Peat is an accumulation of partially Decomposition vegetation or organic matter. It is unique to natural areas called , , , Moorland, or . Sphagnum moss, also called peat moss, is one of the most common components in peat, although many other plants can contribute. The biological features of sphagnum mosses act to create a habitat aiding peat formation, a phenomenon termed 'habitat manipulation'.Walker, M.D. 2019. Sphagnum; the biology of a habitat manipulator. Sicklebrook publishing, Sheffield, U.K. Soils consisting primarily of peat are known as . Peat forms in wetland conditions, where flooding or stagnant water obstructs the flow of oxygen from the atmosphere, slowing the rate of decomposition.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Chapter 1. Peat properties such as organic matter content and saturated hydraulic conductivity can exhibit high spatial heterogeneity.
Peatlands, particularly , are the primary source of peat; although less common, other wetlands, including , and peat swamp forests, also deposit peat. Landscapes covered in peat are home to specific kinds of plants, including Sphagnum moss, Ericaceae shrubs and sedges.See bog for more information on this aspect of peat. Because organic matter accumulates over thousands of years, peat deposits provide records of past vegetation and climate by preserving plant remains, such as pollen. This allows the reconstruction of past environments and the study of .Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge. 497 pp. 323–25
Peat is used by gardeners and for horticulture in certain parts of the world, but this is being banned in some places. By volume, there are about 4 trillion cubic metres of peat in the world. Over time, the formation of peat is often the first step in the geological formation of such as coal, particularly low-grade coal such as lignite. The peatland ecosystem covers and is the most efficient carbon sink on the planet, because peatland plants capture carbon dioxide (CO2) naturally released from the peat, maintaining an equilibrium. In natural peatlands, the "annual rate of biomass production is greater than the rate of decomposition", but it takes "thousands of years for peatlands to develop the deposits of , which is the average depth of the boreal northern peatlands", which store around 415 gigatonnes (Gt) of carbon (about 46 times 2019 global CO2 emissions). Globally, peat stores up to 550 Gt of carbon, 42% of all soil carbon, which exceeds the carbon stored in all other vegetation types, including the world's forests, although it covers just 3% of the land's surface.
Peat is in principle a Renewable energy. However, its extraction rate in industrialized countries far exceeds its slow regrowth rate of per year, and is also reported that peat regrowth takes place only in 30–40% of peatlands. Centuries of burning and draining of peat by humans has released a significant amount of into the atmosphere, contributing to anthropogenic climate change.
Most modern peat formed 12,000 years ago in high latitudes after the glaciers retreated at the end of the last ice age.Vitt, D.H., L.A. Halsey and B.J. Nicholson. 2005. The Mackenzie River basin. pp. 166–202 in L.H. Fraser and P.A. Keddy (eds.). The World's Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge. 488 p. Peat usually accumulates slowly at the rate of about a millimetre per year.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, UK. Cambridge. 497 p. Chapter 7. The estimated carbon content is (northern peatlands), () and (South America).
Phragmites peat are composed of reed grass, Phragmites australis, and other grasses. It is denser than many other types of peat.
Engineers may describe a soil as peat which has a relatively high percentage of organic material. This soil is problematic because it exhibits poor consolidation properties—it cannot be easily compacted to serve as a stable foundation to support loads, such as roads or buildings.
A more recent estimate from an improved global peatland map, PEATMAP, based on a meta-analysis of geospatial information at global, regional and national levels puts global coverage slightly higher than earlier peatland inventories at approximately 2.84% of the world land area. In Europe, peatlands extend to about . IUCN UK Commission of Inquiry on Peatlands Full Report, IUCN UK Peatland Programme October 2011 About 60% of the world's are made of peat.
Peat deposits are found in many places around the world, including northern Europe and North America. The North American peat deposits are principally found in Canada and the Northern United States. Some of the world's largest peatlands include the West Siberian Lowland, the Hudson Bay Lowlands and the Mackenzie River Valley.Fraser, L.H. Fraser and P.A. Keddy (eds.). 2005. The World's Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge, UK. 488 p. and P.A. Keddy (eds.). 2005. The World's Largest Wetlands: Ecology and Conservation. Cambridge University Press, Cambridge, UK. 488 p.
There is less peat in the Southern Hemisphere, in part because there is less land. The world's largest tropical peatland is located in Africa (the Democratic Republic of Congo). In addition, the vast Magellanic Moorland in South America (Southern Patagonia/Tierra del Fuego) is an extensive peat-dominated landscape. Peat can be found in New Zealand, Kerguelen, the Falkland Islands and Indonesia (Kalimantan Sungai, Rasau Jaya (West Kalimantan) and Sumatra). Indonesia has more tropical peatlands and mangrove forests than any other nation on earth, but Indonesia is losing wetlands by per year. A catalog of the peat research collection at the University of Minnesota Duluth provides references to research on worldwide peat and peatlands.
About 7% of all peatlands have been exploited for agriculture and forestry. Under certain conditions, peat will turn into lignite coal over geologic periods of time.
In Quaternary Palaeoecology, first published in 1980, Birks and Birks described how Paleoecology studies "of peat can be used to reveal what plant communities were present (locally and regionally), what period each community occupied, how environmental conditions changed, and how the environment affected the ecosystem in that time and place."
Scientists continue to compare modern mercury (Hg) accumulation rates in bogs with historical natural archives records in peat bogs and lake sediments to estimate the potential human impacts on the biogeochemical cycle of mercury, for example. Over the years, different dating models and technologies for measuring date sediments and peat profiles accumulated over the last 100–150 years, have been used, including the widely used vertical distribution of 210Pb, the inductively coupled plasma mass spectrometry (ICP-SMS), and more recently the initial penetration (IP).
Around half of the area of northern peatlands is permafrost-affected, and this area represents around a tenth of the total permafrost area, and also a tenth (185 ± 66 Gt) of all permafrost carbon, equivalent to around half of the carbon stored in the atmosphere. Dry peat is a good insulator (with a thermal conductivity of around 0.25 Wm−1K−1) and therefore plays an important role in protecting permafrost from thaw. The insulating effect of dry peat also makes it integral to unique permafrost landforms such as and permafrost peat plateaus. Peatland permafrost thaw tends to result in an increase in methane emissions and a small increase in carbon dioxide uptake, meaning that it contributes to the permafrost carbon feedback. Under 2 °C global warming, 0.7 million km2 of peatland permafrost could thaw, and with warming of +1.5 to 6 °C a cumulative 0.7 to 3 PgC of methane could be released as a result of permafrost peatland thaw by 2100. The forcing from these potential emissions would be approximately equivalent to 1% of projected anthropogenic emissions.
One characteristic of peat is the bioaccumulation of metals concentrated in the peat. Accumulated mercury is of significant environmental concern.
Peat has a high carbon content and can burn under low moisture conditions. Once ignited by the presence of a heat source (e.g., a wildfire penetrating the subsurface), it smoulders. These smouldering fires can burn undetected for very long periods of time (months, years, and even centuries) propagating in a creeping fashion through the underground peat layer.
Despite the damage that the burning of raw peat can cause, bogs are naturally subject to wildfires and depend on the wildfires to keep woody competition from lowering the water table and shading out many bog plants. Several families of plants including the carnivorous Sarracenia (trumpet pitcher), Dionaea (Venus flytrap), Utricularia (bladderworts) and non-carnivorous plants such as the sandhills lily, toothache grass and many species of orchid are now threatened and in some cases endangered from the combined forces of human drainage, negligence and absence of fire. toothache-grass www.dmr.state.ms.us
The recent burning of peat bogs in Indonesia, with their large and deep growths containing more than of carbon, has contributed to increases in world carbon dioxide levels. Peat deposits in Southeast Asia could be destroyed by 2040. web link
It is estimated that in 1997, peat and forest fires in Indonesia released between of carbon; equivalent to 13–40 percent of the amount released by global fossil fuel burning, and greater than the carbon uptake of the world's biosphere. These fires may be responsible for the acceleration in the increase in carbon dioxide levels since 1998.Cat Lazaroff, Indonesian Wildfires Accelerated Global Warming , Environment News ServiceFred Pearce Massive peat burn is speeding climate change, New Scientist, 6 November 2004 More than 100 peat fires in Kalimantan and East Sumatra have continued to burn since 1997; each year, these peat fires ignite new forest fires above the ground.
In North America, peat fires can occur during severe droughts throughout their occurrence, from boreal forests in Canada to swamps and fens in the subtropical southern Florida Everglades. Once a fire has burnt through the area, hollows in the peat are burnt out, and hummocks are desiccated but can contribute to Sphagnum recolonization.
In the summer of 2010, an unusually high heat wave of up to ignited large deposits of peat in Central Russia, burning thousands of houses and covering the capital of Moscow with a toxic smog. The situation remained critical until the end of August 2010.
In June 2019, despite some forest fire prevention methods being put in place, peat fires in the Arctic emitted of CO2, which is equal to Sweden's total annual emissions. The peat fires are linked to climate change, as they are much more likely to occur nowadays due to this effect.
In November 2002, the International Peatland (formerly Peat) Society (IPS) and the International Mire Conservation Group (IMCG) published guidelines on the "Wise Use of Mires and Peatlands – Backgrounds and Principles including a framework for decision-making". This publication aims to develop mechanisms that can balance the conflicting demands on the global peatland heritage to ensure its wise use to meet the needs of humankind.
In June 2008, the IPS published the book Peatlands and Climate Change, summarising the currently available knowledge on the topic. In 2010, IPS presented a " Strategy for Responsible Peatland Management", which can be applied worldwide for decision-making.
Peat extraction is forbidden in Chile since April 2024.
Latvia's peat deposits have been estimated to equal 1.7 billion tons. Due to its climate, Latvia has several peat bogs, which account for 9.9% of the country's territory.
More than two thirds of the licensed areas for peat extraction are state-owned; 55% belong to the state whilst 23% belong to the municipalities
Bogs in Latvia are considered important habitats due to their ecological values, and up to 128,000 hectares, or 40% of the areas in the territory, are protected by environmental laws. The most famous national parks and reserves are the Ķemeri National Park, Cenas tīrelis and Teiči Nature Reserve.
Also, agricultural and forestry-drained peat bogs actively release more CO2 annually than is released in peat energy production in Finland. The average regrowth rate of a single peat bog, however, is indeed slow, from 1,000 up to 5,000 years. Furthermore, it is a common practice to forest used peat bogs instead of giving them a chance to renew. This leads to lower levels of CO2 storage than the original peat bog.
At 106 g CO2/Joule, The CO2 emission factor of peat fuel . Imcg.net. accessed on 2011-05-09. the carbon dioxide emissions of peat are higher than those of coal (at 94.6 g CO2/MJ) and natural gas (at 56.1). According to one study, increasing the average amount of wood in the fuel mixture from the current 2.6% to 12.5% would take the emissions down to 93 g CO2/MJ. That said, little effort is being made to achieve this.
The International Mire Conservation Group (IMCG) in 2006 urged the local and national governments of Finland to protect and conserve the remaining pristine peatland ecosystems. This includes the cessation of drainage and peat extraction in intact mire sites and the abandoning of current and planned groundwater extraction that may affect these sites. A proposal for a Finnish peatland management strategy was presented to the government in 2011, after a lengthy consultation phase.
In January 2021, Bord na Móna announced that it had ceased all peat harvesting and cutting operations and would move its business to a climate solutions company.
In 2022, selling peat for burning was prohibited, but some people are still allowed to cut and burn it.
In the 1960s, larger sections of swamps and bogs in Western Russia were drained for agricultural and mining purposes.
In 2020, the Netherlands imported 2,156 million kg of peat (5.39 million m3 400 kg/m3): 44.5% from Germany (2020), 9.5% from Estonia (2018), 9.2% from Latvia (2020), 7.2% from Ireland (2018), 8.0% from Sweden (2019), 6.5% from Lithuania (2020), 5.1% from Belgium (2019) and 1.7% from Denmark (2019); 1.35 million kg was exported.CBS (opendata.cbs.nl), Goederensoorten naar land; minerale brandstoffen en chemie ( tr. "Goods by country; mineral fuels and chemistry") Most is used in gardening and greenhouse horticulture.
Since the Netherlands did not have many trees to use as firewood or charcoal, one use the Dutch made of the available peat was to fire kilns to make pottery.Prins, Marcel & Steenhuis, Peter Henk, "Hidden," Arthur A. Levine Books, New York, 2011, p. 205. During World War II, the Dutch Resistance came up with an unusual use for peat. Since peat was so available in the fields, resistance fighters sometimes stacked peat into human-sized piles and used the piles for target practice.Ibid, p. 204.
The extraction of peat from the Somerset Levels began during the Roman times and has been carried out since the Levels were first drained. On Dartmoor, there were several commercial distillation plants formed and run by the British Patent Naphtha Company in 1844. These produced naphtha on a commercial scale from the high-quality local peat. Dartmoor Peat , Dartmoor history
Fenn's, Whixall and Bettisfield Mosses is an element of a post-Ice Age peat bog that straddles the England–Wales border and contains many rare plant and animal species due to the acidic environment created by the peat. Only lightly hand-dug, it is now a national nature reserve and is being restored to its natural condition.
The industrial extraction of peat occurred at the Thorne Moor site, outside Doncaster near the village of Hatfield. Government policy incentivised commercial removal to peat for agricultural use. This caused much destruction of the area during the 1980s. The removal of the peat resulted in later flooding further downstream at Goole due to the loss of water retaining peatlands.Walker, M. D. Sphagnum. Sicklebrook Press. Recently regeneration of peatland has occurred as part of the Thorne Moors project, and at Fleet Moss, organised by Yorkshire Wildlife Trust.
Because they are easily compressed under minimal weight, peat deposits pose significant difficulties for building structures, roads and railways. When the West Highland railway line was constructed across Rannoch Moor in western Scotland, its builders had to float the tracks on a multi-thousand-ton mattress of tree roots, brushwood, earth and ash.
Formation
Types of peat material
Peatlands distribution
the most widespread of all wetland types in the world, representing 50 to 70% of global wetlands. They cover over or 3% of the land and freshwater surface of the planet. In these ecosystems are found one third of the world's soil carbon and 10% of global freshwater resources. These ecosystems are characterized by the unique ability to accumulate and store dead organic matter from Sphagnum and many other non-moss species, as peat, under conditions of almost permanent water saturation. Peatlands are adapted to the extreme conditions of high water and low oxygen content, of toxic elements and low availability of plant nutrients. Their water chemistry varies from alkaline to acidic. Peatlands occur on all continents, from the tropical to boreal and Arctic zones from sea level to high alpine conditions.
General uses
Fuel
Agriculture
Drinking water
Metallurgy
Flood mitigation
Freshwater aquaria
Balneotherapy
Peat archives
Bog bodies
Environmental and ecological issues
Peat drainage
Peat fires
Erosion: Peat hags
Protection
Restoration
Characteristics and uses by nation
Latvia
Finland
Sweden
Ireland
Russia
Netherlands
Estonia
India
Sikkim
United Kingdom
England
Northern Ireland
Scotland
Wales
Canada
See also
Notes
External links
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