Peaty soil

Peat (/piːt/), also called turf (/tɜːrf/), is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem is the most efficient carbon sink on the planet because peatland plants capture the CO₂ which is naturally released from the peat; this maintains 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 1.5 to 2.3 m [4.9 to 7.5 ft], which is the average depth of the boreal [northern] peatlands".Sphagnum moss (peat moss) is one of the most common components in peat, although many other plants can contribute. Soils that contain mostly peat are known as histosols. Peat forms in wetland conditions, where flooding obstructs flows of oxygen from the atmosphere. This slows rates of decomposition.

Peatlands, particularly bogs, are the most important source of peat. That said, other less common wetland types, including fens, pocosins, and peat swamp forests, also deposit peat. Landscapes covered in peat are home to specific kinds of plants including Sphagnum moss, ericaceous shrubs, and sedges (see bog for more information on this aspect of peat). Because organic matter accumulates over thousands of years, peat deposits also provide records of past vegetation and climates stored in plant remains like pollen. This allows humans to reconstruct past environments and study changes in human land use.

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