A peatland is a type of wetland whose soils consist of organic matter from decaying plants, forming layers of peat. Peatlands arise because of incomplete decomposition of organic matter, usually litter from vegetation, due to water-logging and subsequent anoxia. Like coral reefs, peatlands are unusual landforms that derive mostly from biological rather than physical processes, and can take on characteristic shapes and surface patterning.
A variety of mire types in Carbajal Valley, Argentina
Avaste Fen, one of the largest fens in Estonia
A valley mire creates a level ground surface in otherwise dramatic topography. Upper Bigo Bog, Rwenzori Mountains, Uganda.
Extraction of peat from derelict blanket bog, South Uist, Scotland. This old bog is no longer forming peat because the vegetation has been changed, and therefore it is not a mire.
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently for years or decades or seasonally for a shorter periods. Flooding results in oxygen-free anoxic processes prevailing, especially in the soils. 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. 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. 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.
Marshlands are often noted within wetlands, as seen here at the Jamaica Bay Wildlife Refuge in New York City.
Sunrise at Viru Bog, Estonia
Wetlands contrast the hot, arid landscape around Middle Spring, Fish Springs National Wildlife Refuge, Utah
Humid wetland in Pennsylvania before a rain.