Peat in Lewis, ScotlandPeat is an accumulation of partially decayed vegetable matter. Peat forms in wetlands or peatlands, variously called bogs, moors, muskegs, mires, and fens.
1 Geographic distribution
Peat deposits are found in many places around the world, notably in Ireland, Scotland, northern Germany and Scandinavia, and in North America principally in Canada, Michigan and the Florida EvergladesThe Florida Everglades is a subtropical marshland located in the southern portion of the U. state of Florida, specifically in parts of Monroe, Collier, Palm Beach, Miami-Dade, and Broward counties. Although much modified by agricultural development in cen. The majority (around 80%) of peatlands are found in high latitudes; approximately 60% of the world's wetlands are peat. Peatlands cover a total of around 3% of global land mass or 3,850,000 to 4,100,000 kmē. About 7% of this total has been exploited for agriculture and forestry, with significant environmental repercussions.
2 Peat formation
Peat forms when plant material, usually in marshy areas, is inhibited from decaying fully by acidic conditions. It is composed mainly of peat moss or sphagnumSphagnum is a genus of mosses commonly called peat moss due to its prevalence in peat bogs. Members of this genus can hold large quantities of water inside their cells; some species can hold up to 20 times their dry weight in water, which is why peat moss, but may also include trees, grasses and other marshland vegetation. It also includes many other types of organic remains, including fungi, insectSubclass Apterygota Symphypleona globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura extinct Thysanura (common bristletails) Subclass Pterygota Palaeodictyoptera extinct Ephemeroptera (mayflies) Odonata ( dragonfls, pollenSEM image of pollen grains from a variety of common plants: sunflower Helianthus annuus , morning glory Ipomea purpurea ,hollyhock Sildalcea malviflora , lily Lilium auratum , primrose Oenothera fruticosa , and castor bean Ricinus communis . Pollen is a f and even, on occasion, human corpses. Its growth and degree of decomposition (or humification) depends principally on its composition and on the degree of waterlogging. Peat formed in very wet conditions will grow considerably faster, and be less decomposed, than that in drier places. This allows climatologistsClimatology is the science that studies climates and investigates their phenomena and causes. The discipline also referred to as climate research. A climatologist is someone who studies climatology. The study of climatology involves weather information sh to use peat as an indicator of climatic change. The composition of peat can also be used to reconstruct ancient ecologies by examining the types and quantities of its organic elements.
Under the right conditions, peat is the earliest stage in the formation of coalCoal is a fossil fuel extracted from the ground by mining. It is a readily combustible black or brownish-black sedimentary rock. It is composed primarily of carbon and hydrocarbons, along with assorted other elements, including sulfur. Often associated wi. Most modern peat bogs formed in high latitudes after the retreat of the glaciers at the end of the last ice ageFor the animated movie, see Ice Age (movie . For the band, see Ice Age (band . An ice age is a period of long-term downturn in the temperature of Earth's climate, resulting in an expansion of the polar ice caps and mountain glaciers (" glaciation"). Glaci some 9,000 years ago. They usually grow very slowly, at the rate of only about a millimetre per year.
3 Types of peatland
Six principal types of peatland are widely recognised. These are:
- Blanket mires. Rain-fed peatlands generally 1 to 3 m deep. Many of the peatlands found in the United Kingdom are of this type, with the UK possessing around 13% of the total global blanket mire area. They generally develop in cool climates with small seasonal temperature fluctuations and over 1 m of rainfall and over 160 rain days each year.
- Raised mires: Rain-fed, potentially deep peatlands occurring principally in lowland areas across much of Northern Europe, as well as in the former USSR, North America and parts of the southern hemisphere.
- String mires: flat or concave peatlands with a string-like pattern of hummocks (hence the name), found principally in northern Scandinavia but occurring in the western parts of the former USSR and in North America. A few examples exist in northern Britain.
- Tundra mires: peatlands with a shallow peat layer, only about 500 mm thick, dominated by sedges and grasses. They form in permafrost areas, covering around 110,000 to 160,000 kmē in Alaska, Canada, and the former USSR.
- Palsa mires: a type of peatland typified by characteristic high mounds, each with a permanently frozen core, with wet depressions between the mounds. These develop where the ground surface is only frozen for part of the year, and are common in the former USSR, Canada and parts of Scandinavia.
- Peat swamps: forested peatlands including both rain- and groundwater-fed types, commonly recorded in tropical regions with high rainfall. This type of peatland covers around 350,000 kmē, primarily in south-east Asia but also occurring in the Everglades in Florida.
