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Wetland

March 25, 2023

For other uses, see Wetland (disambiguation).

Wetlands, or simply a wetland, is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils.[1] The primary factor that distinguishes wetlands from terrestrial land forms or water bodies is the characteristic vegetation of aquatic plants, adapted to the unique anoxic hydric soils.[2] Wetlands are considered among the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal species. Methods for assessing wetland functions, wetland ecological health, and general wetland condition have been developed for many regions of the world. These methods have contributed to wetland conservation partly by raising public awareness of the functions some wetlands provide.[3]

Wetlands come in different sizes, types, and locations. Clockwise from top left: Upland vs. wetland vs. lacustrine zones; Freshwater swamp forest in Bangladesh; A freshwater cattail (Typha) marsh that develops with standing water and high soil fertility; Peat bogs are freshwater wetlands that develop in areas with standing water and low soil fertility.

Wetlands occur naturally on every continent.[4] The water in wetlands is either freshwater, brackish or saltwater.[2] The main wetland types are classified based on the dominant plants and/or the source of the water. For example, marshes are wetlands dominated by emergent vegetation such as reeds, cattails and sedges; swamps are ones dominated by woody vegetation such as trees and shrubs (although reed swamps in Europe are dominated by reeds, not trees). Examples of wetlands classified by their sources of water include tidal wetlands (oceanic tides), estuaries (mixed tidal and river waters), floodplains (excess water from overflowed rivers or lakes), springs, seeps and fens (groundwater discharge out onto the surface), and bogs and vernal ponds (rainfall or meltwater).[1][5] Some wetlands have multiple types of plants and are fed by multiple sources of water, making them difficult to classify. The world's largest wetlands include the Amazon River basin, the West Siberian Plain,[6] the Pantanal in South America,[7] and the Sundarbans in the Ganges-Brahmaputra delta.[8]

Wetlands contribute a number of functions that benefit people. These are called ecosystem services and include water purification, groundwater replenishment, stabilization of shorelines and storm protection, water storage and flood control, processing of carbon (carbon fixation, decomposition and sequestration), other nutrients and pollutants, and support of plants and animals.[9] Wetlands are reservoirs of biodiversity and provide wetland products. According to the UN Millennium Ecosystem Assessment, wetlands are more affected by environmental degradation than any other ecosystem on Earth.[10] Wetlands can be important sources and sinks of carbon, depending on the specific wetland, and thus will play an important role in climate change and need to be considered in attempts to mitigate climate change. However, some wetlands are a significant source of methane emissions and some are also emitters of nitrous oxide.[11][12] Constructed wetlands are designed and built to treat municipal and industrial wastewater as well as to divert stormwater runoff. Constructed wetlands may also play a role in water-sensitive urban design.

Definitions and terminology

 
Marshlands are often noted within wetlands, as seen here in the New Jersey Meadowlands at Lyndhurst, New Jersey, U.S.

Technical definitions

A simplified definition of wetland is "an area of land that is usually saturated with water".[13] 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".[14] 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 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.[15][16]

A more concise definition is a community composed of hydric soil and hydrophytes.[1]

Wetlands have also been described as ecotones, providing a transition between dry land and water bodies.[17] Wetlands exist "...at the interface between truly terrestrial ecosystems and aquatic systems, making them inherently different from each other, yet highly dependent on both."[18]

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:[19]

  • Article 1.1: "...wetlands are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters."
  • Article 2.1: "[Wetlands] may incorporate riparian and coastal zones adjacent to the wetlands, and islands or bodies of marine water deeper than six meters at low tide lying within the wetlands."

An ecological definition of 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".[1]

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 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.'[20]

For each of these definitions and others, regardless of the purpose, hydrology is emphasized (shallow waters, water-logged soils). The soil characteristics and the plants and animals controlled by the wetland hydrology are often additional components of the definitions.[21]

Types

 
Sunrise at Viru Bog, Estonia
Main article: Classification of wetlands

Wetlands can be tidal (inundated by tides) or non-tidal.[22] The water in wetlands is either freshwater, brackish, or saltwater.[2] 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.[1] Sub-types include mangrove forests, carrs, pocosins, floodplains,[1] peatlands, vernal pools, sinks, and many others.[23]

The following three groups are used within Australia to classify wetland by type: Marine and coastal zone wetlands, inland wetlands and human-made wetlands.[24] In the US, the best known classifications are the Cowardin classification system[25] 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

Peatlands are 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.

Wetland names

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[26][27] of the Southeastern US, mallines of Argentina, Mediterranean seasonal ponds of Europe and California, turloughs of Ireland, billabongs of Australia, among many others.

Locations

By temperature zone

 
Wetlands contrast the hot, arid landscape around Middle Spring, Fish Springs National Wildlife Refuge, Utah

Wetlands are found throughout the world in different climates.[14] 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 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 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.[28]

By precipitation amount

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.[citation needed] In some places in Southeast Asia, where heavy rains occur, they can receive up to 10,000 mm (390 in).[citation needed] In some drier regions, wetlands exist where as little as 180 mm (7.1 in) precipitation occurs each year.[citation needed]

Temporal variation:[29]

Surface flow may occur in some segments, with subsurface flow in other segments.

Processes

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.[1] When peat accumulates, bogs and fens arise.

Hydrology

The most important factor producing wetlands 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.[1] When peat from dead plants accumulates, bogs and fens develop.

Wetland hydrology is associated with 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 a wetland) affects hydro-periods (temporal fluctuations in water levels) by controlling the water balance and water storage within a wetland.[30]

Landscape characteristics control wetland hydrology and water chemistry. The O2 and CO2 concentrations of water depend on temperature, atmospheric pressure and mixing with the air (from winds or water flows). Water chemistry within wetlands 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 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.[31]

Role of salinity

Salinity has a strong influence on wetland water chemistry, particularly in coastal wetlands[1][32] 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.[33]

Soil

Carbon is the major nutrient cycled within wetlands. Most nutrients, such as sulfur, phosphorus, carbon, and nitrogen are found within the soil of wetlands. Anaerobic and aerobic respiration in the soil influences the nutrient cycling of carbon, hydrogen, oxygen, and nitrogen,[34] and the solubility of phosphorus[35] thus contributing to the chemical variations in its water. Wetlands with low pH and saline conductivity may reflect the presence of acid sulfates[36] 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.[37] Wetland soils are identified by redoxymorphic mottles (often from iron oxide rust) or low chroma intensity, as determined by the Munsell Color System.

Water chemistry

Due to the low dissolved oxygen (DO) content, and relatively low nutrient balance of wetland environments, most wetlands are very susceptible to alterations in water chemistry. Key factors that are assessed to determine water quality include:

These chemical factors can be used to quantify wetland disturbances, and often provide information as to whether a wetland is fed by precipitation, surface water or groundwater, due to the different ion characteristics of the different water sources.[38] Wetlands are adept at impacting the water chemistry of streams or water bodies that interact with them, and can process ions that result from water pollution such as acid mine drainage or urban runoff.,[39][40]

Biota

The biota of a wetland system includes its plants (flora) and animals (fauna) and microbes (bacteria, fungi). The most important factor affecting the biota is the hydroperiod, or the duration of flooding.[1] 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[41] and the nutrients discharged from organic matter in the soils and plants at higher elevations.[42] Biota may vary within a wetland seasonally or in response to flood regimes.

 
Humid wetland in Pennsylvania before a rain.

Flora

 
Bud of water lotus (Nelumbo nucifera), an aquatic plant.

There are four main groups of hydrophytes that are found in wetland systems throughout the world.[43]

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 the surface.[44] 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 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.[1] The upland boundary of swamps is determined partly by water levels. This can be affected by dams[45] Some swamps can be dominated by a single species, such as silver maple swamps around the Great Lakes.[46] Others, like those of the Amazon basin, have large numbers of different tree species.[47] Other examples include cypress (Taxodium) and mangrove swamps.

Fauna

 
Many species of frogs live in wetlands, while others visit them each year to lay eggs.
 
Snapping turtles are one of the many kinds of turtles found in wetlands.

Many species of fish are highly dependent on wetland ecosystems.[48][49] Seventy-five percent of the United States' commercial fish and shellfish stocks depend solely on estuaries to survive.[50] Tropical fish species need mangroves for critical hatchery and nursery grounds and the coral reef system for food.

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.[51] 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 the surrounding environment resulting in increased extinction rates in unfavorable and polluted environmental conditions.[52]

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 is the only place in the world where both crocodiles and alligators coexist.[53] The saltwater crocodile inhabits estuaries and mangroves and can be seen along the Eastern coastline of Australia.[54] Snapping turtles are one of the many kinds of turtles found in wetlands.[55]

Birds, particularly waterfowl and wading birds, use wetlands extensively.[56]

Mammals of wetlands[57] include numerous small and medium-sized species such as voles, bats,[58] muskrats[59] and platypus in addition to large herbivorous and apex predator species such as the beaver,[60] coypu, swamp rabbit, Florida panther,[61] 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.[62]

Invertebrates of wetlands include aquatic insects (such as dragonflies, aquatic bugs and beetles, midges, mosquitoes), crustaceans (such as crabs, crayfish, shrimps, microcrustaceans), mollusks (such as clams, mussels, snails), and worms (such as polychaetes, oligochaetes, leeches), among others. Invertebrates comprise more than half of the known animal species in wetlands, and are considered the primary food web link between plants and higher animals (such as fish and birds).[63] The low oxygen conditions in wetland water and their frequent flooding and drying (daily in tidal wetlands, seasonally in temporary ponds and floodplains) prevent many invertebrates from inhabiting wetlands, and thus the invertebrate fauna of wetlands is often less diverse than some other kinds of habitat (such as streams, coral reefs, and forests). Some wetland invertebrates thrive in habitats that lack predatory fish. Many insects only inhabit wetlands as aquatic immatures (nymphs, larvae) and the flying adults inhabit upland habitats, returning to the wetlands to lay eggs. For instance, a common hoverfly Syritta pipiens inhabits wetlands as larvae (maggots), living in wet, rotting organic matter; these insects then visit terrestrial flowers as adult flies.

Algae

Algae are diverse plant-like organisms that can vary in size, color, and shape. Algae occur naturally in habitats such as inland lakes, inter-tidal zones, and damp soil and provide a food source for many animals, including some invertebrates, fish, turtles, and frogs. There are several groups of algae:

  • Phytoplankton are microscopic, free-floating algae. These algae are so tiny that on average, 50 of these lined up end-to-end would only measure one millimeter. Phytoplankton are the basis of the food web in many water bodies being responsible for much of the primary production using photosynthesis to fix carbon.Filamentous algae are long strands of algal cells that can form floating mats. Periphyton (or epiphyton) are algae that grow as surface biofilms on plants, wood, and other substrates.[64]
  • Chara and Nitella algae are upright algae that look like a submerged plants with roots.[65]

Disturbances and human impacts

See also: Human impacts on the environment

Wetlands, the functions and services they provide as well as their flora and fauna, can be affected by several types of disturbances.[66] The disturbances (sometimes termed stressors or alterations) can be human-associated or natural, direct or indirect, reversible or not, and isolated or cumulative. Disturbances exceed the levels or patterns normally found within wetlands of a particular class in a particular region. Predominant disturbances of wetlands include:[67][68]

Disturbances can be further categorized as follows:

  • Minor disturbance: Stress that maintains ecosystem integrity.[69]
  • Moderate disturbance: Ecosystem integrity is damaged but can recover in time without assistance.[69]
  • Impairment or severe disturbance: Human intervention may be needed in order for ecosystem to recover.[69]

Just a few of the many sources of these disturbances include:[70]

They can be manifested partly as:

Biodiversity loss occurs in wetland systems through land use changes, habitat destruction, pollution, exploitation of resources, and invasive species. Vulnerable, threatened, and endangered species include 17% of waterfowl, 38% of fresh-water dependent mammals, 33% of freshwater fish, 26% of freshwater amphibians, 72% of freshwater turtles, 86% of marine turtles, 43% of crocodilians and 27% of coral reef-building species. Introduced aquatic plants in different wetland systems can have large impacts. The introduction of water hyacinth, a native plant of South America into Lake Victoria in East Africa as well as duckweed into non-native areas of Queensland, Australia, have overtaken entire wetland systems overwhelming the habitats and reducing the diversity of native plants and animals. This is largely due to the phenomenal growth rates of the plants and their ability to float and grow across the entire surface of the water.

Conversion to dry land

Due to their productivity, wetlands are often converted into dry land with dykes and drains and used for agricultural purposes. The construction of dykes, and dams, has negative consequences for individual wetlands and entire watersheds.[1]: 497  Their proximity to lakes and rivers means that they are often developed for human settlement.[72] Once settlements are constructed and protected by dykes, the settlements then become vulnerable to land subsidence and ever increasing risk of flooding.[1]: 497  The Mississippi River Delta around New Orleans, Louisiana is a well-known example;[73] the Danube Delta in Europe is another.[74]

Ecosystem services

Further information: Ecosystem service

Depending on a wetland's geographic and topographic location,[75] 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 the following areas:[76]

According to the Ramsar Convention:[citation needed]

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 a whole.

Unless otherwise cited, ecosystem services information is based on the following series of references.[50]

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.

Storage reservoirs and flood protection

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 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 doesn't run straight off the land into water courses. This can help prevent sudden, damaging floods downstream."[50] Notable river systems that produce wide floodplains include the Nile River, the Niger river inland delta, the Zambezi River flood plain, the Okavango River inland delta, the Kafue River flood plain, the Lake Bangweulu flood plain (Africa), Mississippi River (USA), Amazon River (South America), Yangtze River (China), Danube River (Central Europe) and Murray-Darling River (Australia).

Drainage of floodplains or development activities that narrow floodplain corridors (such as the construction of levees) reduces the ability of coupled river-floodplain systems to control flood damage. That is because modified and less expansive systems must still manage the same amount of precipitation, causing flood peaks to be higher or deeper and floodwaters to travel faster.

Water management engineering developments in the past century have degraded floodplain wetlands through the construction of artificial embankments such as dykes, bunds, levees, weirs, barrages and dams. All concentrate water into a main channel and waters that historically spread slowly over a large, shallow area are concentrated. Loss of wetland floodplains results in more severe and damaging flooding. Catastrophic human impact in the Mississippi River floodplains was seen in death of several hundred individuals during a levee breach in New Orleans caused by Hurricane Katrina. Human-made embankments along the Yangtze River floodplains have caused the main channel of the river to become prone to more frequent and damaging flooding.[77] Some of these events include the loss of riparian vegetation, a 30% loss of the vegetation cover throughout the river's basin, a doubling of the percentage of the land affected by soil erosion, and a reduction in reservoir capacity through siltation build-up in floodplain lakes.[50]

Groundwater replenishment

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 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.[78] Substrates that are porous allow water to filter down through 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. Karst (cave) systems are a unique example of this system and can be a connection of underground rivers influenced by rain and other forms of precipitation to the surface.

Shoreline stabilization and storm protection

Main article: Integrated coastal zone management

Mangroves, coral reefs, salt marsh can help with shoreline stabilization and storm protection.

Tidal and inter-tidal wetland systems protect and stabilize coastal zones.[79] Coral reefs provide 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.

The number of people who live and work near the coast is expected to grow immensely over the next fifty years. From an estimated 200 million people that currently live in low-lying coastal regions, the development of urban coastal centers is projected to increase the population by fivefold within 50 years.[80] The United Kingdom has begun the concept of managed coastal realignment. This management technique provides shoreline protection through restoration of natural wetlands rather than through applied engineering. In East Asia, reclamation of coastal wetlands has resulted in widespread transformation of the coastal zone, and up to 65% of coastal wetlands have been destroyed by coastal development.[81][82] One analysis using the impact of hurricanes versus storm protection provided naturally by wetlands projected the value of this service at US$33,000/hectare/year.[83]

Water purification

Water purification can be provided by floodplains, closed-depression wetlands, mudflat, freshwater marsh, salt marsh, mangroves.

Nutrient retention: Wetlands cycle both sediments and nutrients, sometimes serving as buffers between terrestrial and aquatic ecosystems. A natural function of wetland vegetation is the up-take, storage, and (for nitrate) the removal of nutrients found in runoff water from the surrounding landscapes.[84] In many wetlands, microbial processes convert soluble nutrients to a gaseous form, such as denitrification of nitrate, which then moves the nitrate to the atmosphere mostly as harmless nitrogen gas.

Sediment and heavy metal traps: Precipitation and surface runoff induces soil erosion, transporting sediment in suspension into and through waterways. These sediments move towards larger and more sizable waterways through a natural process that moves water towards oceans. All types of sediments whether composed of clay, silt, sand or gravel and rock can be carried into wetland systems through erosion. Wetland vegetation acts as a physical barrier to slow water flow and then trap sediment for both short or long periods of time. Suspended sediment can contain heavy metals that are also retained when wetlands trap the sediment. In some cases, certain metals are taken up through wetland plant stems, roots, and leaves. For example, many floating plant species such as water hyacinth (Eichhornia crassipes), duckweed (Lemna) and water fern (Azolla) store iron and copper found in wastewater; these plants also extract pathogens. Fast-growing plants rooted in the soils of wetlands such as cattail (Typha) and reed (Phragmites) also contribute to heavy metal up-take. Animals such as the oyster can filter more than 200 litres (53 US gal) of water per day while grazing for food, removing nutrients, suspended sediments, and chemical contaminants in the process. On the other hand, some types of wetlands facilitate the mobilization and bioavailability of mercury (another heavy metal), which in its methyl mercury form increases the risk of bioaccumulation in fish important to animal food webs and harvested for human consumption.

Capacity: The ability of wetland systems to store or remove nutrients and trap sediment and associated metals is highly efficient and effective but each system has a threshold. An overabundance of nutrient input from fertilizer run-off, sewage effluent, or non-point pollution will cause eutrophication. Upstream erosion from deforestation can overwhelm wetlands making them shrink in size and cause dramatic biodiversity loss through excessive sedimentation load. Retaining high levels of metals in sediments is problematic if the sediments become resuspended or oxygen and pH levels change at a future time. The capacity of wetland vegetation to store heavy metals depends on the particular metal, oxygen and pH status of wetland sediments and overlying water, water flow rate (detention time), wetland size, season, climate, type of plant, and other factors.

The capacity of a wetland to store sediment, nutrients, and metals can be diminished if sediments are compacted such as by vehicles or heavy equipment, or are regularly tilled. Unnatural changes in water levels and water sources also can affect the water purification function. If water purification functions are impaired, excessive loads of nutrients enter waterways and cause eutrophication. This is of particular concern in temperate coastal systems.[85][86] The main sources of coastal eutrophication are industrially made nitrogen, which is used as fertilizer in agricultural practices, as well as septic waste runoff.[87] Nitrogen is the limiting nutrient for photosynthetic processes in saline systems, however in excess, it can lead to an overproduction of organic matter that then leads to hypoxic and anoxic zones within the water column.[88] Without oxygen, other organisms cannot survive, including economically important finfish and shellfish species.

Wastewater treatment

Constructed wetlands are built for wastewater treatment.

This section is an excerpt from Constructed wetland.[edit]
 
Constructed wetland in an ecological settlement in Flintenbreite near Lübeck, Germany

A constructed wetland is an artificial wetland to treat sewage, greywater, stormwater runoff or industrial wastewater.[89][90] It may also be designed for land reclamation after mining, or as a mitigation step for natural areas lost to land development. Constructed wetlands are engineered systems that use the natural functions of vegetation, soil, and organisms to provide secondary treatment to wastewater. The design of the constructed wetland has to be adjusted according to the type of wastewater to be treated. Constructed wetlands have been used in both centralized and decentralized wastewater systems. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter (measured as biochemical oxygen demand and chemical oxygen demand).[91]

Similar to natural wetlands, constructed wetlands also act as a biofilter and/or can remove a range of pollutants (such as organic matter, nutrients, pathogens, heavy metals) from the water. Constructed wetlands are designed to remove water pollutants such as suspended solids, organic matter and nutrients (nitrogen and phosphorus).[91] All types of pathogens (i.e., bacteria, viruses, protozoans and helminths) are expected to be removed to some extent in a constructed wetland. Subsurface wetlands provide greater pathogen removal than surface wetlands.[91]

There are two main types of constructed wetlands: subsurface flow and surface flow. The planted vegetation plays an important role in contaminant removal. The filter bed, consisting usually of sand and gravel, has an equally important role to play.[92] Some constructed wetlands may also serve as a habitat for native and migratory wildlife, although that is not their main purpose. Subsurface flow constructed wetlands are designed to have either horizontal flow or vertical flow of water through the gravel and sand bed. Vertical flow systems have a smaller space requirement than horizontal flow systems.

An example of how a natural wetland is used to provide some degree of sewage treatment is the East Kolkata Wetlands in Kolkata, India. The wetlands cover 125 square kilometres (48 sq mi), and are used to treat Kolkata's sewage. The nutrients contained in the wastewater sustain fish farms and agriculture.

Reservoirs of biodiversity

Wetland systems' rich biodiversity has becoming a focal point catalysed by the Ramsar Convention and World Wildlife Fund.[93] The impact of maintaining biodiversity is seen at the local level through job creation, sustainability, and community productivity. A good example is the Lower Mekong basin which runs through Cambodia, Laos, and Vietnam, supporting over 55 million people.

Biodiverse river basins: The Amazon holds more than 3,000 species of freshwater fish species within the boundaries of its basin.[94] Fishes consuming fallen fruit, e.g., the large-bodied characid, Colossoma macropomum enter the Amazonian floodplains during annual floods egesting viable seeds thus acting as an important agent of dispersal.[95] A key species which is overfished,[96] the Piramutaba catfish, Brachyplatystoma vaillantii, migrates more than 3,300 km (2,100 mi) from its nursery grounds near the mouth of the Amazon River to its spawning grounds in Andean tributaries, 400 m (1,300 ft) above sea level, distributing plants seed along the route.

Productive intertidal zones: Intertidal mudflats have a level of productivity similar to that of some wetlands even while possessing a low number of species. The abundance of invertebrates found within the mud are a food source for migratory waterfowl.[97]

Critical life-stage habitat: Mudflats, saltmarshes, mangroves, and seagrass beds have high levels of both species richness and productivity, and are home to important nursery areas for many commercial fish stocks.

Genetic diversity: Populations of many species are confined geographically to only one or a few wetland systems, often due to the long period of time that the wetlands have been physically isolated from other aquatic sources. For example, the number of endemic species in the Selenga River Delta of Lake Baikal in Russia classifies it as a hotspot for biodiversity and one of the most biodiverse wetlands in the entire world.[98]

Wetland products

 
Wetland at the Broadmoor Wildlife Sanctuary in Massachusetts, United States, in February

Wetland productivity is linked to the climate, wetland type, and nutrient availability. Low water and occasional drying of the wetland bottom during droughts (dry marsh phase) stimulates plant recruitment from a diverse seed bank and increases productivity by mobilizing nutrients. In contrast, high water during deluges (lake marsh phase) causes turnover in plant populations and increases open water, but lowers overall productivity. From open water to complete vegetation cover, annual net primary productivity may vary 20-fold.[99] The grasses of fertile floodplains such as the Nile can be highly productive, especially plants such as Arundo donax (giant reed), Cyperus papyrus (papyrus), Phragmites (reed) and Typha (cattail).[citation needed]

Wetlands naturally produce an array of vegetation and other ecological products that can be harvested for personal and commercial use.[100] Many fishes have all or part of their life-cycle occurring within a wetland system. Fresh and saltwater fish are the main source of protein for about one billion people[101] and comprise 15% of an additional 3.5 billion people's protein intake.[102] Another food staple found in wetland systems is rice, a popular grain that is consumed at the rate of one fifth of the total global calorie count. In Bangladesh, Cambodia and Vietnam, where rice paddies are predominant on the landscape, rice consumption reach 70%.[103] Some native wetland plants in the Caribbean and Australia are harvested sustainably for medicinal compounds; these include the red mangrove (Rhizophora mangle) which possesses antibacterial, wound-healing, anti-ulcer effects, and antioxidant properties.[103]

The nipa palm of Asia (sugar, vinegar, alcohol, and fodder) and honey collection from mangroves contribute to human diets and people's income. Coastal Thailand villages earn the key portion of their income from sugar production while Cuba relocates thousands of beehives each year to track the seasonal flowering of the mangrove Avicennia.[104] Other mangrove-derived products include fuelwood, salt (produced by evaporating seawater), animal fodder, traditional medicines (e.g. from mangrove bark), fibers for textiles and dyes and tannins.[105]

Over-fishing is a major problem for sustainable use of wetlands. Concerns are developing over certain aspects of farm fishing, which uses natural wetlands and waterways to harvest fish for human consumption. Aquaculture is continuing to develop rapidly throughout the Asia-Pacific region especially in China where 90% of the total number of aquaculture farms occur, contributing 80% of global value.[103] Some aquaculture has eliminated massive areas of wetland through practices such as the shrimp farming industry's destruction of mangroves. Even though the damaging impact of large-scale shrimp farming on the coastal ecosystem in many Asian countries has been widely recognized for quite some time now, it has proved difficult to mitigate since other employment avenues for people are lacking. Also burgeoning demand for shrimp globally has provided a large and ready market.[106]

Additional services and uses of wetlands

Some types of wetlands can serve as fire breaks that help slow the spread of minor wildfires. Larger wetland systems can influence local precipitation patterns. Some boreal wetland systems in catchment headwaters may help extend the period of flow and maintain water temperature in connected downstream waters.[107] Pollination services are supported by many wetlands which may provide the only suitable habitat for pollinating insects, birds, and mammals in highly developed areas.[108]

Conservation

Main article: Wetland conservation
 
Fog rising over the Mukri bog near Mukri, Estonia. The bog has an area of 2,147 hectares (5,310 acres) and has been protected since 1992.

Wetlands have historically subjected to large draining efforts for development (real estate or agriculture), and flooding to create recreational lakes or generate hydropower. Some of the world's most important agricultural areas were wetlands that have been converted to farmland.[109][110][111][112] Since the 1970s, more focus has been put on preserving wetlands for their natural functions. Since 1900 between 65-70% of the world's wetlands have been lost.[113] In order to maintain wetlands and sustain their functions, alterations and disturbances that are outside the normal range of variation should be minimized.

Balancing wetland conservation with the needs of people

Wetlands are vital ecosystems that enhance the livelihoods for the millions of people who live in and around them. The Millennium Development Goals (MDGs) called for different sectors to join forces to secure wetland environments in the context of sustainable development and improving human wellbeing. Studies have shown that it is possible to conserve wetlands while improving the livelihoods of people living among them. Case studies conducted in Malawi and Zambia looked at how dambos – wet, grassy valleys or depressions where water seeps to the surface – can be farmed sustainably. Project outcomes included a high yield of crops, development of sustainable farming techniques, and water management strategies that generate enough water for irrigation.[114]

Ramsar Convention

Main articles: Ramsar Convention and List of Ramsar wetlands of international importance

The Convention on Wetlands of International Importance, especially as Waterfowl Habitat, or Ramsar Convention, is an international treaty designed to address global concerns regarding wetland loss and degradation. The primary purposes of the treaty are to list wetlands of international importance and to promote their wise use, with the ultimate goal of preserving the world's wetlands. Methods include restricting access to some wetland areas, as well as educating the public to combat the misconception that wetlands are wastelands. The Convention works closely with five International Organisation Partners (IOPs). These are: Birdlife International, the IUCN, the International Water Management Institute, Wetlands International and the World Wide Fund for Nature. The partners provide technical expertise, help conduct or facilitate field studies and provide financial support. The IOPs also participate regularly as observers in all meetings of the Conference of the Parties and the Standing Committee and as full members of the Scientific and Technical Review Panel.

Restoration

Restoration and restoration ecologists intend to return wetlands to their natural trajectory by aiding directly with the natural processes of the ecosystem.[69] These direct methods vary with respect to the degree of physical manipulation of the natural environment and each are associated with different levels of restoration.[69] Restoration is needed after disturbance or perturbation of a wetland.[69] Disturbances include exogenous factors such as flooding or drought.[69] Other external damage may be anthropogenic disturbance caused by clear-cut harvesting of trees, oil and gas extraction, poorly defined infrastructure installation, over grazing of livestock, ill-considered recreational activities, alteration of wetlands including dredging, draining, and filling, and other negative human impacts.[69][18] Disturbance puts different levels of stress on an environment depending on the type and duration of disturbance.[69] There is no one way to restore a wetland and the level of restoration required will be based on the level of disturbance although, each method of restoration does require preparation and administration.[69]

Levels of restoration

Factors influencing selected approach may include[69] budget, time scale limitations, project goals, level of disturbance, landscape and ecological constraints, political and administrative agendas and socioeconomic priorities.

Prescribed natural or assisted regeneration

For this strategy, there is no biophysical manipulation and the ecosystem is left to recover based on the process of succession alone.[69] The focus is to eliminate and prevent further disturbance from occurring and for this type of restoration requires prior research to understand the probability that the wetland will recover naturally. This is likely to be the first method of approach since it is the least intrusive and least expensive although some biophysical non-intrusive manipulation may be required to enhance the rate of succession to an acceptable level.[69] Example methods include prescribed burns to small areas, promotion of site specific soil microbiota and plant growth using nucleation planting whereby plants radiate from an initial planting site,[115] and promotion of niche diversity or increasing the range of niches to promote use by a variety of different species.[69] These methods can make it easier for the natural species to flourish by removing environmental impediments and can speed up the process of succession.

Partial reconstruction

For this strategy, a mixture of natural regeneration and manipulated environmental control is used. This may require some engineering, and more intensive biophysical manipulations including ripping of subsoil, agrichemical applications of herbicides or insecticides, laying of mulch, mechanical seed dispersal, and tree planting on a large scale.[69] In these circumstances the wetland is impaired and without human assistance it would not recover within an acceptable period of time as determined by ecologists. Methods of restoration used will have to be determined on a site by site basis as each location will require a different approach based on levels of disturbance and the local ecosystem dynamics.[69]

Complete reconstruction

This most expensive and intrusive method of reconstruction requires engineering and ground up reconstruction. Because there is a redesign of the entire ecosystem it is important that the natural trajectory of the ecosystem be considered and that the plant species promoted will eventually return the ecosystem towards its natural trajectory.[69]

Climate change aspects

Greenhouse gas emissions

In Southeast Asia, peatswamp forests and soils are being drained, burnt, mined, and overgrazed, contributing to climate change.[116] As a result of peat drainage, the organic carbon that had built up over thousands of years and is normally under water is suddenly exposed to the air. The peat decomposes and is converted into carbon dioxide (CO2), which is then released into the atmosphere. Peat fires cause the same process to occur rapidly and in addition create enormous clouds of smoke that cross international borders, which now happens almost yearly in Southeast Asia. While peatlands constitute only 3% of the world's land area, their degradation produces 7% of all CO2 emissions.

This section is an excerpt from Greenhouse gas emissions from wetlands.[edit]

Greenhouse gas emissions from wetlands of concern consist primarily of methane and nitrous oxide emissions. Wetlands are the largest natural source of atmospheric methane in the world, and therefore remain a major area of concern with respect to climate change.[117][118][119] They contribute approximately 167 Tg of methane to the atmosphere per year.[120] Wetlands account for approximately 20 percent of atmospheric methane through emissions from soils and plants.[121] Wetlands are characterized by water-logged soils and distinctive communities of plant and animal species that have evolved and adapted to 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 can fluctuate as it is dependent on the availability of oxygen, temperature of the soil, and the composition of the soil; a warmer, more anaerobic environment with soil rich in organic matter would allow for more efficient methanogenesis.[122]

Some wetlands are a significant source of methane emissions[123][124] and some are also emitters of nitrous oxide.[125][126] 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.[127]

Climate change mitigation

Further information: Climate change mitigation § Wetland restoration

Many recent studies and reviews have favorably identified the potential for such coastal “blue carbon” ecosystems to provide a natural climate solution in two ways: by conservation, reducing the greenhouse gas emissions arising from the loss and degradation of such habitats, and by restoration, to increase carbon dioxide drawdown and its long-term storage.[128] However, CO2 removal using coastal blue carbon restoration has questionable cost-effectiveness when considered only as a climate mitigation action, either for carbon-offsetting or for inclusion in Nationally Determined Contributions.[128]

When wetlands are restored they have mitigation effects through their ability to sink carbon, converting a greenhouse gas (carbon dioxide) to solid plant material through the process of photosynthesis, and also through their ability to store and regulate water.[129][130]

Wetlands store approximately 44.6 million tonnes of carbon per year globally (estimate from 2003).[131] In salt marshes and mangrove swamps in particular, the average carbon sequestration rate is 210 g CO2 m−2 y−1 while peatlands sequester approximately 20–30 g CO2 m−2 y−1.[131][132]

Coastal wetlands, such as tropical mangroves and some temperate salt marshes, are known to be sinks for carbon that otherwise contribute to climate change in its gaseous forms (carbon dioxide and methane).[133] The ability of many tidal wetlands to store carbon and minimize methane flux from tidal sediments has led to sponsorship of blue carbon initiatives that are intended to enhance those processes.[134][135]

Climate change adaptation

Further information: Climate change adaptation

The restoration of coastal blue carbon ecosystems is highly advantageous for climate change adaptation, coastal protection, food provision and biodiversity conservation.[128]

Since the middle of the 20th century, human-caused climate change has resulted in observable changes in the global water cycle.[136]: 85  A warming climate makes extremely wet and very dry occurrences more severe, causing more severe floods and droughts. For this reason, some of the ecosystem services that wetlands provide (e.g. water storage and flood control, groundwater replenishment, shoreline stabilization and storm protection) are important for climate change adaptation measures.[137] In most parts of the world and under all emission scenarios, water cycle variability and accompanying extremes are anticipated to rise more quickly than the changes of average values.[138]: 85 

Valuation

The value of a wetland to local communities typically involves first mapping a region's wetlands, then assessing the functions and ecosystem services the wetlands provide individually and cumulatively, and finally evaluating that information to prioritize or rank individual wetlands or wetland types for conservation, management, restoration, or development.[139] Over the longer term, it requires keeping inventories[140] of known wetlands and monitoring a representative sample of the wetlands to determine changes due to both natural and human factors.

Assessment

Rapid assessment methods are used to score, rank, rate, or categorize various functions, ecosystem services, species, communities, levels of disturbance, and/or ecological health of a wetland or group of wetlands.[141] This is often done to prioritize particular wetlands for conservation (avoidance) or to determine the degree to which loss or alteration of wetland functions should be compensated, such as by restoring degraded wetlands elsewhere or providing additional protections to existing wetlands. Rapid assessment methods are also applied before and after a wetland has been restored or altered, to help monitor or predict the effects of those actions on various wetland functions and the services they provide. Assessments are typically considered to be "rapid" when they require only a single visit to the wetland lasting less than one day, which in some cases may include interpretation of aerial imagery and geographic information system (GIS) analyses of existing spatial data, but not detailed post-visit laboratory analyses of water or biological samples.

To achieve consistency among persons doing the assessment, rapid methods present indicator variables as questions or checklists on standardized data forms, and most methods standardize the scoring or rating procedure that is used to combine question responses into estimates of the levels of specified functions relative to the levels estimated in other wetlands ("calibration sites") assessed previously in a region.[142] Rapid assessment methods, partly because they often use dozens of indicators pertaining to conditions surrounding a wetland as well as within the wetland itself, aim to provide estimates of wetland functions and services that are more accurate and repeatable than simply describing a wetland's class type.[3] A need for wetland assessments to be rapid arises mostly when government agencies set deadlines for decisions affecting a wetland, or when the number of wetlands needing information on their functions or condition is large.

Inventory

Although developing a global inventory of wetlands has proven to be a large and difficult undertaking, many efforts at more local scales have been successful.[143] Current efforts are based on available data, but both classification and spatial resolution have sometimes proven to be inadequate for regional or site-specific environmental management decision-making. It is difficult to identify small, long, and narrow wetlands within the landscape. Many of today's remote sensing satellites do not have sufficient spatial and spectral resolution to monitor wetland conditions, although multispectral IKONOS[144] and QuickBird[145] data may offer improved spatial resolutions once it is 4 m or higher. Majority of the pixels are just mixtures of several plant species or vegetation types and are difficult to isolate which translates into an inability to classify the vegetation that defines the wetland.

Monitoring and mapping

A wetland needs to be monitored[146] over time to assess whether it is functioning at an ecologically sustainable level or whether it is becoming degraded.[147] Degraded wetlands will suffer a loss in water quality, loss of sensitive species, and aberrant functioning of soil geochemical processes.

Practically, many natural wetlands are difficult to monitor from the ground as they quite often are difficult to access and may require exposure to dangerous plants and animals as well as diseases borne by insects or other invertebrates. Therefore, mapping using aerial imagery[148] is one effective tool to monitor a wetland, especially a large wetland, and can also be used to monitor the status of numerous wetlands throughout a watershed or region. Many remote sensing methods can be used to map wetlands. Remote-sensing technology permits the acquisition of timely digital data on a repetitive basis. This repeat coverage allows wetlands, as well as the adjacent land-cover and land-use types, to be monitored seasonally and/or annually. Using digital data provides a standardized data-collection procedure and an opportunity for data integration within a geographic information system.

Legislation

International efforts

National efforts

United States

Each country and region tends to have its own definition of wetlands for legal purposes. In the United States, 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 generally include swamps, marshes, bogs and similar areas".[149] This definition has been used in the enforcement of the Clean Water Act. Some US states, such as Massachusetts and New York, have separate definitions that may differ from the federal government's.

In the United States Code, the term wetland is defined "as land that (A) has a predominance of hydric soils, (B) is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions and (C) under normal circumstances supports a prevalence of such vegetation." Related to these legal definitions, "normal circumstances" are expected to occur during the wet portion of the growing season under normal climatic conditions (not unusually dry or unusually wet), and in the absence of significant disturbance. It is not uncommon for a wetland to be dry for long portions of the growing season but under normal environmental conditions, the soils will be saturated to the surface or inundated creating anaerobic conditions persisting through the wet portion of the growing season.[150]

Canada

  • The Federal Policy on Wetland Conservation[151]
  • Other Individual Provincial and Territorial Based Policies[151]

Examples

See also: List of Ramsar Wetlands of International Importance, Mediterranean wetlands, List of Ramsar wetland sites in Pakistan, and List of Ramsar sites in Australia

The world's largest wetlands include the swamp forests of the Amazon River basin, the peatlands of the West Siberian Plain,[6] the Pantanal in South America,[7] and the Sundarbans in the Ganges-Brahmaputra delta.[8]

See also

References

  1. ^ a b c d e f g h i j k l m Keddy, P.A. (2010). Wetland ecology: principles and conservation (2nd ed.). New York: Cambridge University Press. ISBN 978-0521519403. [1] 2013-04-11 at the Wayback Machine
  2. ^ a b c "Official page of the Ramsar Convention". Retrieved 2011-09-25.
  3. ^ a b Dorney, J.; Savage, R.; Adamus, P.; Tiner, R., eds. (2018). Wetland and Stream Rapid Assessments: Development, Validation, and Application. London; San Diego, CA: Academic Press. ISBN 978-0-12-805091-0. OCLC 1017607532.
  4. ^ Davidson, N.C. (2014). "How much wetland has the world lost? Long-term and recent trends in global wetland area". Marine and Freshwater Research. 65 (10): 934–941. doi:10.1071/MF14173. S2CID 85617334.
  5. ^ "US EPA". 2015-09-18. Retrieved 2011-09-25.
  6. ^ a b Fraser, L.; Keddy, P.A., eds. (2005). The World's Largest Wetlands: Their Ecology and Conservation. Cambridge, UK: Cambridge University Press. ISBN 978-0521834049.
  7. ^ a b "WWF Pantanal Programme". Retrieved 2011-09-25.
  8. ^ a b Giri, C.; Pengra, B.; Zhu, Z.; Singh, A.; Tieszen, L.L. (2007). "Monitoring mangrove forest dynamics of the Sundarbans in Bangladesh and India using multi-temporal satellite data from 1973 to 2000". Estuarine, Coastal and Shelf Science. 73 (1–2): 91–100. Bibcode:2007ECSS...73...91G. doi:10.1016/j.ecss.2006.12.019.
  9. ^ "Wetlands". USDA- Natural Resource Conservation Center.
  10. ^ Davidson, N.C.; D'Cruz, R. & Finlayson, C.M. (2005). Ecosystems and Human Well-being: Wetlands and Water Synthesis: a report of the Millennium Ecosystem Assessment (PDF). Washington, DC: World Resources Institute. ISBN 978-1-56973-597-8.
  11. ^ Bange, Hermann W. (2006). "Nitrous oxide and methane in European coastal waters". Estuarine, Coastal and Shelf Science. 70 (3): 361–374. Bibcode:2006ECSS...70..361B. doi:10.1016/j.ecss.2006.05.042.
  12. ^ Thompson, A. J.; Giannopoulos, G.; Pretty, J.; Baggs, E. M.; Richardson, D. J. (2012). "Biological sources and sinks of nitrous oxide and strategies to mitigate emissions". Philosophical Transactions of the Royal Society B. 367 (1593): 1157–1168. doi:10.1098/rstb.2011.0415. PMC 3306631. PMID 22451101.
  13. ^ "Home: Oxford English Dictionary". www.oed.com. Retrieved 2022-07-08.
  14. ^ a b US EPA, OW (2015-09-18). "What is a Wetland?". US EPA. Retrieved 2022-07-08.
  15. ^ . Carpinteria Valley Water District. Archived from the original on April 25, 2012. Retrieved 2012-05-23.
  16. ^ . Mapping2.orr.noaa.gov. Archived from the original on 2012-04-25. Retrieved 2012-05-23.
  17. ^ . Alabama Power. Archived from the original on 2012-03-21. Retrieved 2012-05-23.
  18. ^ a b c d Mitsch, William J.; Gosselink, James G. (2007-08-24). Wetlands (4th ed.). New York, NY: John Wiley & Sons. ISBN 978-0-471-69967-5.
  19. ^ "The Ramsar 40th Anniversary Message for November". Ramsar. Retrieved 2011-10-10.
  20. ^ Environmental Laboratory. (1987). Corps of Engineers wetlands delineation manual. Tech. Rep. Y‐87–1.
  21. ^ Sharitz, Rebecca R.; Batzer, Darold P.; Pennings, Steven C. (2019-12-31). "Ecology of Freshwater and Estuarine Wetlands: An Introduction". Ecology of Freshwater and Estuarine Wetlands. Berkeley: University of California Press. pp. 1–22. doi:10.1525/9780520959118-003. ISBN 978-0-520-95911-8. S2CID 198427881.
  22. ^ US EPA, OW (2015-09-18). "What is a Wetland?". www.epa.gov. Retrieved 2022-08-12.
  23. ^ "Wetland Types | Department of Environmental Conservation".
  24. ^ A Directory of Important Wetlands in Australia: Third edition, Chapter 2: Wetland classification system, Criteria for inclusion and Data presentation. Australian Department of the Environment. 2001. Retrieved 30 March 2021.
  25. ^ . www.fws.gov. Archived from the original on 2014-01-21. Retrieved 2018-07-28.
  26. ^ Watson, G. E. (2006). Big Thicket Plant Ecology: An Introduction. Temple Big Thicket Series #5 (Third ed.). Denton, Texas: University of North Texas Press. ISBN 978-1574412147.
  27. ^ Texas Parks and Wildlife. Ecological Mapping systems of Texas: West Gulf Coastal Plain Seepage Swamp and Baygall 2020-07-10 at the Wayback Machine. Retrieved 7 July 2020
  28. ^ "PEATLANDS, CLIMATE CHANGE MITIGATION AND BIODIVERSITY CONSERVATION".
  29. ^ "Ramsar Convention Technical Reports".
  30. ^ Richardson, J. L.; Arndt, J. L.; Montgomery, J. A. (2001). "Hydrology of wetland and related soils". In Richardson, J. L.; Vepraskas, M. J. (eds.). Wetland Soils. Boca Raton, FL: Lewis Publishers.
  31. ^ Vitt, D. H.; Chee, W (1990). "The relationships of vegetation to surface water chemistry and peat chemistry in fens of Alberta, Canada". Plant Ecology. 89 (2): 87–106. doi:10.1007/bf00032163. S2CID 25071105.
  32. ^ Silliman, B. R.; Grosholz, E. D.; Bertness, M. D., eds. (2009). Human Impacts on Salt Marshes: A Global Perspective. Berkeley, CA: University of California Press.
  33. ^ Smith, M. J.; Schreiber, E. S. G.; Kohout, M.; Ough, K.; Lennie, R.; Turnbull, D.; Jin, C.; Clancy, T. (2007). "Wetlands as landscape units: spatial patterns in salinity and water chemistry". Wetlands, Ecology & Management. 15 (2): 95–103. doi:10.1007/s11273-006-9015-5. S2CID 20196854.
  34. ^ Ponnamperuma, F. N. (1972). The chemistry of submerged soils. Advances in Agronomy. Vol. 24. pp. 29–96. doi:10.1016/S0065-2113(08)60633-1. ISBN 9780120007240.
  35. ^ Moore, P. A. Jr.; Reddy, K. R. (1994). "Role of Eh and pH on phosphorus geochemistry in sediments of Lake Okeechobee, Florida". Journal of Environmental Quality. 23 (5): 955–964. doi:10.2134/jeq1994.00472425002300050016x. PMID 34872208.
  36. ^ Minh, L. Q.; Tuong, T. P.; van Mensvoort, M. E. F.; Bouma, J. (1998). "Soil and water table management effects on aluminum dynamics in an acid sulphate soil in Vietnam". Agriculture, Ecosystems & Environment. 68 (3): 255–262. doi:10.1016/s0167-8809(97)00158-8.
  37. ^ Schlesinger, W. A. (1997). Biogeochemistry: An Analysis of Global Change (2nd ed.). San Diego, CA: Academic Press. ISBN 9780126251555.
  38. ^ Arthington, Angela H. (2012-10-15), "Wetlands, Threats, and Water Requirements", Environmental Flows, University of California Press, pp. 243–258, doi:10.1525/california/9780520273696.003.0017, ISBN 9780520273696
  39. ^ Kelman Wieder, R.; Lang, GeraldE. (November 1984). "Influence of wetlands and coal mining on stream water chemistry". Water, Air, and Soil Pollution. 23 (4): 381. Bibcode:1984WASP...23..381K. doi:10.1007/bf00284734. ISSN 0049-6979. S2CID 96209351.
  40. ^ Jones, C Nathan; McLaughlin, Daniel L; Henson, Kevin; Haas, Carola A; Kaplan, David A (2018-01-10). "From salamanders to greenhouse gases: does upland management affect wetland functions?". Frontiers in Ecology and the Environment. 16 (1): 14–19. doi:10.1002/fee.1744. ISSN 1540-9295. S2CID 90980246.
  41. ^ Bedford, B. L. (1996). "The need to define hydrologic equivalence at the landscape scale for freshwater wetland mitigation". Ecological Applications. 6 (1): 57–68. doi:10.2307/2269552. JSTOR 2269552.
  42. ^ Nelson, M. L.; Rhoades, C. C.; Dwire, K. A. (2011). "Influences of Bedrock Geology on Water Chemistry of Slope Wetlands and Headwaters Streams in the Southern Rocky Mountains". Wetlands. 31 (2): 251–261. doi:10.1007/s13157-011-0157-8. S2CID 14521026.
  43. ^ . Archived from the original on 2011-04-10. Retrieved 2011-09-25.
  44. ^ Hutchinson, G. E. (1975). A Treatise on Limnology. Vol. 3: Limnological Botany. New York, NY: John Wiley.
  45. ^ 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.
  46. ^ Wilcox, D. A; Thompson, T. A.; Booth, R. K.; Nicholas, J. R. (2007). Lake-level variability and water availability in the Great Lakes. USGS Circular 1311.
  47. ^ Goulding, M. (1980). The Fishes and the Forest: Explorations in Amazonian Natural History. Berkeley, CA: University of California Press.
  48. ^ Colvin, Susan A. R.; Sullivan, S. Mažeika P.; Shirey, Patrick D.; Colvin, Randall W.; Winemiller, Kirk O.; Hughes, Robert M.; Fausch, Kurt D.; Infante, Dana M.; Olden, Julian D.; Bestgen, Kevin R.; Danehy, Robert J.; Eby, Lisa (2019). "Headwater Streams and Wetlands are Critical for Sustaining Fish, Fisheries, and Ecosystem Services". Fisheries. 44 (2): 73–91. doi:10.1002/fsh.10229. S2CID 92052162.
  49. ^ Sievers, Michael; Brown, Christopher J.; Tulloch, Vivitskaia J. D.; Pearson, Ryan M.; Haig, Jodie A.; Turschwell, Mischa P.; Connolly, Rod M. (2019-09-01). "The Role of Vegetated Coastal Wetlands for Marine Megafauna Conservation". Trends in Ecology & Evolution. 34 (9): 807–817. doi:10.1016/j.tree.2019.04.004. hdl:10072/391960. ISSN 0169-5347. PMID 31126633. S2CID 164219103.
  50. ^ a b c d "Ramsar Convention Ecosystem Services Benefit Factsheets". Retrieved 2011-09-25.
  51. ^ Zamberletti, Patrizia; Zaffaroni, Marta; Accatino, Francesco; Creed, Irena F.; De Michele, Carlo (2018-09-24). "Connectivity among wetlands matters for vulnerable amphibian populations in wetlandscapes". Ecological Modelling. 384: 119–127. doi:10.1016/j.ecolmodel.2018.05.008. ISSN 0304-3800. S2CID 90384249.
  52. ^ "Frogs | Bioindicators". Savethefrogs.com. 2011. Retrieved 2014-01-21.
  53. ^ Mazzotti, F.J.; Best, G.R.; Brandt, L.A.; Cherkiss, M.S.; Jeffery, B.M.; Rice, K.G. (2009). "Alligators and crocodiles as indicators for restoration of Everglades ecosystems". Ecological Indicators. 9 (6): S137−S149. doi:10.1016/j.ecolind.2008.06.008.
  54. ^ Messel, H. 1981. Surveys of tidal river systems in the Northern Territory of Australia and their crocodile populations (Vol. 1). Pergamon Press.
  55. ^ Piczak, Morgan L.; Chow-Fraser, Patricia (2019-06-01). "Assessment of critical habitat for common snapping turtles (Chelydra serpentina) in an urbanized coastal wetland". Urban Ecosystems. 22 (3): 525–537. doi:10.1007/s11252-019-00841-1. ISSN 1573-1642. S2CID 78091420.
  56. ^ Milton, W. (1999). Wetland birds: habitat resources and conservation implications. Cambridge: Cambridge University Press. ISBN 978-0511011368. OCLC 50984660.
  57. ^ Batzer, Darold; Boix, Dani, eds. (2016). Invertebrates in Freshwater Wetlands. Cham: Springer International Publishing. doi:10.1007/978-3-319-24978-0. ISBN 978-3-319-24976-6. S2CID 29672842.
  58. ^ Mas, Maria; Flaquer, Carles; Rebelo, Hugo; López‐Baucells, Adrià (2021). "Bats and wetlands: synthesising gaps in current knowledge and future opportunities for conservation". Mammal Review. 51 (3): 369–384. doi:10.1111/mam.12243. ISSN 0305-1838. S2CID 233974999.
  59. ^ Bomske, Caleb M.; Ahlers, Adam A. (2021). "How do muskrats Ondatra zibethicus affect ecosystems? A review of evidence". Mammal Review. 51 (1): 40–50. doi:10.1111/mam.12218. ISSN 0305-1838. S2CID 224916636.
  60. ^ Rosell, Frank; Bozser, Orsolya; Collen, Peter; Parker, Howard (2005). "Ecological impact of beavers Castor fiber and Castor canadensis and their ability to modify ecosystems". Mammal Review. 35 (3–4): 248–276. doi:10.1111/j.1365-2907.2005.00067.x. hdl:11250/2438080. ISSN 0305-1838.
  61. ^ Kerk, Madelon; Onorato, David P.; Hostetler, Jeffrey A.; Bolker, Benjamin M.; Oli, Madan K. (2019). "Dynamics, Persistence, and Genetic Management of the Endangered Florida Panther Population". Wildlife Monographs. 203 (1): 3–35. doi:10.1002/wmon.1041. ISSN 0084-0173. S2CID 199641325.
  62. ^ "Mammals in Wetlands". NSW Environment, Energy and Science. Department of Planning, Industry and Environment. 2020-02-20. Retrieved 2021-10-11. Mammals live in wetlands because they are adapted to the wet conditions and there is a plentiful supply of their preferred foods. For example: The swamp rat feeds on grasses, sedges, reeds, seeds and insects. The water rat feeds on a wide range of prey including large insects, crustaceans, mussels and fishes, and even frogs, lizards, small mammals and water birds. The platypus mainly feeds during the night on a wide variety of aquatic invertebrates, free-swimming organisms such as shrimps, swimming beetles, water bugs and tadpoles, and at times worms, freshwater pea mussels and snails. The fishing bat feeds on aquatic insects, small fish and flies close to the surface of rainforest streams or large lakes and reservoirs.
  63. ^ Batzer, Darold P.; Rader, Russell Ben.; Wissinger, Scott A. (1999). Invertebrates in freshwater wetlands of North America: ecology and management. New York: Wiley. ISBN 978-0471292586. OCLC 39747651.
  64. ^ Wu, Yonghong; Liu, Junzhuo; Rene, Eldon R. (2018-01-01). "Periphytic biofilms: A promising nutrient utilization regulator in wetlands". Bioresource Technology. 1st International Conference on Ecotechnologies for Controlling Non-point Source Pollution and Protecting Aquatic Ecosystem. 248 (Pt B): 44–48. doi:10.1016/j.biortech.2017.07.081. ISSN 0960-8524. PMID 28756125.
  65. ^ . Blacktown Council. Archived from the original on 2012-01-22. Retrieved 2012-05-23.
  66. ^ Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal J.; Payne, Richard J.; Roland, Thomas P.; Amesbury, Matthew J.; Lamentowicz, Mariusz; Turner, T. Edward; Gallego-Sala, Angela; Sim, Thomas; Barr, Iestyn D. (2019-10-21). "Widespread drying of European peatlands in recent centuries". Nature Geoscience. 12 (11): 922–928. Bibcode:2019NatGe..12..922S. doi:10.1038/s41561-019-0462-z. ISSN 1752-0908. S2CID 202908362. Alt URL 2020-07-27 at the Wayback Machine
  67. ^ Office of Research & Development. "Impacts on quality of inland wetlands of the United States: A survey of indicators, techniques, and applications of community-level biomonitoring data". cfpub.epa.gov. Retrieved 2018-07-27.
  68. ^ Adamus, Paul; J. Danielson, Thomas; Gonyaw, Alex (2001-03-24). Indicators for Monitoring Biological Integrity of Inland Freshwater Wetlands: A Survey of North American Technical Literature (1990-2000). 13214. doi:10.13140/rg.2.2.22371.86566.
  69. ^ a b c d e f g h i j k l m n o p q Clewell, AF; Aronson, J (2013). Ecological restoration (2nd ed.). Washington, DC: Island Press.
  70. ^ "Wetlands International works to sustain and restore wetlands for people and biodiversity". Wetlands International. Retrieved 2014-01-21.
  71. ^ Finlay, Jacques C.; Efi Foufoula-Georgiou; Dolph, Christine L.; Hansen, Amy T. (February 2018). "Contribution of wetlands to nitrate removal at the watershed scale". Nature Geoscience. 11 (2): 127–132. Bibcode:2018NatGe..11..127H. doi:10.1038/s41561-017-0056-6. ISSN 1752-0908. S2CID 46656300.
  72. ^ Alexander, David E. (1 May 1999). Encyclopedia of Environmental Science. Springer. ISBN 0-412-74050-8.
  73. ^ Keddy, P.A.; Campbell, D.; McFalls, T.; Shaffer, G.P.; Moreau, R.; Dranguet, C.; Heleniak, R. (2007). "The Wetlands of Lakes Pontchartrain and Maurepas: Past, Present and Future". Environmental Reviews. 15 (NA): 43–77. doi:10.1139/a06-008. ISSN 1181-8700.
  74. ^ Gastescu, P. (1993). The Danube Delta: geographical characteristics and ecological recovery. Earth and Environmental Science, 29, 57–67.
  75. ^ Adamus, P.R. and L.T. Stockwell. 1983. A Method for Wetland Functional Assessment. Vol. I. Critical Review and Evaluation Concepts. FHWA-IP-82-23. Federal Highway Admin., Washington, DC.
  76. ^ Millennium Ecosystem Assessment (2005). Ecosystems and human well-being: wetlands and water synthesis: a report of the Millennium Ecosystem Assessment. Washington, DC: World Resources Institute. ISBN 1-56973-597-2. OCLC 62172810.
  77. ^ Li, Luqian; Lu, XiXi; Chen, Zhongyuan (2007). "River channel change during the last 50 years in the middle Yangtze River, the Jianli reach". Geomorphology. 85 (3–4): 185–196. Bibcode:2007Geomo..85..185L. doi:10.1016/j.geomorph.2006.03.035.
  78. ^ van der Kamp, Garth; Hayashi, Masaki (2009-02-01). "Groundwater-wetland ecosystem interaction in the semiarid glaciated plains of North America". Hydrogeology Journal. 17 (1): 203–214. Bibcode:2009HydJ...17..203V. doi:10.1007/s10040-008-0367-1. ISSN 1435-0157. S2CID 129332187.
  79. ^ Costanza, Robert; Anderson, Sharolyn J.; Sutton, Paul; Mulder, Kenneth; Mulder, Obadiah; Kubiszewski, Ida; Wang, Xuantong; Liu, Xin; Pérez-Maqueo, Octavio; Luisa Martinez, M.; Jarvis, Diane; Dee, Greg (2021-09-01). "The global value of coastal wetlands for storm protection". Global Environmental Change. 70: 102328. doi:10.1016/j.gloenvcha.2021.102328. ISSN 0959-3780.
  80. ^ "United Nations Environment Programme (UNEP) – Home page". Retrieved 2011-12-11.
  81. ^ MacKinnon, J.; Verkuil, Y. I.; Murray, N. J. (2012), IUCN situation analysis on East and Southeast Asian intertidal habitats, with particular reference to the Yellow Sea (including the Bohai Sea), Occasional Paper of the IUCN Species Survival Commission No. 47, Gland, Switzerland and Cambridge, UK: IUCN, p. 70, ISBN 9782831712550, archived from the original on 2014-06-24
  82. ^ Murray, N. J.; Clemens, R. S.; Phinn, S. R.; Possingham, H. P.; Fuller, R. A. (2014). "Tracking the rapid loss of tidal wetlands in the Yellow Sea" (PDF). Frontiers in Ecology and the Environment. 12 (5): 267–272. doi:10.1890/130260.
  83. ^ . Archived from the original on 2007-09-09. Retrieved 2011-09-25.
  84. ^ "Letting Nature Do the Job". Wild.org. 2008-08-01. Archived from the original on 2013-01-13. Retrieved 2012-05-23.
  85. ^ Valiela, I.; Collins, G.; Kremer, J.; Lajtha, K.; Geist, M.; Seely, B.; Brawley, J.; Sham, C. H. (1997). "Nitrogen loading from coastal watersheds to receiving estuaries: New method and application". Ecological Applications. 7 (2): 358–380. CiteSeerX 10.1.1.461.3668. doi:10.2307/2269505. JSTOR 2269505.
  86. ^ Nixon, S. W. (1986). "Nutrients and the productivity of estuarine and coastal marine ecosystems". Journal of the Limnological Society of South Africa. 12 (1–2): 43–71. doi:10.1080/03779688.1986.9639398.
  87. ^ Galloway, J. (2003). "The Nitrogen Cascade". BioScience. 53 (4): 341–356. doi:10.1641/0006-3568(2003)053[0341:tnc]2.0.co;2. S2CID 3356400.
  88. ^ Diaz, R. J.; Rosenberg, R. (2008). "Spreading Dead Zones and Consequences for Marine Ecosystems". Science. 321 (5891): 926–929. Bibcode:2008Sci...321..926D. doi:10.1126/science.1156401. PMID 18703733. S2CID 32818786.
  89. ^ Vymazal, Jan; Zhao, Yaqian; Mander, Ülo (2021-11-01). "Recent research challenges in constructed wetlands for wastewater treatment: A review". Ecological Engineering. 169: 106318. doi:10.1016/j.ecoleng.2021.106318. ISSN 0925-8574.
  90. ^ Arden, S.; Ma, X. (2018-07-15). "Constructed wetlands for greywater recycle and reuse: A review". Science of the Total Environment. 630: 587–599. Bibcode:2018ScTEn.630..587A. doi:10.1016/j.scitotenv.2018.02.218. ISSN 0048-9697. PMC 7362998. PMID 29494968.
  91. ^ a b c Maiga, Y., von Sperling, M., Mihelcic, J. 2017. Constructed Wetlands. In: J.B. Rose and B. Jiménez-Cisneros, (eds) Global Water Pathogens Project. (C. Haas, J.R. Mihelcic and M.E. Verbyla) (eds) Part 4 Management Of Risk from Excreta and Wastewater) Michigan State University, E. Lansing, MI, UNESCO.   Material was copied from this source, which is available under a Creative Commons Attribution-ShareAlike 3.0 Unported license.
  92. ^ Hoffmann, H., Platzer, C., von Münch, E., Winker, M. (2011): Technology review of constructed wetlands – Subsurface flow constructed wetlands for greywater and domestic wastewater treatment. Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, Eschborn, Germany
  93. ^ "What is a wetland? And eight other wetland facts". World Wildlife Fund. Retrieved 2022-11-18.
  94. ^ "Amazon fish". wwf.panda.org. Retrieved 2022-11-18.
  95. ^ Anderson, Jill T.; Nuttle, Tim; Saldaña Rojas, Joe S.; Pendergast, Thomas H.; Flecker, Alexander S. (2011-11-22). "Extremely long-distance seed dispersal by an overfished Amazonian frugivore". Proceedings of the Royal Society B: Biological Sciences. 278 (1723): 3329–3335. doi:10.1098/rspb.2011.0155. PMC 3177626. PMID 21429923.
  96. ^ Prestes, Luiza; Barthem, Ronaldo; Mello-Filho, Adauto; Anderson, Elizabeth; Correa, Sandra B.; Couto, Thiago Belisario D'Araujo; Venticinque, Eduardo; Forsberg, Bruce; Cañas, Carlos; Bentes, Bianca; Goulding, Michael (2022-03-02). Aguirre, Windsor E. (ed.). "Proactively averting the collapse of Amazon fisheries based on three migratory flagship species". PLOS ONE. 17 (3): e0264490. Bibcode:2022PLoSO..1764490P. doi:10.1371/journal.pone.0264490. ISSN 1932-6203. PMC 8890642. PMID 35235610.
  97. ^ Jing, Zhu; Kai, Jing; Xiaojing, Gan; Zhijun, Ma (2007). "Food supply in intertidal area for shorebirds during stopover at Chongming Dongtan, China". Acta Ecologica Sinica. 27 (6): 2149–2159. doi:10.1016/S1872-2032(07)60045-6.
  98. ^ Lane, Charles R.; Anenkhonov, Oleg; Liu, Hongxing; Autrey, Bradley C.; Chepinoga, Victor (2015). "Classification and inventory of freshwater wetlands and aquatic habitats in the Selenga River Delta of Lake Baikal, Russia, using high-resolution satellite imagery". Wetlands Ecology and Management. 23 (2): 195–214. doi:10.1007/s11273-014-9369-z. ISSN 0923-4861. S2CID 16980247.
  99. ^ Johnson, W. C.; Millett, B. V.; Gilmanov, T.; Voldseth, R. A.; Guntenspergen, G. R. & Naugle, D. E. (2005). "Vulnerability of Northern Prairie Wetlands to Climate Change". Bio Science. 10: 863–872.
  100. ^ Maltby, E. (1986). Waterlogged wealth: why waste the world's wet places?. Earthscan. London: International Institute for Environment and Development. ISBN 978-0905347639.
  101. ^ Tidwell, James H; Allan, Geoff L (2001). "Fish as food: aquaculture's contribution: Ecological and economic impacts and contributions of fish farming and capture fisheries". EMBO Reports. 2 (11): 958–963. doi:10.1093/embo-reports/kve236. ISSN 1469-221X. PMC 1084135. PMID 11713181.
  102. ^ Béné, Christophe; Barange, Manuel; Subasinghe, Rohana; Pinstrup-Andersen, Per; Merino, Gorka; Hemre, Gro-Ingunn; Williams, Meryl (2015-04-01). "Feeding 9 billion by 2050 – Putting fish back on the menu". Food Security. 7 (2): 261–274. doi:10.1007/s12571-015-0427-z. ISSN 1876-4525. S2CID 18671617.
  103. ^ a b c "The Ramsar Information Sheet on Wetlands of International Importance". September 18, 2009. Retrieved November 19, 2011.
  104. ^ Bradbear, Nicola (2009). Bees and their role in forest livelihoods: a guide to the services provided by bees and the sustainable harvesting, processing and marketing of their products. Food and Agriculture Organization of the United Nations. Rome: Food and Agriculture Organization of the United Nations. ISBN 978-92-5-106276-0. OCLC 427853623.
  105. ^ Hogarth, Peter J. (2015). The biology of mangroves and seagrasses (Third ed.). Oxford. ISBN 978-0-19-102590-7. OCLC 907773290.
  106. ^ "Shrimp Market Size, Share & Growth Analysis Report, 2030". www.grandviewresearch.com. Retrieved 2022-11-19.
  107. ^ Leibowitz, Scott G.; Wigington, Parker J.; Schofield, Kate A.; Alexander, Laurie C.; Vanderhoof, Melanie K.; Golden, Heather E. (2018). "Connectivity of Streams and Wetlands to Downstream Waters: An Integrated Systems Framework". JAWRA Journal of the American Water Resources Association. 54 (2): 298–322. Bibcode:2018JAWRA..54..298L. doi:10.1111/1752-1688.12631. PMC 6071435. PMID 30078985.
  108. ^ McInnes, Robert J. (2016), Finlayson, C. Max; Everard, Mark; Irvine, Kenneth; McInnes, Robert J. (eds.), "Managing Wetlands for Pollination", The Wetland Book, Dordrecht: Springer Netherlands, pp. 1–4, doi:10.1007/978-94-007-6172-8_226-1, ISBN 978-94-007-6172-8, retrieved 2022-11-22
  109. ^ Van de Ven, G. P. (2004). Man-Made Lowlands: History of water management and land reclamation in the Netherlands. Utrecht: Uitgeverij Matrijs.
  110. ^ Wells, Samuel A. (1830). A History of the Drainage of the Great Level of the Fens called Bedford Level 2. London: R. Pheney.
  111. ^ Dahl, Thomas E.; Allord, Gregory J. "History of Wetlands in the Conterminous United States".
  112. ^ Lander, Brian (2014). "State Management of River Dikes in Early China: New Sources on the Environmental History of the Central Yangzi Region". T'oung Pao. 100 (4–5): 325–362. doi:10.1163/15685322-10045p02.
  113. ^ Davidson, Nick C. (2014). "How much wetland has the world lost? Long-term and recent trends in global wetland area". Marine and Freshwater Research. 65 (10): 934. doi:10.1071/MF14173. ISSN 1323-1650.
  114. ^ "Good practices and lessons learned in integrating ecosystem conservation and poverty reduction objectives in wetlands". The Ramsar Convention on Wetlands. 2008-12-01. Retrieved 10 May 2022.
  115. ^ Corbin, JD; Holl, KD (2012). "Applied nucleation as a forest restoration strategy". Forest Ecology and Management. 256: 37–46. doi:10.1016/j.foreco.2011.10.013.
  116. ^ "Wetlands International works to sustain and restore wetlands for people and biodiversity". Wetlands International. Retrieved 2014-01-21.
  117. ^ Houghton, J. T., et al. (Eds.) (2001) Projections of future climate change, Climate Change 2001: The Scientific Basis, Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, 881 pp.
  118. ^ Comyn-Platt, Edward (2018). "Carbon budgets for 1.5 and 2 °C targets lowered by natural wetland and permafrost feedbacks" (PDF). Nature. 11 (8): 568–573. Bibcode:2018NatGe..11..568C. doi:10.1038/s41561-018-0174-9. S2CID 134078252.
  119. ^ Bridgham, Scott D.; Cadillo-Quiroz, Hinsby; Keller, Jason K.; Zhuang, Qianlai (May 2013). "Methane emissions from wetlands: biogeochemical, microbial, and modeling perspectives from local to global scales". Global Change Biology. 19 (5): 1325–1346. Bibcode:2013GCBio..19.1325B. doi:10.1111/gcb.12131. PMID 23505021. S2CID 14228726.
  120. ^ "Global Methane Budget". Global Carbon Project. Retrieved 4 December 2018.
  121. ^ Bubier, Jill L.; Moore, Tim R. (December 1994). "An ecological perspective on methane emissions from northern wetlands". Trends in Ecology and Evolution. 9 (12): 460–464. doi:10.1016/0169-5347(94)90309-3. PMID 21236923.
  122. ^ Christensen, T. R., A. Ekberg, L. Strom, M. Mastepanov, N. Panikov, M. Oquist, B. H. Svenson, H. Nykanen, P. J. Martikainen, and H. Oskarsson (2003), Factors controlling large scale variations in methane emissions from wetlands, Geophys. Res. Lett., 30, 1414, doi:10.1029/2002GL016848.
  123. ^ Masso, Luana S.; Marani, Luciano; Gatti, Luciana V.; Miller, John B.; Gloor, Manuel; Melack, John; Cassol, Henrique L. G.; Tejada, Graciela; Domingues, Lucas G.; Arai, Egidio; Sanchez, Alber H.; Corrêa, Sergio M.; Anderson, Liana; Aragão, Luiz E. O. C.; Correa, Caio S. C.; Crispim, Stephane P.; Neves, Raiane A. L. (29 November 2021). "Amazon methane budget derived from multi-year airborne observations highlights regional variations in emissions". Communications Earth & Environment. 2 (1): 246. Bibcode:2021ComEE...2..246B. doi:10.1038/s43247-021-00314-4. S2CID 244711959. Retrieved 25 January 2023.
  124. ^ Tiwari, Shashank; Singh, Chhatarpal; Singh, Jay Shankar (2020). "Wetlands: A Major Natural Source Responsible for Methane Emission". In Upadhyay, Atul Kumar; Singh, Ranjan; Singh, D. P. (eds.). Restoration of Wetland Ecosystem: A Trajectory Towards a Sustainable Environment. Singapore: Springer. pp. 59–74. doi:10.1007/978-981-13-7665-8_5. ISBN 978-981-13-7665-8. S2CID 198421761.
  125. ^ Bange, Hermann W. (2006). "Nitrous oxide and methane in European coastal waters". Estuarine, Coastal and Shelf Science. 70 (3): 361–374. Bibcode:2006ECSS...70..361B. doi:10.1016/j.ecss.2006.05.042.
  126. ^ Thompson, A. J.; Giannopoulos, G.; Pretty, J.; Baggs, E. M.; Richardson, D. J. (2012). "Biological sources and sinks of nitrous oxide and strategies to mitigate emissions". Philosophical Transactions of the Royal Society B. 367 (1593): 1157–1168. doi:10.1098/rstb.2011.0415. PMC 3306631. PMID 22451101.
  127. ^ Ravishankara, A. R.; Daniel, John S.; Portmann, Robert W. (2009). "Nitrous Oxide (N2O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century". Science. 326 (5949): 123–125. Bibcode:2009Sci...326..123R. doi:10.1126/science.1176985. PMID 19713491. S2CID 2100618.
  128. ^ a b c Williamson, Phillip; Gattuso, Jean-Pierre (2022). "Carbon Removal Using Coastal Blue Carbon Ecosystems Is Uncertain and Unreliable, With Questionable Climatic Cost-Effectiveness". Frontiers in Climate. 4: 853666. doi:10.3389/fclim.2022.853666. ISSN 2624-9553.   Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License 2017-10-16 at the Wayback Machine
  129. ^ Synthesis of Adaptation Options for Coastal Areas. Climate Ready Estuaries Program, EPA 430-F-08-024. Washington, DC: US Environmental Protection Agency. 2009.
  130. ^ "Coastal Wetland Protection". Project Drawdown. 2020-02-06. Retrieved 2020-09-13.
  131. ^ a b Chmura, G. L. (2003). "Global carbon sequestration in tidal, saline wetland soils". Global Biogeochemical Cycles. 17 (4): 1111. Bibcode:2003GBioC..17.1111C. doi:10.1029/2002GB001917. S2CID 36119878.[page needed]
  132. ^ Roulet, N. T. (2000). "Peatlands, Carbon Storage, Greenhouse Gases, And The Kyoto Protocol: Prospects And Significance For Canada". Wetlands. 20 (4): 605–615. doi:10.1672/0277-5212(2000)020[0605:pcsgga]2.0.co;2. S2CID 7490212.
  133. ^ Ouyang, Xiaoguang; Lee, Shing Yip (2020-01-16). "Improved estimates on global carbon stock and carbon pools in tidal wetlands". Nature Communications. 11 (1): 317. Bibcode:2020NatCo..11..317O. doi:10.1038/s41467-019-14120-2. ISSN 2041-1723. PMC 6965625. PMID 31949151.
  134. ^ "More on blue carbon and carbon sequestration".
  135. ^ Wang, F. (2021). "Global blue carbon accumulation in tidal wetlands increases with climate change". National Science Review. 8 (9): nwaa296. doi:10.1093/nsr/nwaa296. PMC 8433083. PMID 34691731.
  136. ^ Arias, P.A., N. Bellouin, E. Coppola, R.G. Jones, G. Krinner, J. Marotzke, V. Naik, M.D. Palmer, G.-K. Plattner, J. Rogelj, M. Rojas, J. Sillmann, T. Storelvmo, P.W. Thorne, B. Trewin, K. Achuta Rao, B. Adhikary, R.P. Allan, K. Armour, G. Bala, R. Barimalala, S. Berger, J.G. Canadell, C. Cassou, A. Cherchi, W. Collins, W.D. Collins, S.L. Connors, S. Corti, F. Cruz, F.J. Dentener, C. Dereczynski, A. Di Luca, A. Diongue Niang, F.J. Doblas-Reyes, A. Dosio, H. Douville, F. Engelbrecht, V.  Eyring, E. Fischer, P. Forster, B. Fox-Kemper, J.S. Fuglestvedt, J.C. Fyfe, et al., 2021: Technical Summary 2022-07-21 at the Wayback Machine. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change 2021-08-09 at the Wayback Machine [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 33−144. doi:10.1017/9781009157896.002.
  137. ^ "Fact Sheet: Blue Carbon". American University. from the original on April 28, 2021. Retrieved 2021-04-28.
  138. ^ Arias, P.A., N. Bellouin, E. Coppola, R.G. Jones, G. Krinner, J. Marotzke, V. Naik, M.D. Palmer, G.-K. Plattner, J. Rogelj, M. Rojas, J. Sillmann, T. Storelvmo, P.W. Thorne, B. Trewin, K. Achuta Rao, B. Adhikary, R.P. Allan, K. Armour, G. Bala, R. Barimalala, S. Berger, J.G. Canadell, C. Cassou, A. Cherchi, W. Collins, W.D. Collins, S.L. Connors, S. Corti, F. Cruz, F.J. Dentener, C. Dereczynski, A. Di Luca, A. Diongue Niang, F.J. Doblas-Reyes, A. Dosio, H. Douville, F. Engelbrecht, V.  Eyring, E. Fischer, P. Forster, B. Fox-Kemper, J.S. Fuglestvedt, J.C. Fyfe, et al., 2021: Technical Summary 2022-07-21 at the Wayback Machine. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change 2021-08-09 at the Wayback Machine [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 33−144. doi:10.1017/9781009157896.002.
  139. ^ Emerton, Lucy (2016), Finlayson, C. Max; Everard, Mark; Irvine, Kenneth; McInnes, Robert J. (eds.), "Economic Valuation of Wetlands: Total Economic Value", The Wetland Book, Dordrecht: Springer Netherlands, pp. 1–6, doi:10.1007/978-94-007-6172-8_301-1, ISBN 978-94-007-6172-8, retrieved 2022-11-28
  140. ^ "A new toolkit for National Wetlands Inventories | Convention on Wetlands". www.ramsar.org. Retrieved 2022-11-28.
  141. ^ McInnes, R.J.; Everard, M. (2017). "Rapid Assessment of Wetland Ecosystem Services (RAWES): An example from Colombo, Sri Lanka". Ecosystem Services. 25: 89–105. doi:10.1016/j.ecoser.2017.03.024. S2CID 56403914.
  142. ^ Adamus, P. (2016). "Manual for the Wetland Ecosystem Services Protocol (WESP)" (PDF). Oregon State University. Retrieved July 28, 2018.
  143. ^ "Home | Ramsar Sites Information Service". rsis.ramsar.org. Retrieved 2022-11-28.
  144. ^ Wei, Anhua; Chow-Fraser, Patricia (2007). "Use of IKONOS Imagery to Map Coastal Wetlands of Georgian Bay". Fisheries. 32 (4): 167–173. doi:10.1577/1548-8446(2007)32[167:UOIITM]2.0.CO;2. ISSN 0363-2415.
  145. ^ Cook, Bruce D.; Bolstad, Paul V.; Næsset, Erik; Anderson, Ryan S.; Garrigues, Sebastian; Morisette, Jeffrey T.; Nickeson, Jaime; Davis, Kenneth J. (2009-11-16). "Using LiDAR and quickbird data to model plant production and quantify uncertainties associated with wetland detection and land cover generalizations". Remote Sensing of Environment. 113 (11): 2366–2379. Bibcode:2009RSEnv.113.2366C. doi:10.1016/j.rse.2009.06.017.
  146. ^ Stephenson, P. J.; Ntiamoa-Baidu, Yaa; Simaika, John P. (2020). "The Use of Traditional and Modern Tools for Monitoring Wetlands Biodiversity in Africa: Challenges and Opportunities". Frontiers in Environmental Science. 8. doi:10.3389/fenvs.2020.00061. ISSN 2296-665X.
  147. ^ Bhatnagar, Saheba; Gill, Laurence; Regan, Shane; Waldren, Stephen; Ghosh, Bidisha (2021-04-01). "A nested drone-satellite approach to monitoring the ecological conditions of wetlands". ISPRS Journal of Photogrammetry and Remote Sensing. 174: 151–165. Bibcode:2021JPRS..174..151B. doi:10.1016/j.isprsjprs.2021.01.012. ISSN 0924-2716. S2CID 233522024.
  148. ^ Munizaga, Juan; García, Mariano; Ureta, Fernando; Novoa, Vanessa; Rojas, Octavio; Rojas, Carolina (2022). "Mapping Coastal Wetlands Using Satellite Imagery and Machine Learning in a Highly Urbanized Landscape". Sustainability. 14 (9): 5700. doi:10.3390/su14095700. ISSN 2071-1050.
  149. ^ "EPA Regulations listed at 40 CFR 230.3(t)". US Environmental Protection Agency. March 2015. Retrieved 2014-02-18.
  150. ^ US Government Publishing Office. (2011) 16 U.S. Code Chapter 58 Subchapter I, § 3801 – Definitions 2017-02-06 at the Wayback Machine. Legal Information Institute, Cornell Law School, Ithaca.
  151. ^ a b Rubec, Clayton DA; Hanson, Alan R (2009). "Wetland mitigation and compensation: Canadian experience". Wetlands Ecol Manage. 17: 3–14. doi:10.1007/s11273-008-9078-6. S2CID 32876048.


 
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March 25, 2023
wetland, other, uses, disambiguation, simply, wetland, distinct, ecosystem, that, flooded, saturated, water, either, permanently, years, decades, seasonally, weeks, months, flooding, results, oxygen, free, anoxic, processes, prevailing, especially, soils, prim. For other uses see Wetland disambiguation Wetlands or simply a wetland is a distinct ecosystem that is flooded or saturated by water either permanently for years or decades or seasonally for weeks or months Flooding results in oxygen free anoxic processes prevailing especially in the soils 1 The primary factor that distinguishes wetlands from terrestrial land forms or water bodies is the characteristic vegetation of aquatic plants adapted to the unique anoxic hydric soils 2 Wetlands are considered among the most biologically diverse of all ecosystems serving as home to a wide range of plant and animal species Methods for assessing wetland functions wetland ecological health and general wetland condition have been developed for many regions of the world These methods have contributed to wetland conservation partly by raising public awareness of the functions some wetlands provide 3 Wetlands come in different sizes types and locations Clockwise from top left Upland vs wetland vs lacustrine zones Freshwater swamp forest in Bangladesh A freshwater cattail Typha marsh that develops with standing water and high soil fertility Peat bogs are freshwater wetlands that develop in areas with standing water and low soil fertility Wetlands occur naturally on every continent 4 The water in wetlands is either freshwater brackish or saltwater 2 The main wetland types are classified based on the dominant plants and or the source of the water For example marshes are wetlands dominated by emergent vegetation such as reeds cattails and sedges swamps are ones dominated by woody vegetation such as trees and shrubs although reed swamps in Europe are dominated by reeds not trees Examples of wetlands classified by their sources of water include tidal wetlands oceanic tides estuaries mixed tidal and river waters floodplains excess water from overflowed rivers or lakes springs seeps and fens groundwater discharge out onto the surface and bogs and vernal ponds rainfall or meltwater 1 5 Some wetlands have multiple types of plants and are fed by multiple sources of water making them difficult to classify The world s largest wetlands include the Amazon River basin the West Siberian Plain 6 the Pantanal in South America 7 and the Sundarbans in the Ganges Brahmaputra delta 8 Wetlands contribute a number of functions that benefit people These are called ecosystem services and include water purification groundwater replenishment stabilization of shorelines and storm protection water storage and flood control processing of carbon carbon fixation decomposition and sequestration other nutrients and pollutants and support of plants and animals 9 Wetlands are reservoirs of biodiversity and provide wetland products According to the UN Millennium Ecosystem Assessment wetlands are more affected by environmental degradation than any other ecosystem on Earth 10 Wetlands can be important sources and sinks of carbon depending on the specific wetland and thus will play an important role in climate change and need to be considered in attempts to mitigate climate change However some wetlands are a significant source of methane emissions and some are also emitters of nitrous oxide 11 12 Constructed wetlands are designed and built to treat municipal and industrial wastewater as well as to divert stormwater runoff Constructed wetlands may also play a role in water sensitive urban design Contents 1 Definitions and terminology 1 1 Technical definitions 1 2 Types 1 2 1 Peatlands 1 3 Wetland names 1 4 Locations 1 4 1 By temperature zone 1 4 2 By precipitation amount 2 Processes 2 1 Hydrology 2 2 Role of salinity 2 3 Soil 2 4 Water chemistry 2 5 Biota 2 5 1 Flora 2 5 2 Fauna 2 5 3 Algae 3 Disturbances and human impacts 3 1 Conversion to dry land 4 Ecosystem services 4 1 Storage reservoirs and flood protection 4 2 Groundwater replenishment 4 3 Shoreline stabilization and storm protection 4 4 Water purification 4 5 Wastewater treatment 4 6 Reservoirs of biodiversity 4 7 Wetland products 4 8 Additional services and uses of wetlands 5 Conservation 5 1 Balancing wetland conservation with the needs of people 5 2 Ramsar Convention 6 Restoration 6 1 Levels of restoration 6 1 1 Prescribed natural or assisted regeneration 6 1 2 Partial reconstruction 6 1 3 Complete reconstruction 7 Climate change aspects 7 1 Greenhouse gas emissions 7 2 Climate change mitigation 7 3 Climate change adaptation 8 Valuation 8 1 Assessment 8 2 Inventory 8 3 Monitoring and mapping 9 Legislation 9 1 International efforts 9 2 National efforts 9 2 1 United States 9 2 2 Canada 10 Examples 11 See also 12 ReferencesDefinitions and terminology Edit Marshlands are often noted within wetlands as seen here in the New Jersey Meadowlands at Lyndhurst New Jersey U S Technical definitions Edit A simplified definition of wetland is an area of land that is usually saturated with water 13 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 14 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 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 15 16 A more concise definition is a community composed of hydric soil and hydrophytes 1 Wetlands have also been described as ecotones providing a transition between dry land and water bodies 17 Wetlands exist at the interface between truly terrestrial ecosystems and aquatic systems making them inherently different from each other yet highly dependent on both 18 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 19 Article 1 1 wetlands are areas of marsh fen peatland or water whether natural or artificial permanent or temporary with water that is static or flowing fresh brackish or salt including areas of marine water the depth of which at low tide does not exceed six meters Article 2 1 Wetlands may incorporate riparian and coastal zones adjacent to the wetlands and islands or bodies of marine water deeper than six meters at low tide lying within the wetlands An ecological definition of 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 1 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 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 20 For each of these definitions and others regardless of the purpose hydrology is emphasized shallow waters water logged soils The soil characteristics and the plants and animals controlled by the wetland hydrology are often additional components of the definitions 21 Types Edit Sunrise at Viru Bog Estonia Main article Classification of wetlands Wetlands can be tidal inundated by tides or non tidal 22 The water in wetlands is either freshwater brackish or saltwater 2 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 1 Sub types include mangrove forests carrs pocosins floodplains 1 peatlands vernal pools sinks and many others 23 The following three groups are used within Australia to classify wetland by type Marine and coastal zone wetlands inland wetlands and human made wetlands 24 In the US the best known classifications are the Cowardin classification system 25 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 Edit Peatlands are 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 Wetland names Edit Variations of names for wetland systems Bayou Flooded grasslands and savannas Marsh Brackish marsh Freshwater marsh Mire Fen Bog Riparian zone Swamp Freshwater swamp forest Coniferous swamp Peat swamp forest Mangrove swamp Vernal pool 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 26 27 of the Southeastern US mallines of Argentina Mediterranean seasonal ponds of Europe and California turloughs of Ireland billabongs of Australia among many others Locations Edit By temperature zone Edit Wetlands contrast the hot arid landscape around Middle Spring Fish Springs National Wildlife Refuge Utah Wetlands are found throughout the world in different climates 14 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 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 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 28 By precipitation amount Edit 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 citation needed In some places in Southeast Asia where heavy rains occur they can receive up to 10 000 mm 390 in citation needed In some drier regions wetlands exist where as little as 180 mm 7 1 in precipitation occurs each year citation needed Temporal variation 29 Perennial systems Seasonal systems Episodic periodic or intermittent systems Ephemeral short lived systemsSurface flow may occur in some segments with subsurface flow in other segments Processes EditWetlands 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 1 When peat accumulates bogs and fens arise Hydrology Edit The most important factor producing wetlands 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 1 When peat from dead plants accumulates bogs and fens develop Wetland hydrology is associated with 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 a wetland affects hydro periods temporal fluctuations in water levels by controlling the water balance and water storage within a wetland 30 Landscape characteristics control wetland hydrology and water chemistry The O2 and CO2 concentrations of water depend on temperature atmospheric pressure and mixing with the air from winds or water flows Water chemistry within wetlands 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 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 31 Role of salinity Edit Salinity has a strong influence on wetland water chemistry particularly in coastal wetlands 1 32 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 33 Soil Edit Carbon is the major nutrient cycled within wetlands Most nutrients such as sulfur phosphorus carbon and nitrogen are found within the soil of wetlands Anaerobic and aerobic respiration in the soil influences the nutrient cycling of carbon hydrogen oxygen and nitrogen 34 and the solubility of phosphorus 35 thus contributing to the chemical variations in its water Wetlands with low pH and saline conductivity may reflect the presence of acid sulfates 36 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 37 Wetland soils are identified by redoxymorphic mottles often from iron oxide rust or low chroma intensity as determined by the Munsell Color System Water chemistry Edit Due to the low dissolved oxygen DO content and relatively low nutrient balance of wetland environments most wetlands are very susceptible to alterations in water chemistry Key factors that are assessed to determine water quality include Major anion analysis HCO3 Cl NO3 SO42 Major cation analysis Ca2 Mg2 Na K pH Conductivity conductivity increases with more dissolved ions in the water Turbidity Dissolved oxygen Temperature Total dissolved solids Gas emissions carbon dioxide and methane CO2 and CH4 These chemical factors can be used to quantify wetland disturbances and often provide information as to whether a wetland is fed by precipitation surface water or groundwater due to the different ion characteristics of the different water sources 38 Wetlands are adept at impacting the water chemistry of streams or water bodies that interact with them and can process ions that result from water pollution such as acid mine drainage or urban runoff 39 40 Biota Edit The biota of a wetland system includes its plants flora and animals fauna and microbes bacteria fungi The most important factor affecting the biota is the hydroperiod or the duration of flooding 1 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 41 and the nutrients discharged from organic matter in the soils and plants at higher elevations 42 Biota may vary within a wetland seasonally or in response to flood regimes Humid wetland in Pennsylvania before a rain Flora Edit Bud of water lotus Nelumbo nucifera an aquatic plant There are four main groups of hydrophytes that are found in wetland systems throughout the world 43 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 the surface 44 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 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 1 The upland boundary of swamps is determined partly by water levels This can be affected by dams 45 Some swamps can be dominated by a single species such as silver maple swamps around the Great Lakes 46 Others like those of the Amazon basin have large numbers of different tree species 47 Other examples include cypress Taxodium and mangrove swamps Fauna Edit Many species of frogs live in wetlands while others visit them each year to lay eggs Snapping turtles are one of the many kinds of turtles found in wetlands Many species of fish are highly dependent on wetland ecosystems 48 49 Seventy five percent of the United States commercial fish and shellfish stocks depend solely on estuaries to survive 50 Tropical fish species need mangroves for critical hatchery and nursery grounds and the coral reef system for food 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 51 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 the surrounding environment resulting in increased extinction rates in unfavorable and polluted environmental conditions 52 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 is the only place in the world where both crocodiles and alligators coexist 53 The saltwater crocodile inhabits estuaries and mangroves and can be seen along the Eastern coastline of Australia 54 Snapping turtles are one of the many kinds of turtles found in wetlands 55 Birds particularly waterfowl and wading birds use wetlands extensively 56 Mammals of wetlands 57 include numerous small and medium sized species such as voles bats 58 muskrats 59 and platypus in addition to large herbivorous and apex predator species such as the beaver 60 coypu swamp rabbit Florida panther 61 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 62 Invertebrates of wetlands include aquatic insects such as dragonflies aquatic bugs and beetles midges mosquitoes crustaceans such as crabs crayfish shrimps microcrustaceans mollusks such as clams mussels snails and worms such as polychaetes oligochaetes leeches among others Invertebrates comprise more than half of the known animal species in wetlands and are considered the primary food web link between plants and higher animals such as fish and birds 63 The low oxygen conditions in wetland water and their frequent flooding and drying daily in tidal wetlands seasonally in temporary ponds and floodplains prevent many invertebrates from inhabiting wetlands and thus the invertebrate fauna of wetlands is often less diverse than some other kinds of habitat such as streams coral reefs and forests Some wetland invertebrates thrive in habitats that lack predatory fish Many insects only inhabit wetlands as aquatic immatures nymphs larvae and the flying adults inhabit upland habitats returning to the wetlands to lay eggs For instance a common hoverfly Syritta pipiens inhabits wetlands as larvae maggots living in wet rotting organic matter these insects then visit terrestrial flowers as adult flies Algae Edit Algae are diverse plant like organisms that can vary in size color and shape Algae occur naturally in habitats such as inland lakes inter tidal zones and damp soil and provide a food source for many animals including some invertebrates fish turtles and frogs There are several groups of algae Phytoplankton are microscopic free floating algae These algae are so tiny that on average 50 of these lined up end to end would only measure one millimeter Phytoplankton are the basis of the food web in many water bodies being responsible for much of the primary production using photosynthesis to fix carbon Filamentous algae are long strands of algal cells that can form floating mats Periphyton or epiphyton are algae that grow as surface biofilms on plants wood and other substrates 64 Chara and Nitella algae are upright algae that look like a submerged plants with roots 65 Disturbances and human impacts EditSee also Human impacts on the environment Wetlands the functions and services they provide as well as their flora and fauna can be affected by several types of disturbances 66 The disturbances sometimes termed stressors or alterations can be human associated or natural direct or indirect reversible or not and isolated or cumulative Disturbances exceed the levels or patterns normally found within wetlands of a particular class in a particular region Predominant disturbances of wetlands include 67 68 Enrichment eutrophication Organic loading and reduced dissolved oxygen Contaminant toxicity Acidification Salinization Sedimentation Altered solar input turbidity shade Vegetation removal Thermal alteration Drying aridification Inundation flooding Habitat fragmentation Other human impacts Disturbances can be further categorized as follows Minor disturbance Stress that maintains ecosystem integrity 69 Moderate disturbance Ecosystem integrity is damaged but can recover in time without assistance 69 Impairment or severe disturbance Human intervention may be needed in order for ecosystem to recover 69 Just a few of the many sources of these disturbances include 70 Drainage Development Over grazing Mining Unsustainable water use Nutrient pollution anthropogenic nitrogen inputs to aquatic systems have drastically effected the dissolved nitrogen content of wetlands introducing higher nutrient availability which leads to eutrophication 71 Water pollutionThey can be manifested partly as Water scarcity Impacts to endangered species Disruption of wildlife breeding grounds Imbalance in sediment load and nutrient filtrationBiodiversity loss occurs in wetland systems through land use changes habitat destruction pollution exploitation of resources and invasive species Vulnerable threatened and endangered species include 17 of waterfowl 38 of fresh water dependent mammals 33 of freshwater fish 26 of freshwater amphibians 72 of freshwater turtles 86 of marine turtles 43 of crocodilians and 27 of coral reef building species Introduced aquatic plants in different wetland systems can have large impacts The introduction of water hyacinth a native plant of South America into Lake Victoria in East Africa as well as duckweed into non native areas of Queensland Australia have overtaken entire wetland systems overwhelming the habitats and reducing the diversity of native plants and animals This is largely due to the phenomenal growth rates of the plants and their ability to float and grow across the entire surface of the water Conversion to dry land Edit Due to their productivity wetlands are often converted into dry land with dykes and drains and used for agricultural purposes The construction of dykes and dams has negative consequences for individual wetlands and entire watersheds 1 497 Their proximity to lakes and rivers means that they are often developed for human settlement 72 Once settlements are constructed and protected by dykes the settlements then become vulnerable to land subsidence and ever increasing risk of flooding 1 497 The Mississippi River Delta around New Orleans Louisiana is a well known example 73 the Danube Delta in Europe is another 74 Ecosystem services EditFurther information Ecosystem service Depending on a wetland s geographic and topographic location 75 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 the following areas 76 Water storage flood control Groundwater replenishment Shoreline stabilization and storm protection Water purification Wastewater treatment in constructed wetlands Reservoirs of biodiversity Pollination Wetland products Cultural values Recreation and tourism Climate change mitigation and adaptationAccording to the Ramsar Convention citation needed 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 a whole Unless otherwise cited ecosystem services information is based on the following series of references 50 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 Storage reservoirs and flood protection Edit 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 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 doesn t run straight off the land into water courses This can help prevent sudden damaging floods downstream 50 Notable river systems that produce wide floodplains include the Nile River the Niger river inland delta the Zambezi River flood plain the Okavango River inland delta the Kafue River flood plain the Lake Bangweulu flood plain Africa Mississippi River USA Amazon River South America Yangtze River China Danube River Central Europe and Murray Darling River Australia Drainage of floodplains or development activities that narrow floodplain corridors such as the construction of levees reduces the ability of coupled river floodplain systems to control flood damage That is because modified and less expansive systems must still manage the same amount of precipitation causing flood peaks to be higher or deeper and floodwaters to travel faster Water management engineering developments in the past century have degraded floodplain wetlands through the construction of artificial embankments such as dykes bunds levees weirs barrages and dams All concentrate water into a main channel and waters that historically spread slowly over a large shallow area are concentrated Loss of wetland floodplains results in more severe and damaging flooding Catastrophic human impact in the Mississippi River floodplains was seen in death of several hundred individuals during a levee breach in New Orleans caused by Hurricane Katrina Human made embankments along the Yangtze River floodplains have caused the main channel of the river to become prone to more frequent and damaging flooding 77 Some of these events include the loss of riparian vegetation a 30 loss of the vegetation cover throughout the river s basin a doubling of the percentage of the land affected by soil erosion and a reduction in reservoir capacity through siltation build up in floodplain lakes 50 Groundwater replenishment Edit 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 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 78 Substrates that are porous allow water to filter down through 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 Karst cave systems are a unique example of this system and can be a connection of underground rivers influenced by rain and other forms of precipitation to the surface Shoreline stabilization and storm protection Edit Main article Integrated coastal zone management Mangroves coral reefs salt marsh can help with shoreline stabilization and storm protection Tidal and inter tidal wetland systems protect and stabilize coastal zones 79 Coral reefs provide 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 The number of people who live and work near the coast is expected to grow immensely over the next fifty years From an estimated 200 million people that currently live in low lying coastal regions the development of urban coastal centers is projected to increase the population by fivefold within 50 years 80 The United Kingdom has begun the concept of managed coastal realignment This management technique provides shoreline protection through restoration of natural wetlands rather than through applied engineering In East Asia reclamation of coastal wetlands has resulted in widespread transformation of the coastal zone and up to 65 of coastal wetlands have been destroyed by coastal development 81 82 One analysis using the impact of hurricanes versus storm protection provided naturally by wetlands projected the value of this service at US 33 000 hectare year 83 Water purification Edit Water purification can be provided by floodplains closed depression wetlands mudflat freshwater marsh salt marsh mangroves Nutrient retention Wetlands cycle both sediments and nutrients sometimes serving as buffers between terrestrial and aquatic ecosystems A natural function of wetland vegetation is the up take storage and for nitrate the removal of nutrients found in runoff water from the surrounding landscapes 84 In many wetlands microbial processes convert soluble nutrients to a gaseous form such as denitrification of nitrate which then moves the nitrate to the atmosphere mostly as harmless nitrogen gas Sediment and heavy metal traps Precipitation and surface runoff induces soil erosion transporting sediment in suspension into and through waterways These sediments move towards larger and more sizable waterways through a natural process that moves water towards oceans All types of sediments whether composed of clay silt sand or gravel and rock can be carried into wetland systems through erosion Wetland vegetation acts as a physical barrier to slow water flow and then trap sediment for both short or long periods of time Suspended sediment can contain heavy metals that are also retained when wetlands trap the sediment In some cases certain metals are taken up through wetland plant stems roots and leaves For example many floating plant species such as water hyacinth Eichhornia crassipes duckweed Lemna and water fern Azolla store iron and copper found in wastewater these plants also extract pathogens Fast growing plants rooted in the soils of wetlands such as cattail Typha and reed Phragmites also contribute to heavy metal up take Animals such as the oyster can filter more than 200 litres 53 US gal of water per day while grazing for food removing nutrients suspended sediments and chemical contaminants in the process On the other hand some types of wetlands facilitate the mobilization and bioavailability of mercury another heavy metal which in its methyl mercury form increases the risk of bioaccumulation in fish important to animal food webs and harvested for human consumption Capacity The ability of wetland systems to store or remove nutrients and trap sediment and associated metals is highly efficient and effective but each system has a threshold An overabundance of nutrient input from fertilizer run off sewage effluent or non point pollution will cause eutrophication Upstream erosion from deforestation can overwhelm wetlands making them shrink in size and cause dramatic biodiversity loss through excessive sedimentation load Retaining high levels of metals in sediments is problematic if the sediments become resuspended or oxygen and pH levels change at a future time The capacity of wetland vegetation to store heavy metals depends on the particular metal oxygen and pH status of wetland sediments and overlying water water flow rate detention time wetland size season climate type of plant and other factors The capacity of a wetland to store sediment nutrients and metals can be diminished if sediments are compacted such as by vehicles or heavy equipment or are regularly tilled Unnatural changes in water levels and water sources also can affect the water purification function If water purification functions are impaired excessive loads of nutrients enter waterways and cause eutrophication This is of particular concern in temperate coastal systems 85 86 The main sources of coastal eutrophication are industrially made nitrogen which is used as fertilizer in agricultural practices as well as septic waste runoff 87 Nitrogen is the limiting nutrient for photosynthetic processes in saline systems however in excess it can lead to an overproduction of organic matter that then leads to hypoxic and anoxic zones within the water column 88 Without oxygen other organisms cannot survive including economically important finfish and shellfish species Wastewater treatment EditConstructed wetlands are built for wastewater treatment This section is an excerpt from Constructed wetland edit Constructed wetland in an ecological settlement in Flintenbreite near Lubeck Germany A constructed wetland is an artificial wetland to treat sewage greywater stormwater runoff or industrial wastewater 89 90 It may also be designed for land reclamation after mining or as a mitigation step for natural areas lost to land development Constructed wetlands are engineered systems that use the natural functions of vegetation soil and organisms to provide secondary treatment to wastewater The design of the constructed wetland has to be adjusted according to the type of wastewater to be treated Constructed wetlands have been used in both centralized and decentralized wastewater systems Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter measured as biochemical oxygen demand and chemical oxygen demand 91 Similar to natural wetlands constructed wetlands also act as a biofilter and or can remove a range of pollutants such as organic matter nutrients pathogens heavy metals from the water Constructed wetlands are designed to remove water pollutants such as suspended solids organic matter and nutrients nitrogen and phosphorus 91 All types of pathogens i e bacteria viruses protozoans and helminths are expected to be removed to some extent in a constructed wetland Subsurface wetlands provide greater pathogen removal than surface wetlands 91 There are two main types of constructed wetlands subsurface flow and surface flow The planted vegetation plays an important role in contaminant removal The filter bed consisting usually of sand and gravel has an equally important role to play 92 Some constructed wetlands may also serve as a habitat for native and migratory wildlife although that is not their main purpose Subsurface flow constructed wetlands are designed to have either horizontal flow or vertical flow of water through the gravel and sand bed Vertical flow systems have a smaller space requirement than horizontal flow systems An example of how a natural wetland is used to provide some degree of sewage treatment is the East Kolkata Wetlands in Kolkata India The wetlands cover 125 square kilometres 48 sq mi and are used to treat Kolkata s sewage The nutrients contained in the wastewater sustain fish farms and agriculture Reservoirs of biodiversity Edit Wetland systems rich biodiversity has becoming a focal point catalysed by the Ramsar Convention and World Wildlife Fund 93 The impact of maintaining biodiversity is seen at the local level through job creation sustainability and community productivity A good example is the Lower Mekong basin which runs through Cambodia Laos and Vietnam supporting over 55 million people Biodiverse river basins The Amazon holds more than 3 000 species of freshwater fish species within the boundaries of its basin 94 Fishes consuming fallen fruit e g the large bodied characid Colossoma macropomum enter the Amazonian floodplains during annual floods egesting viable seeds thus acting as an important agent of dispersal 95 A key species which is overfished 96 the Piramutaba catfish Brachyplatystoma vaillantii migrates more than 3 300 km 2 100 mi from its nursery grounds near the mouth of the Amazon River to its spawning grounds in Andean tributaries 400 m 1 300 ft above sea level distributing plants seed along the route Productive intertidal zones Intertidal mudflats have a level of productivity similar to that of some wetlands even while possessing a low number of species The abundance of invertebrates found within the mud are a food source for migratory waterfowl 97 Critical life stage habitat Mudflats saltmarshes mangroves and seagrass beds have high levels of both species richness and productivity and are home to important nursery areas for many commercial fish stocks Genetic diversity Populations of many species are confined geographically to only one or a few wetland systems often due to the long period of time that the wetlands have been physically isolated from other aquatic sources For example the number of endemic species in the Selenga River Delta of Lake Baikal in Russia classifies it as a hotspot for biodiversity and one of the most biodiverse wetlands in the entire world 98 Wetland products Edit Wetland at the Broadmoor Wildlife Sanctuary in Massachusetts United States in February Wetland productivity is linked to the climate wetland type and nutrient availability Low water and occasional drying of the wetland bottom during droughts dry marsh phase stimulates plant recruitment from a diverse seed bank and increases productivity by mobilizing nutrients In contrast high water during deluges lake marsh phase causes turnover in plant populations and increases open water but lowers overall productivity From open water to complete vegetation cover annual net primary productivity may vary 20 fold 99 The grasses of fertile floodplains such as the Nile can be highly productive especially plants such as Arundo donax giant reed Cyperus papyrus papyrus Phragmites reed and Typha cattail citation needed Wetlands naturally produce an array of vegetation and other ecological products that can be harvested for personal and commercial use 100 Many fishes have all or part of their life cycle occurring within a wetland system Fresh and saltwater fish are the main source of protein for about one billion people 101 and comprise 15 of an additional 3 5 billion people s protein intake 102 Another food staple found in wetland systems is rice a popular grain that is consumed at the rate of one fifth of the total global calorie count In Bangladesh Cambodia and Vietnam where rice paddies are predominant on the landscape rice consumption reach 70 103 Some native wetland plants in the Caribbean and Australia are harvested sustainably for medicinal compounds these include the red mangrove Rhizophora mangle which possesses antibacterial wound healing anti ulcer effects and antioxidant properties 103 The nipa palm of Asia sugar vinegar alcohol and fodder and honey collection from mangroves contribute to human diets and people s income Coastal Thailand villages earn the key portion of their income from sugar production while Cuba relocates thousands of beehives each year to track the seasonal flowering of the mangrove Avicennia 104 Other mangrove derived products include fuelwood salt produced by evaporating seawater animal fodder traditional medicines e g from mangrove bark fibers for textiles and dyes and tannins 105 Over fishing is a major problem for sustainable use of wetlands Concerns are developing over certain aspects of farm fishing which uses natural wetlands and waterways to harvest fish for human consumption Aquaculture is continuing to develop rapidly throughout the Asia Pacific region especially in China where 90 of the total number of aquaculture farms occur contributing 80 of global value 103 Some aquaculture has eliminated massive areas of wetland through practices such as the shrimp farming industry s destruction of mangroves Even though the damaging impact of large scale shrimp farming on the coastal ecosystem in many Asian countries has been widely recognized for quite some time now it has proved difficult to mitigate since other employment avenues for people are lacking Also burgeoning demand for shrimp globally has provided a large and ready market 106 Additional services and uses of wetlands Edit Some types of wetlands can serve as fire breaks that help slow the spread of minor wildfires Larger wetland systems can influence local precipitation patterns Some boreal wetland systems in catchment headwaters may help extend the period of flow and maintain water temperature in connected downstream waters 107 Pollination services are supported by many wetlands which may provide the only suitable habitat for pollinating insects birds and mammals in highly developed areas 108 Conservation EditMain article Wetland conservation Fog rising over the Mukri bog near Mukri Estonia The bog has an area of 2 147 hectares 5 310 acres and has been protected since 1992 Wetlands have historically subjected to large draining efforts for development real estate or agriculture and flooding to create recreational lakes or generate hydropower Some of the world s most important agricultural areas were wetlands that have been converted to farmland 109 110 111 112 Since the 1970s more focus has been put on preserving wetlands for their natural functions Since 1900 between 65 70 of the world s wetlands have been lost 113 In order to maintain wetlands and sustain their functions alterations and disturbances that are outside the normal range of variation should be minimized Balancing wetland conservation with the needs of people Edit Wetlands are vital ecosystems that enhance the livelihoods for the millions of people who live in and around them The Millennium Development Goals MDGs called for different sectors to join forces to secure wetland environments in the context of sustainable development and improving human wellbeing Studies have shown that it is possible to conserve wetlands while improving the livelihoods of people living among them Case studies conducted in Malawi and Zambia looked at how dambos wet grassy valleys or depressions where water seeps to the surface can be farmed sustainably Project outcomes included a high yield of crops development of sustainable farming techniques and water management strategies that generate enough water for irrigation 114 Ramsar Convention Edit Main articles Ramsar Convention and List of Ramsar wetlands of international importance The Convention on Wetlands of International Importance especially as Waterfowl Habitat or Ramsar Convention is an international treaty designed to address global concerns regarding wetland loss and degradation The primary purposes of the treaty are to list wetlands of international importance and to promote their wise use with the ultimate goal of preserving the world s wetlands Methods include restricting access to some wetland areas as well as educating the public to combat the misconception that wetlands are wastelands The Convention works closely with five International Organisation Partners IOPs These are Birdlife International the IUCN the International Water Management Institute Wetlands International and the World Wide Fund for Nature The partners provide technical expertise help conduct or facilitate field studies and provide financial support The IOPs also participate regularly as observers in all meetings of the Conference of the Parties and the Standing Committee and as full members of the Scientific and Technical Review Panel Restoration EditRestoration and restoration ecologists intend to return wetlands to their natural trajectory by aiding directly with the natural processes of the ecosystem 69 These direct methods vary with respect to the degree of physical manipulation of the natural environment and each are associated with different levels of restoration 69 Restoration is needed after disturbance or perturbation of a wetland 69 Disturbances include exogenous factors such as flooding or drought 69 Other external damage may be anthropogenic disturbance caused by clear cut harvesting of trees oil and gas extraction poorly defined infrastructure installation over grazing of livestock ill considered recreational activities alteration of wetlands including dredging draining and filling and other negative human impacts 69 18 Disturbance puts different levels of stress on an environment depending on the type and duration of disturbance 69 There is no one way to restore a wetland and the level of restoration required will be based on the level of disturbance although each method of restoration does require preparation and administration 69 Levels of restoration Edit Factors influencing selected approach may include 69 budget time scale limitations project goals level of disturbance landscape and ecological constraints political and administrative agendas and socioeconomic priorities Prescribed natural or assisted regeneration Edit For this strategy there is no biophysical manipulation and the ecosystem is left to recover based on the process of succession alone 69 The focus is to eliminate and prevent further disturbance from occurring and for this type of restoration requires prior research to understand the probability that the wetland will recover naturally This is likely to be the first method of approach since it is the least intrusive and least expensive although some biophysical non intrusive manipulation may be required to enhance the rate of succession to an acceptable level 69 Example methods include prescribed burns to small areas promotion of site specific soil microbiota and plant growth using nucleation planting whereby plants radiate from an initial planting site 115 and promotion of niche diversity or increasing the range of niches to promote use by a variety of different species 69 These methods can make it easier for the natural species to flourish by removing environmental impediments and can speed up the process of succession Partial reconstruction Edit For this strategy a mixture of natural regeneration and manipulated environmental control is used This may require some engineering and more intensive biophysical manipulations including ripping of subsoil agrichemical applications of herbicides or insecticides laying of mulch mechanical seed dispersal and tree planting on a large scale 69 In these circumstances the wetland is impaired and without human assistance it would not recover within an acceptable period of time as determined by ecologists Methods of restoration used will have to be determined on a site by site basis as each location will require a different approach based on levels of disturbance and the local ecosystem dynamics 69 Complete reconstruction Edit This most expensive and intrusive method of reconstruction requires engineering and ground up reconstruction Because there is a redesign of the entire ecosystem it is important that the natural trajectory of the ecosystem be considered and that the plant species promoted will eventually return the ecosystem towards its natural trajectory 69 Climate change aspects EditGreenhouse gas emissions EditIn Southeast Asia peatswamp forests and soils are being drained burnt mined and overgrazed contributing to climate change 116 As a result of peat drainage the organic carbon that had built up over thousands of years and is normally under water is suddenly exposed to the air The peat decomposes and is converted into carbon dioxide CO2 which is then released into the atmosphere Peat fires cause the same process to occur rapidly and in addition create enormous clouds of smoke that cross international borders which now happens almost yearly in Southeast Asia While peatlands constitute only 3 of the world s land area their degradation produces 7 of all CO2 emissions This section is an excerpt from Greenhouse gas emissions from wetlands edit Greenhouse gas emissions from wetlands of concern consist primarily of methane and nitrous oxide emissions Wetlands are the largest natural source of atmospheric methane in the world and therefore remain a major area of concern with respect to climate change 117 118 119 They contribute approximately 167 Tg of methane to the atmosphere per year 120 Wetlands account for approximately 20 percent of atmospheric methane through emissions from soils and plants 121 Wetlands are characterized by water logged soils and distinctive communities of plant and animal species that have evolved and adapted to 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 can fluctuate as it is dependent on the availability of oxygen temperature of the soil and the composition of the soil a warmer more anaerobic environment with soil rich in organic matter would allow for more efficient methanogenesis 122 Some wetlands are a significant source of methane emissions 123 124 and some are also emitters of nitrous oxide 125 126 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 127 Climate change mitigation Edit Further information Climate change mitigation Wetland restoration Many recent studies and reviews have favorably identified the potential for such coastal blue carbon ecosystems to provide a natural climate solution in two ways by conservation reducing the greenhouse gas emissions arising from the loss and degradation of such habitats and by restoration to increase carbon dioxide drawdown and its long term storage 128 However CO2 removal using coastal blue carbon restoration has questionable cost effectiveness when considered only as a climate mitigation action either for carbon offsetting or for inclusion in Nationally Determined Contributions 128 When wetlands are restored they have mitigation effects through their ability to sink carbon converting a greenhouse gas carbon dioxide to solid plant material through the process of photosynthesis and also through their ability to store and regulate water 129 130 Wetlands store approximately 44 6 million tonnes of carbon per year globally estimate from 2003 131 In salt marshes and mangrove swamps in particular the average carbon sequestration rate is 210 g CO2 m 2 y 1 while peatlands sequester approximately 20 30 g CO2 m 2 y 1 131 132 Coastal wetlands such as tropical mangroves and some temperate salt marshes are known to be sinks for carbon that otherwise contribute to climate change in its gaseous forms carbon dioxide and methane 133 The ability of many tidal wetlands to store carbon and minimize methane flux from tidal sediments has led to sponsorship of blue carbon initiatives that are intended to enhance those processes 134 135 Climate change adaptation Edit Further information Climate change adaptation The restoration of coastal blue carbon ecosystems is highly advantageous for climate change adaptation coastal protection food provision and biodiversity conservation 128 Since the middle of the 20th century human caused climate change has resulted in observable changes in the global water cycle 136 85 A warming climate makes extremely wet and very dry occurrences more severe causing more severe floods and droughts For this reason some of the ecosystem services that wetlands provide e g water storage and flood control groundwater replenishment shoreline stabilization and storm protection are important for climate change adaptation measures 137 In most parts of the world and under all emission scenarios water cycle variability and accompanying extremes are anticipated to rise more quickly than the changes of average values 138 85 Valuation EditThe value of a wetland to local communities typically involves first mapping a region s wetlands then assessing the functions and ecosystem services the wetlands provide individually and cumulatively and finally evaluating that information to prioritize or rank individual wetlands or wetland types for conservation management restoration or development 139 Over the longer term it requires keeping inventories 140 of known wetlands and monitoring a representative sample of the wetlands to determine changes due to both natural and human factors Assessment Edit Rapid assessment methods are used to score rank rate or categorize various functions ecosystem services species communities levels of disturbance and or ecological health of a wetland or group of wetlands 141 This is often done to prioritize particular wetlands for conservation avoidance or to determine the degree to which loss or alteration of wetland functions should be compensated such as by restoring degraded wetlands elsewhere or providing additional protections to existing wetlands Rapid assessment methods are also applied before and after a wetland has been restored or altered to help monitor or predict the effects of those actions on various wetland functions and the services they provide Assessments are typically considered to be rapid when they require only a single visit to the wetland lasting less than one day which in some cases may include interpretation of aerial imagery and geographic information system GIS analyses of existing spatial data but not detailed post visit laboratory analyses of water or biological samples To achieve consistency among persons doing the assessment rapid methods present indicator variables as questions or checklists on standardized data forms and most methods standardize the scoring or rating procedure that is used to combine question responses into estimates of the levels of specified functions relative to the levels estimated in other wetlands calibration sites assessed previously in a region 142 Rapid assessment methods partly because they often use dozens of indicators pertaining to conditions surrounding a wetland as well as within the wetland itself aim to provide estimates of wetland functions and services that are more accurate and repeatable than simply describing a wetland s class type 3 A need for wetland assessments to be rapid arises mostly when government agencies set deadlines for decisions affecting a wetland or when the number of wetlands needing information on their functions or condition is large Inventory Edit Although developing a global inventory of wetlands has proven to be a large and difficult undertaking many efforts at more local scales have been successful 143 Current efforts are based on available data but both classification and spatial resolution have sometimes proven to be inadequate for regional or site specific environmental management decision making It is difficult to identify small long and narrow wetlands within the landscape Many of today s remote sensing satellites do not have sufficient spatial and spectral resolution to monitor wetland conditions although multispectral IKONOS 144 and QuickBird 145 data may offer improved spatial resolutions once it is 4 m or higher Majority of the pixels are just mixtures of several plant species or vegetation types and are difficult to isolate which translates into an inability to classify the vegetation that defines the wetland Monitoring and mapping Edit A wetland needs to be monitored 146 over time to assess whether it is functioning at an ecologically sustainable level or whether it is becoming degraded 147 Degraded wetlands will suffer a loss in water quality loss of sensitive species and aberrant functioning of soil geochemical processes Practically many natural wetlands are difficult to monitor from the ground as they quite often are difficult to access and may require exposure to dangerous plants and animals as well as diseases borne by insects or other invertebrates Therefore mapping using aerial imagery 148 is one effective tool to monitor a wetland especially a large wetland and can also be used to monitor the status of numerous wetlands throughout a watershed or region Many remote sensing methods can be used to map wetlands Remote sensing technology permits the acquisition of timely digital data on a repetitive basis This repeat coverage allows wetlands as well as the adjacent land cover and land use types to be monitored seasonally and or annually Using digital data provides a standardized data collection procedure and an opportunity for data integration within a geographic information system Legislation EditInternational efforts Edit Ramsar Convention 18 North American Waterfowl Management Plan 18 National efforts Edit United States Edit Each country and region tends to have its own definition of wetlands for legal purposes In the United States 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 generally include swamps marshes bogs and similar areas 149 This definition has been used in the enforcement of the Clean Water Act Some US states such as Massachusetts and New York have separate definitions that may differ from the federal government s In the United States Code the term wetland is defined as land that A has a predominance of hydric soils B is inundated or saturated by surface or groundwater at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions and C under normal circumstances supports a prevalence of such vegetation Related to these legal definitions normal circumstances are expected to occur during the wet portion of the growing season under normal climatic conditions not unusually dry or unusually wet and in the absence of significant disturbance It is not uncommon for a wetland to be dry for long portions of the growing season but under normal environmental conditions the soils will be saturated to the surface or inundated creating anaerobic conditions persisting through the wet portion of the growing season 150 Canada Edit The Federal Policy on Wetland Conservation 151 Other Individual Provincial and Territorial Based Policies 151 Examples EditSee also List of Ramsar Wetlands of International Importance Mediterranean wetlands List of Ramsar wetland sites in Pakistan and List of Ramsar sites in Australia The world s largest wetlands include the swamp forests of the Amazon River basin the peatlands of the West Siberian Plain 6 the Pantanal in South America 7 and the Sundarbans in the Ganges Brahmaputra delta 8 See also EditConverted wetland Groundwater dependent ecosystems Paludification Slough All pages with titles containing wetlandPortals Wetlands Environment Ecology WaterReferences Edit a b c d e f g h i j k l m Keddy P A 2010 Wetland ecology principles and conservation 2nd ed New York Cambridge University Press ISBN 978 0521519403 1 Archived 2013 04 11 at the Wayback Machine a b c Official page of the Ramsar Convention Retrieved 2011 09 25 a b Dorney J Savage R Adamus P Tiner R eds 2018 Wetland and Stream Rapid Assessments Development Validation and Application London San Diego CA Academic Press ISBN 978 0 12 805091 0 OCLC 1017607532 Davidson N C 2014 How much wetland has the world lost Long term and recent trends in global wetland area Marine and Freshwater Research 65 10 934 941 doi 10 1071 MF14173 S2CID 85617334 US EPA 2015 09 18 Retrieved 2011 09 25 a b Fraser L Keddy P A eds 2005 The World s Largest Wetlands Their Ecology and Conservation Cambridge UK Cambridge University Press ISBN 978 0521834049 a b WWF Pantanal Programme Retrieved 2011 09 25 a b Giri C Pengra B Zhu Z Singh A Tieszen L L 2007 Monitoring mangrove forest dynamics of the Sundarbans in Bangladesh and India using multi temporal satellite data from 1973 to 2000 Estuarine Coastal and Shelf Science 73 1 2 91 100 Bibcode 2007ECSS 73 91G doi 10 1016 j ecss 2006 12 019 Wetlands USDA Natural Resource Conservation Center Davidson N C D Cruz R amp Finlayson C M 2005 Ecosystems and Human Well being Wetlands and Water Synthesis a report of the Millennium Ecosystem Assessment PDF Washington DC World Resources Institute ISBN 978 1 56973 597 8 Bange Hermann W 2006 Nitrous oxide and methane in European coastal waters Estuarine Coastal and Shelf Science 70 3 361 374 Bibcode 2006ECSS 70 361B doi 10 1016 j ecss 2006 05 042 Thompson A J Giannopoulos G Pretty J Baggs E M Richardson D J 2012 Biological sources and sinks of nitrous oxide and strategies to mitigate emissions Philosophical Transactions of the Royal Society B 367 1593 1157 1168 doi 10 1098 rstb 2011 0415 PMC 3306631 PMID 22451101 Home Oxford English Dictionary www oed com Retrieved 2022 07 08 a b US EPA OW 2015 09 18 What is a Wetland US EPA Retrieved 2022 07 08 Glossary of Terms Carpinteria Valley Water District Archived from the original on April 25 2012 Retrieved 2012 05 23 Glossary Mapping2 orr noaa gov Archived from the original on 2012 04 25 Retrieved 2012 05 23 Glossary Alabama Power Archived from the original on 2012 03 21 Retrieved 2012 05 23 a b c d Mitsch William J Gosselink James G 2007 08 24 Wetlands 4th ed New York NY John Wiley amp Sons ISBN 978 0 471 69967 5 The Ramsar 40th Anniversary Message for November Ramsar Retrieved 2011 10 10 Environmental Laboratory 1987 Corps of Engineers wetlands delineation manual Tech Rep Y 87 1 Sharitz Rebecca R Batzer Darold P Pennings Steven C 2019 12 31 Ecology of Freshwater and Estuarine Wetlands An Introduction Ecology of Freshwater and Estuarine Wetlands Berkeley University of California Press pp 1 22 doi 10 1525 9780520959118 003 ISBN 978 0 520 95911 8 S2CID 198427881 US EPA OW 2015 09 18 What is a Wetland www epa gov Retrieved 2022 08 12 Wetland Types Department of Environmental Conservation A Directory of Important Wetlands in Australia Third edition Chapter 2 Wetland classification system Criteria for inclusion and Data presentation Australian Department of the Environment 2001 Retrieved 30 March 2021 NPWRC Classification of Wetlands and Deepwater Habitats of the United States www fws gov Archived from the original on 2014 01 21 Retrieved 2018 07 28 Watson G E 2006 Big Thicket Plant Ecology An Introduction Temple Big Thicket Series 5 Third ed Denton Texas University of North Texas Press ISBN 978 1574412147 Texas Parks and Wildlife Ecological Mapping systems of Texas West Gulf Coastal Plain Seepage Swamp and Baygall Archived 2020 07 10 at the Wayback Machine Retrieved 7 July 2020 PEATLANDS CLIMATE CHANGE MITIGATION AND BIODIVERSITY CONSERVATION Ramsar Convention Technical Reports Richardson J L Arndt J L Montgomery J A 2001 Hydrology of wetland and related soils In Richardson J L Vepraskas M J eds Wetland Soils Boca Raton FL Lewis Publishers Vitt D H Chee W 1990 The relationships of vegetation to surface water chemistry and peat chemistry in fens of Alberta Canada Plant Ecology 89 2 87 106 doi 10 1007 bf00032163 S2CID 25071105 Silliman B R Grosholz E D Bertness M D eds 2009 Human Impacts on Salt Marshes A Global Perspective Berkeley CA University of California Press Smith M J Schreiber E S G Kohout M Ough K Lennie R Turnbull D Jin C Clancy T 2007 Wetlands as landscape units spatial patterns in salinity and water chemistry Wetlands Ecology amp Management 15 2 95 103 doi 10 1007 s11273 006 9015 5 S2CID 20196854 Ponnamperuma F N 1972 The chemistry of submerged soils Advances in Agronomy Vol 24 pp 29 96 doi 10 1016 S0065 2113 08 60633 1 ISBN 9780120007240 Moore P A Jr Reddy K R 1994 Role of Eh and pH on phosphorus geochemistry in sediments of Lake Okeechobee Florida Journal of Environmental Quality 23 5 955 964 doi 10 2134 jeq1994 00472425002300050016x PMID 34872208 Minh L Q Tuong T P van Mensvoort M E F Bouma J 1998 Soil and water table management effects on aluminum dynamics in an acid sulphate soil in Vietnam Agriculture Ecosystems amp Environment 68 3 255 262 doi 10 1016 s0167 8809 97 00158 8 Schlesinger W A 1997 Biogeochemistry An Analysis of Global Change 2nd ed San Diego CA Academic Press ISBN 9780126251555 Arthington Angela H 2012 10 15 Wetlands Threats and Water Requirements Environmental Flows University of California Press pp 243 258 doi 10 1525 california 9780520273696 003 0017 ISBN 9780520273696 Kelman Wieder R Lang GeraldE November 1984 Influence of wetlands and coal mining on stream water chemistry Water Air and Soil Pollution 23 4 381 Bibcode 1984WASP 23 381K doi 10 1007 bf00284734 ISSN 0049 6979 S2CID 96209351 Jones C Nathan McLaughlin Daniel L Henson Kevin Haas Carola A Kaplan David A 2018 01 10 From salamanders to greenhouse gases does upland management affect wetland functions Frontiers in Ecology and the Environment 16 1 14 19 doi 10 1002 fee 1744 ISSN 1540 9295 S2CID 90980246 Bedford B L 1996 The need to define hydrologic equivalence at the landscape scale for freshwater wetland mitigation Ecological Applications 6 1 57 68 doi 10 2307 2269552 JSTOR 2269552 Nelson M L Rhoades C C Dwire K A 2011 Influences of Bedrock Geology on Water Chemistry of Slope Wetlands and Headwaters Streams in the Southern Rocky Mountains Wetlands 31 2 251 261 doi 10 1007 s13157 011 0157 8 S2CID 14521026 Blacktown Council wetlands Archived from the original on 2011 04 10 Retrieved 2011 09 25 Hutchinson G E 1975 A Treatise on Limnology Vol 3 Limnological Botany New York NY John Wiley 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 Wilcox D A Thompson T A Booth R K Nicholas J R 2007 Lake level variability and water availability in the Great Lakes USGS Circular 1311 Goulding M 1980 The Fishes and the Forest Explorations in Amazonian Natural History Berkeley CA University of California Press Colvin Susan A R Sullivan S Mazeika P Shirey Patrick D Colvin Randall W Winemiller Kirk O Hughes Robert M Fausch Kurt D Infante Dana M Olden Julian D Bestgen Kevin R Danehy Robert J Eby Lisa 2019 Headwater Streams and Wetlands are Critical for Sustaining Fish Fisheries and Ecosystem Services Fisheries 44 2 73 91 doi 10 1002 fsh 10229 S2CID 92052162 Sievers Michael Brown Christopher J Tulloch Vivitskaia J D Pearson Ryan M Haig Jodie A Turschwell Mischa P Connolly Rod M 2019 09 01 The Role of Vegetated Coastal Wetlands for Marine Megafauna Conservation Trends in Ecology amp Evolution 34 9 807 817 doi 10 1016 j tree 2019 04 004 hdl 10072 391960 ISSN 0169 5347 PMID 31126633 S2CID 164219103 a b c d Ramsar Convention Ecosystem Services Benefit Factsheets Retrieved 2011 09 25 Zamberletti Patrizia Zaffaroni Marta Accatino Francesco Creed Irena F De Michele Carlo 2018 09 24 Connectivity among wetlands matters for vulnerable amphibian populations in wetlandscapes Ecological Modelling 384 119 127 doi 10 1016 j ecolmodel 2018 05 008 ISSN 0304 3800 S2CID 90384249 Frogs Bioindicators Savethefrogs com 2011 Retrieved 2014 01 21 Mazzotti F J Best G R Brandt L A Cherkiss M S Jeffery B M Rice K G 2009 Alligators and crocodiles as indicators for restoration of Everglades ecosystems Ecological Indicators 9 6 S137 S149 doi 10 1016 j ecolind 2008 06 008 Messel H 1981 Surveys of tidal river systems in the Northern Territory of Australia and their crocodile populations Vol 1 Pergamon Press Piczak Morgan L Chow Fraser Patricia 2019 06 01 Assessment of critical habitat for common snapping turtles Chelydra serpentina in an urbanized coastal wetland Urban Ecosystems 22 3 525 537 doi 10 1007 s11252 019 00841 1 ISSN 1573 1642 S2CID 78091420 Milton W 1999 Wetland birds habitat resources and conservation implications Cambridge Cambridge University Press ISBN 978 0511011368 OCLC 50984660 Batzer Darold Boix Dani eds 2016 Invertebrates in Freshwater Wetlands Cham Springer International Publishing doi 10 1007 978 3 319 24978 0 ISBN 978 3 319 24976 6 S2CID 29672842 Mas Maria Flaquer Carles Rebelo Hugo Lopez Baucells Adria 2021 Bats and wetlands synthesising gaps in current knowledge and future opportunities for conservation Mammal Review 51 3 369 384 doi 10 1111 mam 12243 ISSN 0305 1838 S2CID 233974999 Bomske Caleb M Ahlers Adam A 2021 How do muskrats Ondatra zibethicus affect ecosystems A review of evidence Mammal Review 51 1 40 50 doi 10 1111 mam 12218 ISSN 0305 1838 S2CID 224916636 Rosell Frank Bozser Orsolya Collen Peter Parker Howard 2005 Ecological impact of beavers Castor fiber and Castor canadensis and their ability to modify ecosystems Mammal Review 35 3 4 248 276 doi 10 1111 j 1365 2907 2005 00067 x hdl 11250 2438080 ISSN 0305 1838 Kerk Madelon Onorato David P Hostetler Jeffrey A Bolker Benjamin M Oli Madan K 2019 Dynamics Persistence and Genetic Management of the Endangered Florida Panther Population Wildlife Monographs 203 1 3 35 doi 10 1002 wmon 1041 ISSN 0084 0173 S2CID 199641325 Mammals in Wetlands NSW Environment Energy and Science Department of Planning Industry and Environment 2020 02 20 Retrieved 2021 10 11 Mammals live in wetlands because they are adapted to the wet conditions and there is a plentiful supply of their preferred foods For example The swamp rat feeds on grasses sedges reeds seeds and insects The water rat feeds on a wide range of prey including large insects crustaceans mussels and fishes and even frogs lizards small mammals and water birds The platypus mainly feeds during the night on a wide variety of aquatic invertebrates free swimming organisms such as shrimps swimming beetles water bugs and tadpoles and at times worms freshwater pea mussels and snails The fishing bat feeds on aquatic insects small fish and flies close to the surface of rainforest streams or large lakes and reservoirs Batzer Darold P Rader Russell Ben Wissinger Scott A 1999 Invertebrates in freshwater wetlands of North America ecology and management New York Wiley ISBN 978 0471292586 OCLC 39747651 Wu Yonghong Liu Junzhuo Rene Eldon R 2018 01 01 Periphytic biofilms A promising nutrient utilization regulator in wetlands Bioresource Technology 1st International Conference on Ecotechnologies for Controlling Non point Source Pollution and Protecting Aquatic Ecosystem 248 Pt B 44 48 doi 10 1016 j biortech 2017 07 081 ISSN 0960 8524 PMID 28756125 Taken from Blacktown Council Wetland Inventory Blacktown Council Archived from the original on 2012 01 22 Retrieved 2012 05 23 Swindles Graeme T Morris Paul J Mullan Donal J Payne Richard J Roland Thomas P Amesbury Matthew J Lamentowicz Mariusz Turner T Edward Gallego Sala Angela Sim Thomas Barr Iestyn D 2019 10 21 Widespread drying of European peatlands in recent centuries Nature Geoscience 12 11 922 928 Bibcode 2019NatGe 12 922S doi 10 1038 s41561 019 0462 z ISSN 1752 0908 S2CID 202908362 Alt URL Archived 2020 07 27 at the Wayback Machine Office of Research amp Development Impacts on quality of inland wetlands of the United States A survey of indicators techniques and applications of community level biomonitoring data cfpub epa gov Retrieved 2018 07 27 Adamus Paul J Danielson Thomas Gonyaw Alex 2001 03 24 Indicators for Monitoring Biological Integrity of Inland Freshwater Wetlands A Survey of North American Technical Literature 1990 2000 13214 doi 10 13140 rg 2 2 22371 86566 a b c d e f g h i j k l m n o p q Clewell AF Aronson J 2013 Ecological restoration 2nd ed Washington DC Island Press Wetlands International works to sustain and restore wetlands for people and biodiversity Wetlands International Retrieved 2014 01 21 Finlay Jacques C Efi Foufoula Georgiou Dolph Christine L Hansen Amy T February 2018 Contribution of wetlands to nitrate removal at the watershed scale Nature Geoscience 11 2 127 132 Bibcode 2018NatGe 11 127H doi 10 1038 s41561 017 0056 6 ISSN 1752 0908 S2CID 46656300 Alexander David E 1 May 1999 Encyclopedia of Environmental Science Springer ISBN 0 412 74050 8 Keddy P A Campbell D McFalls T Shaffer G P Moreau R Dranguet C Heleniak R 2007 The Wetlands of Lakes Pontchartrain and Maurepas Past Present and Future Environmental Reviews 15 NA 43 77 doi 10 1139 a06 008 ISSN 1181 8700 Gastescu P 1993 The Danube Delta geographical characteristics and ecological recovery Earth and Environmental Science 29 57 67 Adamus P R and L T Stockwell 1983 A Method for Wetland Functional Assessment Vol I Critical Review and Evaluation Concepts FHWA IP 82 23 Federal Highway Admin Washington DC Millennium Ecosystem Assessment 2005 Ecosystems and human well being wetlands and water synthesis a report of the Millennium Ecosystem Assessment Washington DC World Resources Institute ISBN 1 56973 597 2 OCLC 62172810 Li Luqian Lu XiXi Chen Zhongyuan 2007 River channel change during the last 50 years in the middle Yangtze River the Jianli reach Geomorphology 85 3 4 185 196 Bibcode 2007Geomo 85 185L doi 10 1016 j geomorph 2006 03 035 van der Kamp Garth Hayashi Masaki 2009 02 01 Groundwater wetland ecosystem interaction in the semiarid glaciated plains of North America Hydrogeology Journal 17 1 203 214 Bibcode 2009HydJ 17 203V doi 10 1007 s10040 008 0367 1 ISSN 1435 0157 S2CID 129332187 Costanza Robert Anderson Sharolyn J Sutton Paul Mulder Kenneth Mulder Obadiah Kubiszewski Ida Wang Xuantong Liu Xin Perez Maqueo Octavio Luisa Martinez M Jarvis Diane Dee Greg 2021 09 01 The global value of coastal wetlands for storm protection Global Environmental Change 70 102328 doi 10 1016 j gloenvcha 2021 102328 ISSN 0959 3780 United Nations Environment Programme UNEP Home page Retrieved 2011 12 11 MacKinnon J Verkuil Y I Murray N J 2012 IUCN situation analysis on East and Southeast Asian intertidal habitats with particular reference to the Yellow Sea including the Bohai Sea Occasional Paper of the IUCN Species Survival Commission No 47 Gland Switzerland and Cambridge UK IUCN p 70 ISBN 9782831712550 archived from the original on 2014 06 24 Murray N J Clemens R S Phinn S R Possingham H P Fuller R A 2014 Tracking the rapid loss of tidal wetlands in the Yellow Sea PDF Frontiers in Ecology and the Environment 12 5 267 272 doi 10 1890 130260 FAO Archived from the original on 2007 09 09 Retrieved 2011 09 25 Letting Nature Do the Job Wild org 2008 08 01 Archived from the original on 2013 01 13 Retrieved 2012 05 23 Valiela I Collins G Kremer J Lajtha K Geist M Seely B Brawley J Sham C H 1997 Nitrogen loading from coastal watersheds to receiving estuaries New method and application Ecological Applications 7 2 358 380 CiteSeerX 10 1 1 461 3668 doi 10 2307 2269505 JSTOR 2269505 Nixon S W 1986 Nutrients and the productivity of estuarine and coastal marine ecosystems Journal of the Limnological Society of South Africa 12 1 2 43 71 doi 10 1080 03779688 1986 9639398 Galloway J 2003 The Nitrogen Cascade BioScience 53 4 341 356 doi 10 1641 0006 3568 2003 053 0341 tnc 2 0 co 2 S2CID 3356400 Diaz R J Rosenberg R 2008 Spreading Dead Zones and Consequences for Marine Ecosystems Science 321 5891 926 929 Bibcode 2008Sci 321 926D doi 10 1126 science 1156401 PMID 18703733 S2CID 32818786 Vymazal Jan Zhao Yaqian Mander Ulo 2021 11 01 Recent research challenges in constructed wetlands for wastewater treatment A review Ecological Engineering 169 106318 doi 10 1016 j ecoleng 2021 106318 ISSN 0925 8574 Arden S Ma X 2018 07 15 Constructed wetlands for greywater recycle and reuse A review Science of the Total Environment 630 587 599 Bibcode 2018ScTEn 630 587A doi 10 1016 j scitotenv 2018 02 218 ISSN 0048 9697 PMC 7362998 PMID 29494968 a b c Maiga Y von Sperling M Mihelcic J 2017 Constructed Wetlands In J B Rose and B Jimenez Cisneros eds Global Water Pathogens Project C Haas J R Mihelcic and M E Verbyla eds Part 4 Management Of Risk from Excreta and Wastewater Michigan State University E Lansing MI UNESCO Material was copied from this source which is available under a Creative Commons Attribution ShareAlike 3 0 Unported license Hoffmann H Platzer C von Munch E Winker M 2011 Technology review of constructed wetlands Subsurface flow constructed wetlands for greywater and domestic wastewater treatment Deutsche Gesellschaft fur Internationale Zusammenarbeit GIZ GmbH Eschborn Germany What is a wetland And eight other wetland facts World Wildlife Fund Retrieved 2022 11 18 Amazon fish wwf panda org Retrieved 2022 11 18 Anderson Jill T Nuttle Tim Saldana Rojas Joe S Pendergast Thomas H Flecker Alexander S 2011 11 22 Extremely long distance seed dispersal by an overfished Amazonian frugivore Proceedings of the Royal Society B Biological Sciences 278 1723 3329 3335 doi 10 1098 rspb 2011 0155 PMC 3177626 PMID 21429923 Prestes Luiza Barthem Ronaldo Mello Filho Adauto Anderson Elizabeth Correa Sandra B Couto Thiago Belisario D Araujo Venticinque Eduardo Forsberg Bruce Canas Carlos Bentes Bianca Goulding Michael 2022 03 02 Aguirre Windsor E ed Proactively averting the collapse of Amazon fisheries based on three migratory flagship species PLOS ONE 17 3 e0264490 Bibcode 2022PLoSO 1764490P doi 10 1371 journal pone 0264490 ISSN 1932 6203 PMC 8890642 PMID 35235610 Jing Zhu Kai Jing Xiaojing Gan Zhijun Ma 2007 Food supply in intertidal area for shorebirds during stopover at Chongming Dongtan China Acta Ecologica Sinica 27 6 2149 2159 doi 10 1016 S1872 2032 07 60045 6 Lane Charles R Anenkhonov Oleg Liu Hongxing Autrey Bradley C Chepinoga Victor 2015 Classification and inventory of freshwater wetlands and aquatic habitats in the Selenga River Delta of Lake Baikal Russia using high resolution satellite imagery Wetlands Ecology and Management 23 2 195 214 doi 10 1007 s11273 014 9369 z ISSN 0923 4861 S2CID 16980247 Johnson W C Millett B V Gilmanov T Voldseth R A Guntenspergen G R amp Naugle D E 2005 Vulnerability of Northern Prairie Wetlands to Climate Change Bio Science 10 863 872 Maltby E 1986 Waterlogged wealth why waste the world s wet places Earthscan London International Institute for Environment and Development ISBN 978 0905347639 Tidwell James H Allan Geoff L 2001 Fish as food aquaculture s contribution Ecological and economic impacts and contributions of fish farming and capture fisheries EMBO Reports 2 11 958 963 doi 10 1093 embo reports kve236 ISSN 1469 221X PMC 1084135 PMID 11713181 Bene Christophe Barange Manuel Subasinghe Rohana Pinstrup Andersen Per Merino Gorka Hemre Gro Ingunn Williams Meryl 2015 04 01 Feeding 9 billion by 2050 Putting fish back on the menu Food Security 7 2 261 274 doi 10 1007 s12571 015 0427 z ISSN 1876 4525 S2CID 18671617 a b c The Ramsar Information Sheet on Wetlands of International Importance September 18 2009 Retrieved November 19 2011 Bradbear Nicola 2009 Bees and their role in forest livelihoods a guide to the services provided by bees and the sustainable harvesting processing and marketing of their products Food and Agriculture Organization of the United Nations Rome Food and Agriculture Organization of the United Nations ISBN 978 92 5 106276 0 OCLC 427853623 Hogarth Peter J 2015 The biology of mangroves and seagrasses Third ed Oxford ISBN 978 0 19 102590 7 OCLC 907773290 Shrimp Market Size Share amp Growth Analysis Report 2030 www grandviewresearch com Retrieved 2022 11 19 Leibowitz Scott G Wigington Parker J Schofield Kate A Alexander Laurie C Vanderhoof Melanie K Golden Heather E 2018 Connectivity of Streams and Wetlands to Downstream Waters An Integrated Systems Framework JAWRA Journal of the American Water Resources Association 54 2 298 322 Bibcode 2018JAWRA 54 298L doi 10 1111 1752 1688 12631 PMC 6071435 PMID 30078985 McInnes Robert J 2016 Finlayson C Max Everard Mark Irvine Kenneth McInnes Robert J eds Managing Wetlands for Pollination The Wetland Book Dordrecht Springer Netherlands pp 1 4 doi 10 1007 978 94 007 6172 8 226 1 ISBN 978 94 007 6172 8 retrieved 2022 11 22 Van de Ven G P 2004 Man Made Lowlands History of water management and land reclamation in the Netherlands Utrecht Uitgeverij Matrijs Wells Samuel A 1830 A History of the Drainage of the Great Level of the Fens called Bedford Level 2 London R Pheney Dahl Thomas E Allord Gregory J History of Wetlands in the Conterminous United States Lander Brian 2014 State Management of River Dikes in Early China New Sources on the Environmental History of the Central Yangzi Region T oung Pao 100 4 5 325 362 doi 10 1163 15685322 10045p02 Davidson Nick C 2014 How much wetland has the world lost Long term and recent trends in global wetland area Marine and Freshwater Research 65 10 934 doi 10 1071 MF14173 ISSN 1323 1650 Good practices and lessons learned in integrating ecosystem conservation and poverty reduction objectives in wetlands The Ramsar Convention on Wetlands 2008 12 01 Retrieved 10 May 2022 Corbin JD Holl KD 2012 Applied nucleation as a forest restoration strategy Forest Ecology and Management 256 37 46 doi 10 1016 j foreco 2011 10 013 Wetlands International works to sustain and restore wetlands for people and biodiversity Wetlands International Retrieved 2014 01 21 Houghton J T et al Eds 2001 Projections of future climate change Climate Change 2001 The Scientific Basis Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change 881 pp Comyn Platt Edward 2018 Carbon budgets for 1 5 and 2 C targets lowered by natural wetland and permafrost feedbacks PDF Nature 11 8 568 573 Bibcode 2018NatGe 11 568C doi 10 1038 s41561 018 0174 9 S2CID 134078252 Bridgham Scott D Cadillo Quiroz Hinsby Keller Jason K Zhuang Qianlai May 2013 Methane emissions from wetlands biogeochemical microbial and modeling perspectives from local to global scales Global Change Biology 19 5 1325 1346 Bibcode 2013GCBio 19 1325B doi 10 1111 gcb 12131 PMID 23505021 S2CID 14228726 Global Methane Budget Global Carbon Project Retrieved 4 December 2018 Bubier Jill L Moore Tim R December 1994 An ecological perspective on methane emissions from northern wetlands Trends in Ecology and Evolution 9 12 460 464 doi 10 1016 0169 5347 94 90309 3 PMID 21236923 Christensen T R A Ekberg L Strom M Mastepanov N Panikov M Oquist B H Svenson H Nykanen P J Martikainen and H Oskarsson 2003 Factors controlling large scale variations in methane emissions from wetlands Geophys Res Lett 30 1414 doi 10 1029 2002GL016848 Masso Luana S Marani Luciano Gatti Luciana V Miller John B Gloor Manuel Melack John Cassol Henrique L G Tejada Graciela Domingues Lucas G Arai Egidio Sanchez Alber H Correa Sergio M Anderson Liana Aragao Luiz E O C Correa Caio S C Crispim Stephane P Neves Raiane A L 29 November 2021 Amazon methane budget derived from multi year airborne observations highlights regional variations in emissions Communications Earth amp Environment 2 1 246 Bibcode 2021ComEE 2 246B doi 10 1038 s43247 021 00314 4 S2CID 244711959 Retrieved 25 January 2023 Tiwari Shashank Singh Chhatarpal Singh Jay Shankar 2020 Wetlands A Major Natural Source Responsible for Methane Emission In Upadhyay Atul Kumar Singh Ranjan Singh D P eds Restoration of Wetland Ecosystem A Trajectory Towards a Sustainable Environment Singapore Springer pp 59 74 doi 10 1007 978 981 13 7665 8 5 ISBN 978 981 13 7665 8 S2CID 198421761 Bange Hermann W 2006 Nitrous oxide and methane in European coastal waters Estuarine Coastal and Shelf Science 70 3 361 374 Bibcode 2006ECSS 70 361B doi 10 1016 j ecss 2006 05 042 Thompson A J Giannopoulos G Pretty J Baggs E M Richardson D J 2012 Biological sources and sinks of nitrous oxide and strategies to mitigate emissions Philosophical Transactions of the Royal Society B 367 1593 1157 1168 doi 10 1098 rstb 2011 0415 PMC 3306631 PMID 22451101 Ravishankara A R Daniel John S Portmann Robert W 2009 Nitrous Oxide N2O The Dominant Ozone Depleting Substance Emitted in the 21st Century Science 326 5949 123 125 Bibcode 2009Sci 326 123R doi 10 1126 science 1176985 PMID 19713491 S2CID 2100618 a b c Williamson Phillip Gattuso Jean Pierre 2022 Carbon Removal Using Coastal Blue Carbon Ecosystems Is Uncertain and Unreliable With Questionable Climatic Cost Effectiveness Frontiers in Climate 4 853666 doi 10 3389 fclim 2022 853666 ISSN 2624 9553 Text was copied from this source which is available under a Creative Commons Attribution 4 0 International License Archived 2017 10 16 at the Wayback Machine Synthesis of Adaptation Options for Coastal Areas Climate Ready Estuaries Program EPA 430 F 08 024 Washington DC US Environmental Protection Agency 2009 Coastal Wetland Protection Project Drawdown 2020 02 06 Retrieved 2020 09 13 a b Chmura G L 2003 Global carbon sequestration in tidal saline wetland soils Global Biogeochemical Cycles 17 4 1111 Bibcode 2003GBioC 17 1111C doi 10 1029 2002GB001917 S2CID 36119878 page needed Roulet N T 2000 Peatlands Carbon Storage Greenhouse Gases And The Kyoto Protocol Prospects And Significance For Canada Wetlands 20 4 605 615 doi 10 1672 0277 5212 2000 020 0605 pcsgga 2 0 co 2 S2CID 7490212 Ouyang Xiaoguang Lee Shing Yip 2020 01 16 Improved estimates on global carbon stock and carbon pools in tidal wetlands Nature Communications 11 1 317 Bibcode 2020NatCo 11 317O doi 10 1038 s41467 019 14120 2 ISSN 2041 1723 PMC 6965625 PMID 31949151 More on blue carbon and carbon sequestration Wang F 2021 Global blue carbon accumulation in tidal wetlands increases with climate change National Science Review 8 9 nwaa296 doi 10 1093 nsr nwaa296 PMC 8433083 PMID 34691731 Arias P A N Bellouin E Coppola R G Jones G Krinner J Marotzke V Naik M D Palmer G K Plattner J Rogelj M Rojas J Sillmann T Storelvmo P W Thorne B Trewin K Achuta Rao B Adhikary R P Allan K Armour G Bala R Barimalala S Berger J G Canadell C Cassou A Cherchi W Collins W D Collins S L Connors S Corti F Cruz F J Dentener C Dereczynski A Di Luca A Diongue Niang F J Doblas Reyes A Dosio H Douville F Engelbrecht V Eyring E Fischer P Forster B Fox Kemper J S Fuglestvedt J C Fyfe et al 2021 Technical Summary Archived 2022 07 21 at the Wayback Machine In Climate Change 2021 The Physical Science Basis Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Archived 2021 08 09 at the Wayback Machine Masson Delmotte V P Zhai A Pirani S L Connors C Pean S Berger N Caud Y Chen L Goldfarb M I Gomis M Huang K Leitzell E Lonnoy J B R Matthews T K Maycock T Waterfield O Yelekci R Yu and B Zhou eds Cambridge University Press Cambridge United Kingdom and New York NY USA pp 33 144 doi 10 1017 9781009157896 002 Fact Sheet Blue Carbon American University Archived from the original on April 28 2021 Retrieved 2021 04 28 Arias P A N Bellouin E Coppola R G Jones G Krinner J Marotzke V Naik M D Palmer G K Plattner J Rogelj M Rojas J Sillmann T Storelvmo P W Thorne B Trewin K Achuta Rao B Adhikary R P Allan K Armour G Bala R Barimalala S Berger J G Canadell C Cassou A Cherchi W Collins W D Collins S L Connors S Corti F Cruz F J Dentener C Dereczynski A Di Luca A Diongue Niang F J Doblas Reyes A Dosio H Douville F Engelbrecht V Eyring E Fischer P Forster B Fox Kemper J S Fuglestvedt J C Fyfe et al 2021 Technical Summary Archived 2022 07 21 at the Wayback Machine In Climate Change 2021 The Physical Science Basis Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Archived 2021 08 09 at the Wayback Machine Masson Delmotte V P Zhai A Pirani S L Connors C Pean S Berger N Caud Y Chen L Goldfarb M I Gomis M Huang K Leitzell E Lonnoy J B R Matthews T K Maycock T Waterfield O Yelekci R Yu and B Zhou eds Cambridge University Press Cambridge United Kingdom and New York NY USA pp 33 144 doi 10 1017 9781009157896 002 Emerton Lucy 2016 Finlayson C Max Everard Mark Irvine Kenneth McInnes Robert J eds Economic Valuation of Wetlands Total Economic Value The Wetland Book Dordrecht Springer Netherlands pp 1 6 doi 10 1007 978 94 007 6172 8 301 1 ISBN 978 94 007 6172 8 retrieved 2022 11 28 A new toolkit for National Wetlands Inventories Convention on Wetlands www ramsar org Retrieved 2022 11 28 McInnes R J Everard M 2017 Rapid Assessment of Wetland Ecosystem Services RAWES An example from Colombo Sri Lanka Ecosystem Services 25 89 105 doi 10 1016 j ecoser 2017 03 024 S2CID 56403914 Adamus P 2016 Manual for the Wetland Ecosystem Services Protocol WESP PDF Oregon State University Retrieved July 28 2018 Home Ramsar Sites Information Service rsis ramsar org Retrieved 2022 11 28 Wei Anhua Chow Fraser Patricia 2007 Use of IKONOS Imagery to Map Coastal Wetlands of Georgian Bay Fisheries 32 4 167 173 doi 10 1577 1548 8446 2007 32 167 UOIITM 2 0 CO 2 ISSN 0363 2415 Cook Bruce D Bolstad Paul V Naesset Erik Anderson Ryan S Garrigues Sebastian Morisette Jeffrey T Nickeson Jaime Davis Kenneth J 2009 11 16 Using LiDAR and quickbird data to model plant production and quantify uncertainties associated with wetland detection and land cover generalizations Remote Sensing of Environment 113 11 2366 2379 Bibcode 2009RSEnv 113 2366C doi 10 1016 j rse 2009 06 017 Stephenson P J Ntiamoa Baidu Yaa Simaika John P 2020 The Use of Traditional and Modern Tools for Monitoring Wetlands Biodiversity in Africa Challenges and Opportunities Frontiers in Environmental Science 8 doi 10 3389 fenvs 2020 00061 ISSN 2296 665X Bhatnagar Saheba Gill Laurence Regan Shane Waldren Stephen Ghosh Bidisha 2021 04 01 A nested drone satellite approach to monitoring the ecological conditions of wetlands ISPRS Journal of Photogrammetry and Remote Sensing 174 151 165 Bibcode 2021JPRS 174 151B doi 10 1016 j isprsjprs 2021 01 012 ISSN 0924 2716 S2CID 233522024 Munizaga Juan Garcia Mariano Ureta Fernando Novoa Vanessa Rojas Octavio Rojas Carolina 2022 Mapping Coastal Wetlands Using Satellite Imagery and Machine Learning in a Highly Urbanized Landscape Sustainability 14 9 5700 doi 10 3390 su14095700 ISSN 2071 1050 EPA Regulations listed at 40 CFR 230 3 t US Environmental Protection Agency March 2015 Retrieved 2014 02 18 US Government Publishing Office 2011 16 U S Code Chapter 58 Subchapter I 3801 Definitions Archived 2017 02 06 at the Wayback Machine Legal Information Institute Cornell Law School Ithaca a b Rubec Clayton DA Hanson Alan R 2009 Wetland mitigation and compensation Canadian experience Wetlands Ecol Manage 17 3 14 doi 10 1007 s11273 008 9078 6 S2CID 32876048 Wikimedia Commons has media related to Wetlands Retrieved from https en wikipedia org w index php title Wetland amp oldid 1141826051, wikipedia, wiki, book, books, library,

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