Over the past three years the University of Edinburgh has participated in a collaborative research project between universities in the UK and the Republic of Congo to map the world’s largest tropical peatlands.
Preventing the destruction of the peatlands – situated in the Cuvette Centrale depression that extends across the border between the Republic of Congo and the Democratic Republic of Congo – plays a significant role in the fight to combat global warming.
The research team, led by Dr Greta Dargie and Dr Simon Lewis of the University of Leeds, included academics from University College London, the Universities of St Andrews, Edinburgh and Leicester, and the Université Marien Ngouabi in Brazzaville.
A paper that summarises their findings has been published in the journal, Nature.
The research team discovered that the peat deposit covers a distance of 145,500 square kilometres at a median depth of about two metres.
Using data gathered over three trips to the Republic of Congo it has been estimated that the area can store approximately 30.6 petagrams of carbon.
This increases global peatland carbon stocks by an estimated 36 per cent.
Dr Edward Mitchard, who co-authored the article and is based at the University of Edinburgh’s School of Geoscience, expressed his surprise at the team’s findings: “[The results] were definitely at the upper end of the area we had expected,” he told The Student.
“When we first went to the area in 2011 we didn’t even know if we’d find any peat at all. We thought we might find some, but maybe just some small patches: instead we found an area bigger than England.”
In an interview with The Student, co-leader of the project, Dr Greta Dargie, suggested that the lack of data previously gathered in these areas was due to the remoteness of the peatlands.
“The peatlands have been overlooked for so long. Logistically [they are] quite difficult to get to, and the swamps are quite an inhospitable environment.”
“It’s very hard to do science in these areas,” he told The Student: “You have to camp on platforms you build, and travel around by boat or by walking/wading through the mud.”
“[It is a] very challenging place to work,” echoed Dr Mitchard.
The team’s findings, which contributed towards Dr Dargie’s PhD, were made with the assistance of local residents.
Their data was collected using a combination of in situ mapping and remotely gathered figures. The project was the first of its kind to estimate the size of the peatlands using ground data.
The Cuvette Centrale peatlands, home to a diverse ecosystem including lowland gorillas, elephants and chimpanzees, harness carbon that would otherwise be released into the atmosphere as a result of the decomposition of plant matter.
“When organic matter is deposited in the peatlands they cannot fully decompose because they are waterlogged. Normally [it is] very acidic [and] this prevents the micro-organisms from breaking down the organic matter” Dr Dargie explained to The Student. “The carbon does not get released as carbon dioxide into the atmosphere [and] the plant material isn’t completely decomposed so that carbon stays in the soil.”
“Discovering more [peatland] is not a positive thing for climate change – we’ve discovered a massive further source of carbon that could be released to the atmosphere,” Dr Mitchard stated.
“This could occur over the next 50 to 100 years in response to rising temperatures and changing rainfall patterns – even if we leave it alone. If you warm up peat, it decomposes.
“Increased levels of carbon dioxide in the atmosphere will contribute to global warming,” he told The Student.
To counter the effect an increase in the global temperature could have on the peatlands, Dr Dargie called for the international community to reduce their greenhouse gas emissions.
The peatlands are located underneath swamp forest vegetation in the forested wetlands. The ground is fully submerged in water for part of the year.
Dr Dargie suggested that it may be this isolation that has protected the peatlands from destruction: “At present the peatlands are fairly intact” she told The Student, “but that should be seen as an opportunity to make sure what happens in South-East Asia doesn’t happen in the Congo.”
“Peatlands, especially in South-East Asia, have undergone considerable degradation and destruction because of palm oil plantation, other deforestation and industrial agriculture” said Dr Dargie.
“We are already working with DRC and RC to extend national parks to include these areas,” Dr Mitchard reported.
In addition to this action, Dr Mitchard said: “The developed world needs really to provide funding for this protection, and for alternative development opportunities to local people. It’s in the whole world’s interest for these peats to stay protected, and the rich world should pay, not these two countries which are among the world’s poorest.”
Image: Simon Lewis