Areas with peat soils are called peatlands. The thickness of the peat layer varies per location, but in South-east Asia it can reach up to 25 meters. As the key feature of these wetlands (peat) is located underground, peatlands are often overlooked.

What is Peat?

Peat is dead organic material that has been formed on the spot. Peat consists of 90%  water and 10%  plant matter. Peat is formed under conditions were dead plant material is conserved for thousands of years due to a combination of permanent water saturation, low oxygen levels and a high levels of acidity.

Where are Peatlands found?

Peatlands are found in almost every country  in the world. They cover over 4 million km2 worldwide, or 3% of the world’s total land area, and represent half of the Earth's wetland areas. The largest areas are found in the cold tundra regions of Northern Russia and Canada: these are called boreal peatlands. Southeast Asia contains the largest areas of tropical peatlands. Tropical lowland peatlands were originally covered by dense rainforest. (Click on the map to enlarge)

What are the different types of Peatlands?

Peatlands may be naturally forested or naturally open and vegetated with mosses, sedges or shrubs.

Examples of naturally forested peatlands are the Alder peat forests in Europe and the lowland humid tropical peatswamp forests in Southeast Asia. Tropical peatlands are widely distributed throughout the world. Small tracts are found in parts of Latin America, Africa and the Caribbean. The vast majority, however, is found in South-east Asia, covering 60% of the total tropical peatland area and over 85% of tropical peatland carbon storage.

Examples of naturally open peatlands are the permafrost areas of Russia and Canada, the Everglades in North America, and the high mountain peatlands (Paramos) of the Andes and Himalayas.

What is the importance of Peatlands? 
 

Carbon storage

Peatlands contain globally at least 550 Gigatonnes of carbon: equivalent to all other terrestrial biomass (forests, grass and shrublands, etc.) and twice as much as all carbon stored in the world’s forests.

In the sub (polar) zone, peatlands contain on average 3.5 times more carbon per hectare than above-ground ecosystems on mineral soil; in the boreal zone 7 times more; and in the humid tropics over 10 times the amount of carbon stored in above-ground habitats.

Water retention

Due to their capacities to store and maintain large quantities of water, peatswamp forests play an important role in flood mitigation and ensure a continuous supply of clean water throughout the year. Mountain peatlands,  for example in the Himalayas, Tibetan Plateau and the Andes, play a crucial role in reducing extremes in water flow and reducing floods or droughts. The Paramos are called the "Water Towers" of the Andes because of their value for water supply.

Biodiversity

Peat soils often possess very nutrient-poor soils, and tend to be the poorest areas for agriculture. Although the total species richness in peatlands in temperate climates is low, they are the only available habitat for many endemic plant and animal species.

Tropical peat swamp forests represent, despite the lack of nutrients, a very high biodiversity ecosystem with thousands of species, including many endemics, rare and endangered species. The black peat waters support the highest density of freshwater biodiversity of the world.

Agriculture and forestry, fisheries

Peatlands are very poor agricultural areas and generally support only low population densities. Despite this, millions of people live in and depend on the world’s peatlands for their livelihoods. These include herding cattle, catching fish,  harvesting reeds, farming specific crops and, in forested peatlands, forestry and collection of many valuable non-timber forest products.

Efforts to improve the agricultural production of peatlands by conversion, drainage and fertilizing the soils are generally unsuccessful and very unsustainable. These areas often turn into wastelands within decades when as a result of soil subsidence they become prone to long periods of inundation. Many tropical peatlands are underlain by potential acid sulphate soils which become active when drainage levels become too deep, causing severe acidification of the area and its surroundings. Drainage also causes significant increase of fire risks.

What is the state of the world’s peatlands?

Human exploitation has destroyed 25% of the peatlands on earth.

The enormous peatlands of Northern America or Russia are often as yet still relatively unaffected. However in many countries in Europe and Central Asia peatlands have been severely affected by agriculture and mining.  Even if degraded, decomposition processes in the cold northern peatlands and southern peatlands of Argentina or Chile take place at a much slower rate than in the tropics.

What happens if we would lose the world’s peatlands?

In particular the magnitude of the loss of the boreal peatlands in Canada or Russia is enormous. If these are degraded, global greenhouse gas emissions would rise dramatically as these areas currently store over 50 times more carbon than all annual anthropogenic fossil fuel emissions.

Of even greater concern is that the threat of climate change on peatlands themselves is alarming forms a vicious circle. Climate change driven by global warming could lead to degradation of the peatland areas and in turn lead to massive emissions of carbon from the organic peat. If the melting of the permafrost of Canada and Russia becomes a reality, large peatland areas will 'come out of the fridge’ and decompose during summer periods resulting in enormous CO2 emissions.

In addition, the combination of relatively young (seasonal) vegetation and temporary flooding leads in boreal peatlands to production of methane- a very potent greenhouse gas. There is also a risk that fossilised methane, stored under the permafrost areas, could be released.