We recently discovered the world's largest tropical peatland complex, spanning an area larger than England, in the heart of Africa. This proposal brings together an interdisciplinary team of scientists to study this newly discovered ecosystem. Our goal is to understand how the peatland became established, how it functions today, and how it will respond to human-induced climate change and differing future development pathways. We will use the results to inform critical policy decisions about the region. Peat is partially decomposed plant matter.
Peatlands are some of the most carbon-dense ecosystems on Earth. Covering 3% of Earth's land surface, they store one-third of soil carbon. A recent NERC-funded PhD, led by CongoPeat PI Professor Lewis, showed for the first time that the largest wetland in Africa, in the central Congo Basin, contains extensive peat deposits. This research, published in 2017 in Nature, estimates that the peatland stores 30 billion tonnes of carbon (C). By comparison, in 2016, UK emissions were 0.1 billion tonnes of C. Our discovery increases global tropical peatland C stocks by 36%.
We know very little about this new globally important ecosystem. Our data show peat accumulation began about 10,600 years ago, when central Africa's climate became wetter. Accumulation has been slow - on average just 2 m has accumulated over this period - but it is unknown whether this is due to a constant slow build-up of peat and C, or fast rates interspersed with losses in drier periods. Our evidence suggests that the peatlands are fed by rainfall, but such peatlands usually form domes ('raised bogs'), yet satellite data do not show this feature. Thus, we do not know how this peatland system developed, how it functions today, or how vulnerable it is to future climate and land use changes.
Tropical peatlands in SE Asia have been extensively damaged by drainage for industrial agriculture, particularly oil palm, with serious biodiversity, climate and human health implications. Oil palm is now rapidly expanding across Africa. Congolese peatlands could become a globally significant source of atmospheric CO2 if they are drained, leading to their decay. A prerequisite of following a different development pathway is a scientific understanding of the region.
The CongoPeat proposal therefore brings together leading experts from six UK universities, a science-policy communication specialist, and five Congolese partner organisations, to gain:
- An integrated understanding of the origin and development of the central Congo peatland complex over the last 10,000 years. We will analyse peat deposit sequences from across the region, extracting preserved pollen grains, charcoal, and chemical markers, to reconstruct the changing environment through time. We will use an unmanned aerial vehicle to map peatland surface topography, and develop a mathematical model of peatland development.
- A better estimate of the amount of C stored in the peat, its distribution, and the amounts of important greenhouse gases, CO2, methane, and nitrous oxide, being exchanged with the atmosphere. This will be achieved via extensive fieldwork to map peat distribution, and by installing intensive measurement stations to determine the flows of C into and out of the ecosystem.
- An understanding of the possible future scenarios for the Congo peatlands. A range of models will be used to simulate the possible impacts of future climate and land-use change on the peatland, at local to global scales.
Finally, we will effectively communicate these results to policy-makers in Africa and internationally via briefings and active media engagement. The CongoPeat team will produce the first comprehensive assessment of the genesis, development, and future of the world's largest tropical peatland, enabling the UK to retain world-leading expertise in understanding how the Earth functions as an integrated system and how humans are changing it.