Carbon and peat dynamics

Moorland site in South Yorkshire subjected to managed burning where black carbon is stored in peat

Our overall aim in this project is to increase our understanding of soil carbon storage and dynamics in a diverse range of soil and Quaternary environments.

This includes understanding the processes controlling the presence and fate of black (pyrogenic) and inorganic carbon in soil systems.

We conduct field-based investigations, laboratory experiments and analyses to address specific research questions.

Locating carbon inside soil aggregates

At the UK's synchrotron 'Diamond Light Source' in Harwell we're trying to find where the organic carbon is locked away inside soil aggregates. If we know this we can understand whether the structure of the soil might influence whether it is available for bacteria to feed on. If the carbon is freely available then the organic matter becomes an active source of CO2, and may change with changing climate scenarios. If the organic matter is locked deep inside the aggregates then it might not be available to bacteria. So different soil types could potentially be sources or sinks of CO2. It's all about understanding the processes within the carbon cycle.

Here are two videos explaining exactly what we got up to with our soil aggregates (aka clumps of soil held together by clay and organic matter including bacteria etc) at Diamond:

Black carbon in upland peat environments

The practice of moorland burning produces black carbon which is preserved in peat.

There is considerable interest on the impacts of burning on carbon storage in upland environments and the processes affecting the fate of black carbon.

We are studying these processes in an upland blanket peat of the Peak District, South Yorkshire.

We are also testing novel methods for the analysis of black carbon in soils and reservoir sediments.

Pedogenic carbon formation in soil

An image of needle-like (micrometer scale) pedogenic calcium carbonates formed in the clay topsoil of Nottinghamshire, England

Most research in relation to the terrestrial carbon cycle and climate change has focused on the organic carbon fraction of the soil.

Soil carbon is also present as inorganic carbon, occurring as primary(lithogenic) carbonate minerals derived from the bedrock, and secondary (pedogenic) carbonate minerals formed in situ through inorganic and biogenic soil reactions.

This inorganic carbonate may persist, as testified to by the presence of similar calcrete/rhizocrete mineralisation preserved in Quaternary palaeosoils, and may become increasingly important if climate change leads to drier conditions and greater evaporation from the soil.

In collaboration with university partners, we are studying the formation and dynamics of pedogenic carbonates in soils, particularly at the fungal hypha-soil interface.