Study reveals Congo swamps as the worlds largest tropical peatland

A vast peatland in the Congo Basin has been mapped for the first time, revealing it to be largest in the tropics. 

The new study, which involved researchers from our University, found the Cuvette Centrale peatlands in the central Congo Basin cover 145,500 square kilometres – an area larger than England. They lock in 30 billion tonnes of carbon making the region one of the most carbon-dense ecosystems on Earth.

The UK-Congolese research team spent three years exploring remote tropical swamp forests to find samples of peat for laboratory analysis. Their research, published in Nature, combined the peat analysis with satellite imagery to estimate that the Congo Basin peatlands store the equivalent to three years of the world’s total fossil fuel emissions.

Professor Susan Page from the Department of Geography, who co-led the study, said: “Tropical peatland is one of Earth’s largest and most efficient carbon sinks. Development of tropical peatland for agriculture and plantations removes the carbon sink capacity of the peatland system with large carbon losses arising particularly from enhanced peat degradation and the loss of any future carbon sequestration by the native peat swamp forest vegetation.” 

The study places the Democratic Republic of Congo (DRC) and the Republic of Congo (RoC) as the second and third most important countries in the world for tropical peat carbon stocks. In first place is Indonesia, as it contains the tropical peatlands across the islands of, Borneo, Sumatra and New Guinea.

But, as Professor Page explains: “Tropical peatlands in Indonesia are a globally important store of soil carbon but they are under enormous pressure from plantation and other forms of agricultural development which is leading to very high emissions of carbon dioxide, a greenhouse gas, into the atmosphere.”

The researchers used data from US and Japanese satellites to map the two specific peat swamp forest types across the whole region to determine the boundaries of the Congo Basin peatlands. About 40% of the total extent of all the Cuvette Centrale wetlands has peat underneath. Combining this area with peat depth and peat carbon content from the laboratory analyses allowed the total carbon stocks to be calculated. The Cuvette Centrale peatland carbon stock estimate is 10 times higher than the previously published estimate.