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

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828-410: 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

897-508: 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

966-422: 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

1035-403: 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

1104-558: 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

1173-577: 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,

1242-519: Is a significant bird habitat and is owned and managed by the Royal Society for the Protection of Birds . It has been designated an Important Bird Area (IBA) by BirdLife International because it supports resident northern pintails and wintering whooper swans . 59°2′31″N 2°53′46″W  /  59.04194°N 2.89611°W  / 59.04194; -2.89611 This article related to

1311-440: 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

1380-495: Is directly related to methane emissions in wetlands. The magnitude of methane emission from a wetland are usually measured using eddy covariance , gradient or chamber flux techniques, and depends upon several factors, including water table , comparative ratios of methanogenic bacteria to methanotrophic bacteria, transport mechanisms, temperature, substrate type, plant life, and climate. These factors work together to effect and control methane flux in wetlands. Overall

1449-412: 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

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1518-605: Is the dominant ozone -depleting substance emitted in the 21st century. Wetlands can also act as a sink for greenhouse gases. Characteristics of wetland classes can assist to inform on magnitude of methane emissions. However, wetland classes have displayed high variability in methane emissions spatially and temporally. Wetlands are often classified by landscape position, vegetation, and hydrologic regime. Wetland classes include marshes , swamps , bogs , fens , peatlands , muskegs , prairie pothole (landform) , and pocosins . Depending on their characteristics, some wetlands are

1587-451: 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

1656-545: 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

1725-492: 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

1794-666: 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

1863-444: 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

1932-576: 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

2001-485: The largest natural source of atmospheric methane in the world, and are therefore a major area of concern with respect to climate change . Wetlands account for approximately 20–30% of atmospheric methane through emissions from soils and plants, and contribute an approximate average of 161 Tg of methane to the atmosphere per year. Wetlands are characterized by water-logged soils and distinctive communities of plant and animal species that have adapted to

2070-405: The N 2 O fluxes from wetland soils through denitrification and nitrification processes (see table below). A study in the intertidal region of a New England salt marsh showed that excess levels of nutrients might increase N 2 O emissions rather than sequester them. Data on nitrous oxide fluxes from wetlands in the southern hemisphere are lacking, as are ecosystem-based studies including

2139-619: 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

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2208-511: 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

2277-494: 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

2346-610: 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

2415-428: The amount of carbon dioxide in the surrounding atmosphere, which would in turn decrease the addition of methane into the atmosphere, as shown by an 80% decrease in methane flux in areas of doubled carbon dioxide levels. Humans often drain wetlands in the name of development, housing, and agriculture. By draining wetlands, the water table is thus lowered, increasing consumption of methane by the methanotrophic bacteria in

2484-418: The availability of oxygen , soil temperature, and the composition of the soil. A warmer, more anaerobic environment with soil rich in organic matter would allow for more efficient methanogenesis. Some wetlands are a significant source of methane emissions and some are also emitters of nitrous oxide . Nitrous oxide is a greenhouse gas with a global warming potential 300 times that of carbon dioxide and

2553-458: The carbon needed for methane producing processes in wetlands but can affect its transport as well. Fermentation is a process used by certain kinds of microorganisms to break down essential nutrients . In a process called acetoclastic methanogenesis , microorganisms from the classification domain archaea produce methane by fermenting acetate and H 2 -CO 2 into methane and carbon dioxide . H 3 C-COOH → CH 4 + CO 2 Depending on

2622-491: The constant presence of water . This high level of water saturation creates conditions conducive to methane production. Most methanogenesis , or methane production, occurs in oxygen-poor environments. Because the microbes that live in warm, moist environments consume oxygen more rapidly than it can diffuse in from the atmosphere, wetlands are the ideal anaerobic environments for fermentation as well as methanogen activity. However, levels of methanogenesis fluctuates due to

2691-453: The day from plants that use pressurized ventilation. Temperature is also an important factor to consider as the environmental temperature—and temperature of the soil in particular—affects the metabolic rate of production or consumption by bacteria. Additionally, because methane fluxes occur annually with the seasons, evidence is provided that suggests that the temperature changing coupled with water table level work together to cause and control

2760-480: The effects of water table and temperature. Net ecosystem production (NEP) and climate changes are the all encompassing factors that have been shown to have a direct relationship with methane emissions from wetlands. In wetlands with high water tables, NEP has been shown to increase and decrease with methane emissions, most likely due to the fact that both NEP and methane emissions flux with substrate availability and soil composition. In wetlands with lower water tables,

2829-622: 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

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2898-494: 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

2967-464: 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

3036-462: 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

3105-412: The main determinant of net flux of methane into the atmosphere is the ratio of methane produced by methanogenic bacteria that makes it to the surface relative to the amount of methane that is oxidized by methanotrophic bacteria before reaching the atmosphere. This ratio is in turn affected by the other controlling factors of methane in the environment. Additionally, pathways of methane emission affect how

3174-424: The methane travels into the atmosphere and thus have an equal effect on methane flux in wetlands. The first controlling factor to consider is the level of the water table . Not only does pool and water table location determine the areas where methane production or oxidation may take place, but it also determines how quickly methane can diffuse into the air. When traveling through water, the methane molecules run into

3243-420: The methane up through the soil so quickly that it does not have time to be consumed by the methanotrophic organisms in the soil. With this release of gas, the level of soil then falls once more. Ebullition in wetlands can be recorded by delicate sensors, called piezometers , that can detect the presence of pressure pockets within the soil. Hydraulic heads are also used to detect the subtle rising and falling of

3312-483: The movement of oxygen in and out of the soil can increase the oxidation of methane and the inhibition of methanogenesis, nulling the relationship between methane emission and NEP because methane production becomes dependent upon factors deep within the soil. A changing climate affects many factors within the ecosystem, including water table, temperature, and plant composition within the wetland—all factors that affect methane emissions. However, climate change can also affect

3381-495: The nutrients available to the bacteria as well as the acidity . Plant leachates such as phenolic compounds from Sphagnum can also interact with soil characteristics to influence methane production and consumption. A constant availability of cellulose and a soil pH of about 6.0 have been determined to provide optimum conditions for methane production and consumption; however, substrate quality can be overridden by other factors. Soil pH and composition must still be compared to

3450-832: 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

3519-411: The plants to their roots. Ebullition refers to the sudden release of bubbles of methane into the air. These bubbles occur as a result of methane building up over time in the soil, forming pockets of methane gas. As these pockets of trapped methane grow in size, the level of the soil will slowly rise up as well. This phenomenon continues until so much pressure builds up that the bubble "pops," transporting

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3588-568: The quickly moving water molecules and thus take a longer time to reach the surface. Travel through soil, however, is much easier and results in easier diffusion into the atmosphere. This theory of movement is supported by observations made in wetlands where significant fluxes of methane occurred after a drop in the water table due to drought . If the water table is at or above the surface, then methane transport begins to take place primarily through ebullition and vascular or pressurized plant mediated transport, with high levels of emission occurring during

3657-455: The role of dominant organisms that alter sediment biogeochemistry. Aquatic invertebrates produce ecologically-relevant nitrous oxide emissions due to ingestion of denitrifying bacteria that live within the subtidal sediment and water column and thus may also be influencing nitrous oxide production within some wetlands. (μmol N 2 O m h ) The flux rates are shown as hourly rates per unit area. A positive flux implies flux from soil into air;

3726-430: The seasonal cycles. The composition of soil and substrate availability change the nutrients available for methanogenic and methanotrophic bacteria, and thus directly affects the rate of methane production and consumption. For example, wetlands soils with high levels of acetate or hydrogen and carbon dioxide are conducive to methane production. Additionally, the type of plant life and amount of plant decomposition affects

3795-429: 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

3864-466: The soil as a result of pressure build up and release. Using piezometers and hydraulic heads, a study was done in northern United States peatlands to determine the significance of ebullition as a source of methane. Not only was it determined that ebullition is in fact a significant source of methane emissions in northern United States peatlands, but it was also observed that there was an increase in pressure after significant rainfall, suggesting that rainfall

3933-537: 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

4002-409: The soil. However, as a result of draining, water saturated ditches develop, which due to the warm, moist environment, end up emitting a large amount of methane. Therefore, the actual effect on methane emission strongly ends up depending on several factors. If the drains are not spaced far enough apart, then saturated ditches will form, creating mini wetland environments. Additionally, if the water table

4071-412: 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

4140-515: 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 ,

4209-406: 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

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4278-709: 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

4347-490: 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

4416-457: 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

4485-440: 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

4554-410: The vessel-like transport tubes within the tissues of certain kinds of plants. Plants with aerenchyma possess porous tissue that allows for direct travel of gases to and from the plant roots. Methane can travel directly up from the soil into the atmosphere using this transport system. The direct "shunt" created by the aerenchyma allows for methane to bypass oxidation by oxygen that is also transported by

4623-490: 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

4692-431: The wetland and type of archaea, hydrogenotrophic methanogenesis, another process that yields methane, can also occur. This process occurs as a result of archaea oxidizing hydrogen with carbon dioxide to yield methane and water. 4H 2 + CO 2 → CH 4 + 2H 2 O Diffusion through the profile refers to the movement of methane up through soil and bodies of water to reach the atmosphere. The importance of diffusion as

4761-499: The wetland soil has to come up through the soil and get past a deeper layer of methanotrophic bacteria , thereby reducing emission. Methane transport by vascular plants can bypass this aerobic layer, thus increasing emission. Once produced, methane can reach the atmosphere via three main pathways: molecular diffusion , transport through plant aerenchyma , and ebullition. Primary productivity fuels methane emissions both directly and indirectly because plants not only provide much of

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