A new study led by CLR researchers Prof Adam Pellegrini and Dr Katy Faulkner has found that clay and silt in drained lowland peat soils can help slow the loss of carbon to the atmosphere. CLR colleagues Prof David Coomes, Dr Ross Morrison and Prof Chris Evans are also co-authors.
Published in Global Change Biology, the study investigates how centuries of farming have changed the peat soils of the East Anglian Fens, and what that means for storing carbon today.
Lowland peatlands store vast amounts of carbon in peat soils that has built up over thousands of years. When these peat soils are drained, the buried plant material is exposed to air, causing it to break down and release carbon dioxide into the atmosphere.
The team surveyed ten sites across the Fens, where peatlands have been drained for cultivation since the seventeenth century. They found that as peat becomes thinner, it mixes with the clay and silt beneath it. Some of the carbon it then becomes attached to these mineral particles, making it harder for microbes to break down and slows the loss of carbon from the soil.
We found that some of the remaining carbon becomes attached to minerals, making it harder to break down. This won't stop carbon loss, but can help slow it down.
The findings improve our understanding of how carbon behaves as lowland peat soils are lost. Although mixing with clay and silt can slow carbon loss, it is not enough to stop it. Protecting and restoring peat soils and peatlands remains essential for reducing greenhouse gas emissions.
The study is part of our wider work to understand how soils, farming and ecosystems can work together to reduce emissions, support nature recovery and help develop nature-based solutions for climate change.