Peatlands are lands with a naturally accumulated peat layer at their surface. They are found all over the world and come in many forms, display many different characteristics and are used in many different ways. Even though peatlands extend over a relatively small portion of the earth’s land surface, they hold a large pool of carbon. There is no universal definition of peatlands. For the purpose of assessing emissions, Intergovernmental Panel of Climate Change (IPCC) guidelines included the concept of peatland in the ‘land with organic soil’ category and identify organic soils as histosols. The IPCC guidelines also present emission factors for peatlands under different land uses.
In their natural state, peatlands support a large range of habitats and provide a home for unique biodiversity. Along with storing large quantities of carbon, peatlands also play an important role in the retention, purification and release of water and in the mitigation of droughts and floods. They provide a source for fish, non-timber forest products and other goods and services. Their special characteristics also make peatlands unique space for culture, leisure and education activities. Peat has also been extracted to generate energy and supply growing media to the horticulture industry. Many natural peatlands have been converted and drained to allow for conventional agriculture and forestry.
When drained, peatlands become net sources of greenhouse gas (GHG) emissions. Because of drainage, organic soils are currently the third-largest emitter of GHGs in the Agriculture, Forestry and Land Use (AFOLU) sector; they emit almost one gigatonne of CO2 equivalent (CO2-eq), which represents 10 percent of the total AFOLU emissions. High GHG emissions are particularly evident when oil palm and pulp wood production are carried out under deep drainage and high temperature on tropical peatlands. Peatlands mapping is needed to estimate GHG emissions. However, mapping peatlands is not easy, as there is no generally accepted operational definition for peatlands and the use of remote sensing technologies is made difficult by the fragmented distribution pattern of peatlands and their differentiated land use. The challenge of mapping peatlands is heightened by the inherent environmental problems of conducting ground observations in many peatland areas. A global information system would be required to provide reliable data on peatlands and their management, and to support the identification of appropriate practices for the more responsible use of peatland resources.
Along with increasing GHG emissions, peatland drainage also leads to the lowering the height of the land surface, a process known as land subsidence. Peatland drainage also increases the discharge of carbon as dissolved organic carbon (DOC) and particulate organic carbon (POC) downstream, which reduces water quality in aquatic ecosystems. Over time, peatland drainage causes the vegetation cover to change and biodiversity to be lost. Fires become more frequent. There can be increases in salt water intrusion, droughts and soil erosion, all of which eventually reduce agricultural productivity. Many peatlands that have been drained for agriculture have been abandoned due to a combination of progressive soil degradation, decreasing productivity and increasing costs of drainage. As long as drainage continues, abandoned peatlands will continue to emit GHGs and the land will continue to subside.
To cope with the negative consequences of peatlands unsustainable management, the following steps are recommended:
- Conserve intact peatlands;
- Rewet drained peatlands;
- Apply climate-responsible peatlands management; and
- Implement adaptive management where rewetting is not possible.
The priority is to safeguard and preserve natural peatlands from degradation. Rewetting of already drained peatlands conserves biodiversity, regenerates vegetation, replenishes freshwater resources and reduces GHG emissions. During rewetting, the stabilisation of high water levels can be achieved through hydrological practices that include, enlarging water storage in the peatlands, decreasing water losses and increasing water supply.
Paludiculture (biomass cultivation in wet conditions) can be considered a responsible management option for peatland management. Paludiculture produces biomass from wet and rewetted peatlands under conditions that maintain the peat body, sustain ecosystem services and may facilitate carbon accumulation. Besides producing traditional agricultural commodities such as food, feed, fibre and fuel, paludiculture can also generate other raw materials for a variety of purposes, including industrial biochemistry.
Responsible management practices are also needed where peatlands are used as pastures. Raising the water table, regulating the number of grazing livestock, fencing pastures for rotational grazing and replanting or reseeding of forage species, all help to control soil erosion and reduce off-site water pollution.
In cases when rewetting of drained peatlands is not possible, adaptive management practices that reduce GHG emissions should be adopted. Adaptive management avoids over-drainage, soil tillage and the use of fertilizers. In forestry, a shift towards continuous forest cover and the avoidance of clear-cuts are also recommended. On croplands, permanent crops are the preferred agricultural option. Cultivating fish in the rewetted peatlands to support local economies is a strategy that can potentially preserve existing carbon stores. However, further studies are required to evaluate the impact of aquaculture on the GHG balance and the livelihoods of local communities.
When considering peatland management, it is also essential to address social issues, such as local communities’ access to and use of natural resources. The Participatory Negotiated Territorial Development approach offers a field-tested methodology that focuses on creating an environment of open dialogue, fair negotiation and social legitimacy from the local to the national level to introduce and implement climate-responsible strategies.
To access financing for responsible peatlands management practices and policies, international programmes and mechanisms such as Reducing Emissions from Deforestation and Forest Degradation (REDD+) and Nationally Appropriate Mitigation Actions (NAMAs) can be considered.