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74-580: The Awarua Wetland is a peatland area of 20,000 hectares (49,000 acres) in the Southland Region of New Zealand . The site, which was initially an area of about 3,556 hectares (8,790 acres), was designated as having international significance under the Ramsar Convention in 1976, using the name Waituna Wetlands Scientific Reserve. Conservation Minister Steve Chadwick unveiled a plaque at New River Estuary on 4 May 2008. This wetland

148-580: A bog is always acidic and nutrient-poor, a fen may be slightly acidic, neutral, or alkaline, and either nutrient-poor or nutrient-rich. All mires are initially fens when the peat starts to form, and may turn into bogs once the height of the peat layer reaches above the surrounding land. A quagmire is a floating (quaking) mire, bog, or any peatland being in a stage of hydrosere or hydrarch (hydroseral) succession, resulting in pond-filling yields underfoot. Ombrotrophic types of quagmire may be called quaking bog (quivering bog). Minerotrophic types can be named with

222-604: A consequence of changes in physical and chemical compositions. The change in soil strongly affects the sensitive vegetation and forest die-off is common. The short-term effect is a decrease in biodiversity but the long-term effect, since these encroachments are hard to reverse, is a loss of habitat. Poor knowledge about peatlands' sensitive hydrology and lack of nutrients often lead to failing plantations, resulting in increasing pressure on remaining peatlands. Tropical peatland vegetation varies with climate and location. Three different characterizations are mangrove woodlands present in

296-687: A greater carbon sequestration capacity. The carbon sequestration abilities of wetlands can be improved through restoration and protection strategies, but it takes several decades for these restored ecosystems to become comparable in carbon storage to peatlands and other forms of natural wetlands. Studies highlight the critical role of peatlands in biodiversity conservation and hydrological stability. These ecosystems are unique habitats for diverse species , including specific insects and amphibians , and act as natural water reservoirs , releasing water during dry periods to sustain nearby freshwater ecosystems and agriculture . The exchange of carbon between

370-459: A peat layer but are not considered mires as the formation of new peat has ceased. There are two types of mire: bog and fen . A bog is a mire that, due to its raised location relative to the surrounding landscape, obtains all its water solely from precipitation ( ombrotrophic ). A fen is located on a slope, flat, or in a depression and gets most of its water from the surrounding mineral soil or from groundwater ( minerotrophic ). Thus, while

444-419: A quarter of global peatland area. This involves cutting drainage ditches to lower the water table with the intended purpose of enhancing the productivity of forest cover or for use as pasture or cropland. Agricultural uses for mires include the use of natural vegetation for hay crop or grazing, or the cultivation of crops on a modified surface. In addition, the commercial extraction of peat for energy production

518-649: A result of developing land use and agriculture. During the El Niño -event in 1997–1998 more than 24,400 km of peatland was lost to fires in Indonesia alone from which 10,000 km was burnt in Kalimantan and Sumatra. The output of CO 2 was estimated to 0.81–2.57 Gt, equal to 13–40% of that year's global output from fossil fuel burning. Indonesia is now considered the third-biggest contributor to global CO 2 emissions, caused primarily by these fires. With

592-561: A severe fire can release up to 4,000 t of CO 2 /ha. Burning events in tropical peatlands are becoming more frequent due to large-scale drainage and land clearance and in the past ten years, more than 2 million hectares was burnt in Southeast Asia alone. These fires last typically for 1–3 months and release large amounts of CO 2 . Indonesia is one of the countries suffering from peatland fires, especially during years with ENSO -related drought, an increasing problem since 1982 as

666-477: A substantial amount of organic matter, where humic acid dominates. Humic materials are able to store very large amounts of water, making them an essential component in the peat environment, contributing to an increased amount of carbon storage due to the resulting anaerobic condition. If the peatland is dried from long-term cultivation and agricultural use, it will lower the water table and the increased aeration will subsequently release carbon. Upon extreme drying,

740-490: A warming climate these burnings are expected to increase in intensity and number. This is a result of a dry climate together with an extensive rice farming project, called the Mega Rice Project , started in the 1990s, which converted 1 Mha of peatlands to rice paddies . Forest and land was cleared by burning and 4000 km of channels drained the area. Drought and acidification of the lands led to bad harvest and

814-433: A way that preserves the hydrological state of a mire, the anthropogenic use of mires' resources can avoid significant greenhouse gas emissions . However, continued drainage will result in increased release of carbon, contributing to global warming. As of 2016, it was estimated that drained peatlands account for around 10% of all greenhouse gas emissions from agriculture and forestry. Palm oil has increasingly become one of

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888-436: Is a key characteristic of these ecosystems. However, while ombrotrophic peat decomposes slowly, some nutrient release does occur. For example, microelements like zinc (Zn), copper (Cu), and manganese (Mn) are easily mobilized. Additionally, the presence of more nutrient-demanding species in drainage channels draining ombrotrophic bog areas suggests nutrient removal from these ecosystems. Vegetation in ombrotrophic bogs

962-515: Is a major factor as waterlogging occurs more easily on flatter ground and in basins. Peat formation typically initiates as a paludification of a mineral soil forests, terrestrialisation of lakes, or primary peat formation on bare soils on previously glaciated areas. A peatland that is actively forming peat is called a mire . All types of mires share the common characteristic of being saturated with water, at least seasonally with actively forming peat , while having their own ecosystem. Peatlands are

1036-581: Is a type of wetland within which vegetation is rooted in mineral soil. Peatlands are found around the globe, although are at their greatest extent at high latitudes in the Northern Hemisphere. Peatlands are estimated to cover around 3% of the globe's surface, although estimating the extent of their cover worldwide is difficult due to the varying accuracy and methodologies of land surveys from many countries. Mires occur wherever conditions are right for peat accumulation: largely where organic matter

1110-788: Is adapted to survive in nutrient-poor conditions, with Sphagnum mosses playing a critical role in its nutrient cycle and retention. The addition of extra nutrients and its effects on vegetation and the carbon cycle can impact an ombrotrophic bog. Increased atmospheric nitrogen (N) deposition is a major concern in northern ecosystems, which are typically nutrient-limited. Some studies suggest that N deposition may increase ecosystems' carbon dioxide (CO2) sink potential by stimulating plant productivity. High N deposition levels in Europe have led to changes in plant species composition in peatlands and tundra , with documented increases in vascular plant biomass and decreases in moss abundance, particularly

1184-540: Is combined with poor conditions for drainage. Tropical mires account for around 11% of peatlands globally (more than half of which can be found in Southeast Asia), and are most commonly found at low altitudes, although they can also be found in mountainous regions, for example in South America, Africa and Papua New Guinea . Indonesia, particularly on the islands of Sumatra, Kalimantan and Papua, has one of

1258-432: Is constantly waterlogged. Hence the distribution of mires is dependent on topography , climate, parent material, biota and time. The type of mire—bog, fen, marsh or swamp—depends also on each of these factors. The largest accumulation of mires constitutes around 64% of global peatlands and is found in the temperate, boreal and subarctic zones of the Northern Hemisphere. Mires are usually shallow in polar regions because of

1332-411: Is especially prevalent in the tropics. Peatlands release the greenhouse gas methane which has strong global warming potential . However, subtropical wetlands have shown high CO 2 binding per mol of released methane, which is a function that counteracts global warming. Tropical peatlands are suggested to contain about 100 Gt carbon, corresponding to more than 50% of the carbon present as CO 2 in

1406-496: Is estimated to be between the equivalent of 12.4 (best case) to 76.6 t CO 2 /ha (worst case). Tropical peatland converted to palm oil plantation can remain a net source of carbon to the atmosphere after 12 years. In their natural state, peatlands are resistant to fire. Drainage of peatlands for palm oil plantations creates a dry layer of flammable peat. As peat is carbon dense, fires occurring in compromised peatlands release extreme amounts of both carbon dioxide and toxic smoke into

1480-957: Is forbidden in Chile since April 2024. The Global Peatlands Initiative is an effort made by leading experts and institutions formed in 2016 by 13 founding members at the UNFCCC COP in Marrakech, Morocco. The mission of the Initiative is to protect and conserve peatlands as the world's largest terrestrial organic carbon stock and to prevent it from being emitted into the atmosphere. Ombrotrophic Ombrotrophic ("cloud-fed"), from Ancient Greek ὄμβρος ( ómvros ) meaning "rain" and τροφή ( trofí ) meaning "food"), refers to soils or vegetation which receive all of their water and nutrients from precipitation , rather than from streams or springs. Such environments are hydrologically isolated from

1554-524: Is ombrotrophic. In contrast to ombrotrophic environments, minerotrophic environments are those where the water supply comes mainly from streams or springs. This water has flowed over or through rocks often acquiring dissolved chemicals which raise the nutrient levels and reduce the acidity, which leads to different vegetation such as fen or poor fen . In most cases, ombrotrophic bogs are extremely nutrient deficient, relying solely on precipitation and atmospheric dust for nutrient supply. This deficiency

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1628-527: Is oxidised quickly and removed from the atmosphere whereas atmospheric carbon dioxide is continuously absorbed. Throughout the Holocene (the past 12,000 years), peatlands have been persistent terrestrial carbon sinks and have had a net cooling effect, sequestering 5.6 to 38 grams of carbon per square metre per year. On average, it has been estimated that today northern peatlands sequester 20 to 30 grams of carbon per square metre per year. Peatlands insulate

1702-585: Is stored in living plants, dead plants and peat, as well as converted to carbon dioxide and methane. Three main factors give wetlands the ability to sequester and store carbon: high biological productivity, high water table and low decomposition rates. Suitable meteorological and hydrological conditions are necessary to provide an abundant water source for the wetland. Fully water-saturated wetland soils allow anaerobic conditions to manifest, storing carbon but releasing methane. Wetlands make up about 5-8% of Earth's terrestrial land surface but contain about 20-30% of

1776-451: Is therefore vulnerable to changes in hydrology or vegetation cover. These peatlands are mostly located in developing regions with impoverished and rapidly growing populations. These lands have become targets for commercial logging , paper pulp production and conversion to plantations through clear-cutting , drainage and burning. Drainage of tropical peatlands alters the hydrology and increases their susceptibility to fire and soil erosion, as

1850-496: Is unclear whether this pattern would continue under higher N deposition levels. With a warmer and drier climate , without the effect of N deposition, bog communities in Canada are likely to shift and could become weaker C sinks or even C sources. Ombrotrophic bogs have also been assessed for their uses as archives of atmospheric mercury deposition. This involves studying the solid state distributions of mercury and other metals in

1924-663: Is unique in New Zealand as it includes privately owned ground (Gamble, Nicol, and Rance families). On the northeast corner of the Toetoes Wetlands is an area of native bush of approximately 25 hectares (62 acres), which along with other areas of bush close by was covenanted to the QEII Trust by the Nicol Family. While not a true wetland it is an area of natural vegetation with an unmodified stream flowing from

1998-584: Is widely practiced in Northern European countries, such as Russia, Sweden, Finland, Ireland and the Baltic states . Tropical peatlands comprise 0.25% of Earth's terrestrial land surface but store 3% of all soil and forest carbon stocks. The use of this land by humans, including draining and harvesting of tropical peat forests, results in the emission of large amounts of carbon dioxide into the atmosphere. In addition, fires occurring on peatland dried by

2072-565: The permafrost in subarctic regions, thus delaying thawing during summer, as well as inducing the formation of permafrost. As the global climate continues to warm, wetlands could become major carbon sources as higher temperatures cause higher carbon dioxide emissions. Compared with untilled cropland, wetlands can sequester around two times the carbon. Carbon sequestration can occur in constructed wetlands as well as natural ones. Estimates of greenhouse gas fluxes from wetlands indicate that natural wetlands have lower fluxes, but man-made wetlands have

2146-481: The CO 2 molecules compared with methane and nitrous oxide, peatlands have had a net cooling effect on the atmosphere. The water table position of a peatland is the main control of its carbon release to the atmosphere. When the water table rises after a rainstorm, the peat and its microbes are submerged under water inhibiting access to oxygen, reducing CO 2 release via respiration. Carbon dioxide release increases when

2220-476: The air. These fires add to greenhouse gas emissions while also causing thousands of deaths every year. Decreased biodiversity due to deforestation and drainage makes these ecosystem more vulnerable and less resilient to change. Homogenous ecosystems are at an increased risk to extreme climate conditions and are less likely to recover from fires. Some peatlands are being dried out by climate change . Drainage of peatlands due to climatic factors may also increase

2294-441: The amount of carbon found in the atmosphere . Peatlands interact with the atmosphere primarily through the exchange of carbon dioxide , methane and nitrous oxide , and can be damaged by excess nitrogen from agriculture or rainwater. The sequestration of carbon dioxide takes place at the surface via the process of photosynthesis , while losses of carbon dioxide occur through living plants via autotrophic respiration and from

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2368-524: The anoxic state of water-logged peat, which slows down decomposition. Peat-forming vegetation is typically also recalcitrant (poorly decomposing) due to high lignin and low nutrient content. Topographically , accumulating peat elevates the ground surface above the original topography. Mires can reach considerable heights above the underlying mineral soil or bedrock : peat depths of above 10 m have been commonly recorded in temperate regions (many temperate and most boreal mires were removed by ice sheets in

2442-400: The atmosphere, further exacerbating climate change. For botanists and ecologists, the term peatland is a general term for any terrain dominated by peat to a depth of at least 30 cm (12 in), even if it has been completely drained (i.e., a peatland can be dry). A peatland that is still capable of forming new peat is called a mire , while drained and converted peatlands might still have

2516-463: The atmosphere. Accumulation rates of carbon during the last millennium were close to 40 g C/m /yr. Northern peatlands are associated with boreal and subarctic climates. Northern peatlands were mostly built up during the Holocene after the retreat of Pleistocene glaciers, but in contrast tropical peatlands are much older. Total northern peat carbon stocks are estimated to be 1055 Gt of carbon. Of all northern circumpolar countries, Russia has

2590-546: The bog to understand postdepositional transport processes and the immobility of deposited trace metals. It was found that mercury (Hg) and lead (Pb) are immobile in ombrotrophic peat, indicating that their distribution can be used to determine temporal changes in deposition and suggesting that ombrotrophic bogs can serve as reliable records of historic atmospheric mercury deposition. Historic atmospheric mercury deposition in Arlberg Bog, Minnesota , increased gradually after

2664-589: The coasts of the north-east and south Pacific, and the north-west and north-east Atlantic. In the sub-tropics, mires are rare and restricted to the wettest areas. Mires can be extensive in the tropics, typically underlying tropical rainforest (for example, in Kalimantan , the Congo Basin and Amazon basin ). Tropical peat formation is known to occur in coastal mangroves as well as in areas of high altitude. Tropical mires largely form where high precipitation

2738-406: The conversion of organics to carbon dioxide to be released in the atmosphere. Records of past human behaviour and environments can be contained within peatlands. These may take the form of human artefacts, or palaeoecological and geochemical records. Peatlands are used by humans in modern times for a range of purposes, the most dominant being agriculture and forestry, which accounts for around

2812-484: The draining of peat bogs release even more carbon dioxide. The economic value of a tropical peatland was once derived from raw materials, such as wood, bark, resin and latex, the extraction of which did not contribute to large carbon emissions. In Southeast Asia, peatlands are drained and cleared for human use for a variety of reasons, including the production of palm oil and timber for export in primarily developing nations. This releases stored carbon dioxide and preventing

2886-406: The ecosystem can undergo a state shift, turning the mire into a barren land with lower biodiversity and richness. The formation of humic acid occurs during the biogeochemical degradation of vegetation debris, animal residue and degraded segments. The loads of organic matter in the form of humic acid is a source of precursors of coal. Prematurely exposing the organic matter to the atmosphere promotes

2960-478: The emission of methane, which is a strong greenhouse gas. However, given the short "lifetime" of methane (12 years), it is often said that methane emissions are unimportant within 300 years compared to carbon sequestration in wetlands. Within that time frame or less, most wetlands become both net carbon and radiative sinks. Hence, peatlands do result in cooling of the Earth's climate over a longer time period as methane

3034-628: The environment and can reveal levels of isotopes , pollutants, macrofossils , metals from the atmosphere and pollen. For example, carbon-14 dating can reveal the age of the peat. The dredging and destruction of a peatland will release the carbon dioxide that could reveal irreplaceable information about the past climatic conditions. Many kinds of microorganisms inhabit peatlands, due to the regular supply of water and abundance of peat forming vegetation. These microorganisms include but are not limited to methanogens , algae, bacteria, zoobenthos , of which Sphagnum species are most abundant. Peat contains

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3108-591: The genus Sphagnum . This moss is critical in bogs for its ability to absorb and retain moisture and nutrients from the atmosphere, and to retard vascular plant growth, thus contributing to carbon (C) sequestration . Atmospheric N deposition in North America is lower than in Europe. Studies in boreal peatlands in Canada have reported a positive correlation between wet N deposition and C accumulation, but it

3182-485: The global carbon cycle . In their natural state, peatlands provide a range of ecosystem services , including minimising flood risk and erosion, purifying water and regulating climate. Peatlands are under threat by commercial peat harvesting, drainage and conversion for agriculture (notably palm oil in the tropics) and fires, which are predicted to become more frequent with climate change . The destruction of peatlands results in release of stored greenhouse gases into

3256-448: The land selected for plantations are typically substantial carbon stores that promote biodiverse ecosystems. Palm oil plantations have replaced much of the forested peatlands in Southeast Asia. Estimates now state that 12.9 Mha or about 47% of peatlands in Southeast Asia were deforested by 2006. In their natural state, peatlands are waterlogged with high water tables making for an inefficient soil. To create viable soil for plantation,

3330-752: The largest area of peatlands, and contains the largest peatland in the world, The Great Vasyugan Mire . Nakaikemi Wetland in southwest Honshu, Japan is more than 50,000 years old and has a depth of 45 m. The Philippi Peatland in Greece has probably one of the deepest peat layers with a depth of 190 m. According to the IPCC Sixth Assessment Report , the conservation and restoration of wetlands and peatlands has large economic potential to mitigate greenhouse gas emissions, providing benefits for adaptation, mitigation and biodiversity. Wetlands provide an environment where organic carbon

3404-400: The largest natural carbon store on land. Covering around 3 million km globally, they sequester 0.37 gigatons (Gt) of carbon dioxide (CO 2 ) a year. Peat soils store over 600 Gt of carbon, more than the carbon stored in all other vegetation types, including forests. This substantial carbon storage represents about 30% of the world's soil carbon , underscoring their critical importance in

3478-645: The largest peatlands in the world, with an area of about 24 million hectares. These peatlands play an important role in global carbon storage and have very high biodiversity. However, peatlands in Indonesia also face major threats from deforestation and forest fires. In the early 21st century, the world's largest tropical mire was found in the Central Congo Basin , covering 145,500 km and storing up to 10 kg of carbon. The total area of mires has declined globally due to drainage for agriculture, forestry and peat harvesting. For example, more than 50% of

3552-484: The last Ice Age), and above 25 m in tropical regions. When the absolute decay rate of peat in the catotelm (the lower, water-saturated zone of the peat layer) matches the rate of input of new peat into the catotelm, the mire will stop growing in height. Despite accounting for just 3% of Earth's land surfaces, peatlands are collectively a major carbon store containing between 500 and 700 billion tonnes of carbon. Carbon stored within peatlands equates to over half

3626-420: The litter and peat via heterotrophic respiration. In their natural state, mires are a small atmospheric carbon dioxide sink through the photosynthesis of peat vegetation, which outweighs their release of greenhouse gases. On the other hand, most mires are generally net emitters of methane and nitrous oxide. Due to the continued CO 2 sequestration over millennia, and because of the longer atmospheric lifespan of

3700-575: The littoral zones and deltas of salty water, followed inland by swamp forests . These forests occur on the margin of peatlands with a palm rich flora with trees 70 m tall and 8 m in girth accompanied by ferns and epiphytes. The third, padang , from the Malay and Indonesian word for forest, consists of shrubs and tall thin trees and appear in the center of large peatlands. The diversity of woody species, like trees and shrubs, are far greater in tropical peatlands than in peatlands of other types. Peat in

3774-467: The main challenges is the infrequent sample intervals and the lack of chemical data on surface peat or sufficient information on habitat conditions. Although some nutrient release occurs in ombrotrophic peat, there is a significant gap in understanding the rate and depth of element release and how mobility varies within these ecosystems. Therefore, despite the recognition of their importance, ombrotrophic bogs remain relatively understudied , highlighting

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3848-416: The mid-1800s, peaked between 1950 and 1960, and may have declined thereafter. Preindustrial deposition levels were estimated to be about 4 μg/m per year, while recent deposition levels were approximately 19 μg/m per year. The deposition of mercury in Arlberg Bog appeared to have been influenced by both regional and/or local-scale sources, highlighting the complex nature of atmospheric deposition patterns and

3922-470: The mires in tropical regions of Indonesia and Malaysia are drained and cleared. The peatland forests harvested for palm oil production serve as above- and below-ground carbon stores, containing at least 42,069 million metric tonnes (Mt) of soil carbon. Exploitation of this land raises many environmental concerns, namely increased greenhouse gas emissions , risk of fires and a decrease in biodiversity. Greenhouse gas emissions for palm oil planted on peatlands

3996-439: The need to consider multiple factors when studying metal deposition in ombrotrophic bogs. However, despite their significance as sources of fuel and horticultural peat moss, there is still much to uncover about the ecological and biogeochemical processes of ombrotrophic bogs. Chemical analyses of peat profiles could shed light on this aspect, but the data collected so far have not been adequate for such analysis. One of

4070-826: The original European mire area which is more than 300,000 km has been lost. Some of the largest losses have been in Russia, Finland, the Netherlands, the United Kingdom, Poland and Belarus. A catalog of the peat research collection at the University of Minnesota Duluth provides references to research on worldwide peat and peatlands. Peatlands have unusual chemistry that influences, among other things, their biota and water outflow. Peat has very high cation-exchange capacity due to its high organic matter content: cations such as Ca are preferentially adsorbed onto

4144-402: The other hand, is linked to poverty and is so widespread that it also has negatively impacts these peatlands. The biotic and abiotic factors controlling Southeast Asian peatlands are interdependent. Its soil, hydrology and morphology are created by the present vegetation through the accumulation of its own organic matter, building a favorable environment for this specific vegetation. This system

4218-408: The peat in exchange for H ions. Water passing through peat declines in nutrients and pH . Therefore, mires are typically nutrient-poor and acidic unless the inflow of groundwater (bringing in supplementary cations) is high. Generally, whenever the inputs of carbon into the soil from dead organic matter exceed the carbon outputs via organic matter decomposition , peat is formed. This occurs due to

4292-516: The peatland, and allowing natural vegetation to recover. Rehabilitation projects undertaken in North America and Europe usually focus on the rewetting of peatlands and revegetation of native species. This acts to mitigate carbon release in the short term before the new growth of vegetation provides a new source of organic litter to fuel the peat formation in the long term. UNEP is supporting peatland restoration in Indonesia. Peat extraction

4366-436: The peatlands and the atmosphere has been of current concern globally in the field of ecology and biogeochemical studies. The drainage of peatlands for agriculture and forestry has resulted in the emission of extensive greenhouse gases into the atmosphere, most notably carbon dioxide and methane. By allowing oxygen to enter the peat column within a mire, drainage disrupts the balance between peat accumulation and decomposition, and

4440-414: The planet's 2500 Gt soil carbon stores. Peatlands contain the highest amounts of soil organic carbon of all wetland types. Wetlands can become sources of carbon, rather than sinks, as the decomposition occurring within the ecosystem emits methane. Natural peatlands do not always have a measurable cooling effect on the climate in a short time span as the cooling effects of sequestering carbon are offset by

4514-463: The project was abandoned in 1999. Similar projects in China have led to immense loss of tropical marshes and fens due to rice production. Drainage, which also increases the risk of burning, can cause additional emissions of CO 2 by 30–100 t/ha/year if the water table is lowered by only 1 m. The draining of peatlands is likely the most important and long-lasting threat to peatlands globally, but

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4588-412: The risk of fires, presenting further risk of carbon and methane to release into the atmosphere. Due to their naturally high moisture content, pristine mires have a generally low risk of fire ignition. The drying of this waterlogged state means that the carbon-dense vegetation becomes vulnerable to fire. In addition, due to the oxygen deficient nature of the vegetation, the peat fires can smolder beneath

4662-425: The slow rate of accumulation of dead organic matter, and often contain permafrost and palsas . Very large swathes of Canada, northern Europe and northern Russia are covered by boreal mires. In temperate zones mires are typically more scattered due to historical drainage and peat extraction, but can cover large areas. One example is blanket bog where precipitation is very high i.e., in maritime climates inland near

4736-602: The subsequent oxidative degradation results in the release of carbon into the atmosphere. As such, drainage of mires for agriculture transforms them from net carbon sinks to net carbon emitters. Although the emission of methane from mires has been observed to decrease following drainage, the total magnitude of emissions from peatland drainage is often greater as rates of peat accumulation are low. Peatland carbon has been described as "irrecoverable" meaning that, if lost due to drainage, it could not be recovered within time scales relevant to climate mitigation. When undertaken in such

4810-596: The surface causing incomplete combustion of the organic matter and resulting in extreme emissions events. In recent years, the occurrence of wildfires in peatlands has increased significantly worldwide particularly in the tropical regions. This can be attributed to a combination of drier weather and changes in land use which involve the drainage of water from the landscape. This resulting loss of biomass through combustion has led to significant emissions of greenhouse gasses both in tropical and boreal/temperate peatlands. Fire events are predicted to become more frequent with

4884-737: The surrounding landscape, and since rain is acidic and very low in nutrients , they are home to organisms tolerant of acidic, low-nutrient environments. The vegetation of ombrotrophic peatlands is often bog , dominated by Sphagnum mosses. The hydrology of these environments are directly related to their climate , as precipitation is the water and nutrient source, and temperatures dictate how quickly water evaporates from these systems. Ombrotrophic circumstances may occur even in landscapes composed of limestone or other nutrient-rich substrates – for example, in high-rainfall areas, limestone boulders may be capped by acidic ombrotrophic bog vegetation. Epiphytic vegetation (plants growing on other plants)

4958-476: The system from sequestering carbon again. The global distribution of tropical peatlands is concentrated in Southeast Asia where agricultural use of peatlands has been increased in recent decades. Large areas of tropical peatland have been cleared and drained for the production of food and cash crops such as palm oil. Large-scale drainage of these plantations often results in subsidence , flooding, fire and deterioration of soil quality . Small scale encroachment on

5032-437: The term quagfen. Some swamps can also be peatlands (e.g.: peat swamp forest ), while marshes are generally not considered to be peatlands. Swamps are characterized by their forest canopy or the presence of other tall and dense vegetation like papyrus . Like fens, swamps are typically of higher pH level and nutrient availability than bogs. Some bogs and fens can support limited shrub or tree growth on hummocks . A marsh

5106-842: The tropics is therefore dominated by woody material from trunks of trees and shrubs and contain little to none of the sphagnum moss that dominates in boreal peatlands. It's only partly decomposed and the surface consists of a thick layer of leaf litter. Forestry in peatlands leads to drainage and rapid carbon losses since it decreases inputs of organic matter and accelerate the decomposition. In contrast to temperate wetlands, tropical peatlands are home to several species of fish. Many new, often endemic, species has been discovered but many of them are considered threatened. The tropical peatlands in Southeast Asia only cover 0.2% of Earth's land area but CO 2 emissions are estimated to be 2 Gt per year, equal to 7% of global fossil fuel emissions. These emissions get bigger with drainage and burning of peatlands and

5180-436: The warming and drying of the global climate. The United Nations Convention on Biological Diversity highlights peatlands as key ecosystems to be conserved and protected. The convention requires governments at all levels to present action plans for the conservation and management of wetland environments. Wetlands are also protected under the 1971 Ramsar Convention . Often, restoration is done by blocking drainage channels in

5254-467: The water table falls lower, such as during a drought, as this increases the availability of oxygen to the aerobic microbes thus accelerating peat decomposition. Levels of methane emissions also vary with the water table position and temperature. A water table near the peat surface gives the opportunity for anaerobic microorganisms to flourish. Methanogens are strictly anaerobic organisms and produce methane from organic matter in anoxic conditions below

5328-584: The water table level, while some of that methane is oxidised by methanotrophs above the water table level. Therefore, changes in water table level influence the size of these methane production and consumption zones. Increased soil temperatures also contribute to increased seasonal methane flux. A study in Alaska found that methane may vary by as much as 300% seasonally with wetter and warmer soil conditions due to climate change. Peatlands are important for studying past climate because they are sensitive to changes in

5402-596: The wetlands through native brush and into the Mataura river. It is a small sanctuary for the declining native fresh water fish population. Intensive farming in the catchment for the wetland has raised fears that the Waituna Lagoon , which is a part of the wetland, may soon begin to suffer from eutrophication . Peatland The formation of peatlands is primarily controlled by climatic conditions such as precipitation and temperature, although terrain relief

5476-513: The world's largest crops. In comparison to alternatives, palm oil is considered to be among the most efficient sources of vegetable oil and biofuel , requiring only 0.26 hectares of land to produce 1 ton of oil. Palm oil has therefore become a popular cash crop in many low-income countries and has provided economic opportunities for communities. With palm oil as a leading export in countries such as Indonesia and Malaysia, many smallholders have found economic success in palm oil plantations. However,

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