Peatlands are wetlands primarily consisting of peat. These waterlogged ecosystems are found across the globe, from the chilly expanses of the Northern Hemisphere to the humid tropics, and they play a significant role in the planet’s ecological balance. Despite covering only about 3% of the Earth’s land surface, their importance is substantial.
What Are Peatlands?
Peatlands are wetlands where waterlogged conditions impede the complete decomposition of dead plant material. This slow decay, occurring in environments with low oxygen and high acidity, leads to the gradual accumulation of partially decomposed organic matter, forming layers of peat over thousands of years. The formation of peat is influenced by factors such as precipitation, temperature, and terrain, with flatter areas and basins being more prone to waterlogging.
These ecosystems can begin forming through various processes, including the paludification of mineral soil forests or the terrestrialization of lakes. Peatlands are broadly categorized into bogs and fens, which differ in their water and nutrient sources. Bogs receive water and nutrients solely from rainfall, making them acidic and nutrient-poor, while fens are influenced by nutrient-rich groundwater. Globally, about 64% of peatlands are found in the temperate, boreal, and subarctic zones of the Northern Hemisphere, including Canada, northern Europe, and Russia. Tropical peatlands, making up about 11% of the global total, are primarily found in Southeast Asia, the Congo Basin, and the Amazon basin.
The Role of Peatlands
Peatlands serve as significant carbon sinks, storing more carbon than all other vegetation types combined, including forests. Peat soils globally hold over 600 gigatons of carbon, representing approximately 30% of the world’s soil carbon. In their natural, wet state, these ecosystems actively sequester about 0.37 gigatons of carbon dioxide annually, making them a significant component in regulating the global carbon cycle.
Peatlands are also important for water regulation. They act like natural sponges, absorbing and filtering water, which helps minimize flood risks and mitigate droughts. This hydrological function contributes to water purification, ensuring clean water availability. Peatlands also support unique biodiversity, providing habitat for specialized plant and animal species adapted to their acidic and waterlogged conditions, as seen in regions like the Congo Basin, which hosts one of the world’s largest tropical peatland complexes, supporting distinct ecosystems.
Threats and Conservation
Peatlands face significant threats, primarily from human activities that alter their natural waterlogged state. Drainage for agriculture, forestry, and urban development is a leading cause of degradation, exposing carbon-rich peat to oxygen and accelerating decomposition, which releases greenhouse gases. This drainage affects approximately 15% of global peatlands, converting them from carbon sinks into sources of emissions; drained peatlands are responsible for about 4% to 5% of global anthropogenic greenhouse gas emissions.
Peat extraction for fuel and horticulture also contributes to peatland degradation. Climate change further exacerbates these threats through increased temperatures and altered precipitation patterns, which can dry out peatlands and make them more susceptible to wildfires. Peatland fires, especially in drained areas, can release significantly more greenhouse gases than typical forest fires. The loss of these ecosystems not only contributes to climate change but also leads to land subsidence, increased flooding, and biodiversity loss.
Conservation and restoration efforts are underway to address these challenges. Rewetting drained peatlands is a primary strategy, aiming to re-establish water levels and promote the regrowth of peat-forming vegetation. Organizations like Wetlands International have supported projects globally, rewetting thousands of hectares to prevent fires and restore biodiversity. Sustainable land management practices, such as paludiculture—agriculture adapted to wet conditions—are also being promoted as alternatives to drainage-based land use. Policy efforts, including incorporating peatland protection and restoration into national climate commitments, are advancing to safeguard these ecosystems.