The role of natural and artificial pools in northern peatland carbon cycling

Lead Research Organisation: NERC CEH (Up to 30.11.2019)
Department Name: Billett

Abstract

Since the end of the last ice age large amounts of atmospheric carbon dioxide have been slowly locked up in peat soils in the cool, wet, northern regions of the world as partially decomposed plant remains. If this huge reservoir of carbon was to be released back in to the atmosphere it would cause a significant rise in carbon dioxide and release methane and result in further global warming. At the moment scientists are trying to unravel the mechanisms that control the losses and gains of carbon from this large area of the Earth's surface.

Peatlands often have natural pools of water within them. However, we know little about what role these pools play in the peatland carbon cycle. Furthermore, many new pools are being created in peatlands by humans as they try to restore degraded peatlands. This is because many degraded peatlands have previously been drained using ditches. These ditches are now being blocked up with small dams thereby creating tens of thousands of new pools along the length of the blocked ditches.

Our project seeks to examine the role of natural and artificial pools in the peatland carbon cycle. It will measure flows of water and carbon into and out of pools in order to understand whether the pools play an important role in processing the carbon.

Additionally it is known that many peatlands contain connected cavities within them known as soil pipes. These are not artificial pipes, but just natural connected holes within the peat. Some peatland pools which are connected to pipes may therefore be connected to large carbon sources from some distance away, but no-one has ever studied this before.

In summary, this project will investigate the role of pools in carbon cycling within northern peatlands. It will seek to understand processes operating in and around pools and the role of natural pipes in mediating these processes. It will focus on two pool types: natural pools and pools that have been created through peatland restoration by damming of drainage ditches. For both pool types we will examine those that are connected to pipes and those that are unconnected to pipes.

This work is fundamental to our understanding of the role of peatlands in the global carbon cycle. Without this research we will be unable to properly predict carbon fluxes from peatlands under climate change scenarios because we will not understand what drives carbon cycling in peatland pools. The work is urgent: without it we will be unable to explain how the large number of pools currently being created by practitioners via drain blocking is affecting carbon cycling within, and carbon release from, peatlands. The results from this project are also vital to informing the future management and restoration of peatlands in order to optimise their potential to mitigate global warming.

Planned Impact

Blanket peat covers 15 % of the UK. Millions of ponds are spent every year on restoring and conserving UK peatlands. Drain blocking is actively being pursued as a management strategy and this is creating thousands of new pools in peatlands. Our project will be crucial for peatland managers to understand the role of peatland pools in carbon turnover and release in peatlands. It will enable them to understand the dynamics of both natural and artificial pools and this can be factored in to management decisions around ecosystem services and carbon accounting. Carbon accounting in peatlands is very important to many organisations and this has been demonstrated most recently by the IUCN UK peatlands programme. Efforts are currently being made to include peatlands in the UK's greenhouse gas inventory and numerous organisations and businesses (e.g. water companies, restoration organisations etc) have a vested interest in improved science knowledge in this area. Our project will therefore be of direct use for organisations such as Scottish Natural Heritage, Defra, Natural England, the Environment Agency, Countryside Council for Wales, JNCC and Scottish Environment Protection Agency (SEPA) who will be able to use outputs informing and formulating policy on preservation and remediation of peatland environments. Other interested parties include local authorities, private and public land owners and charities such as the Royal Society for the Protection of Birds, National Park Authorities and the Forestry Commission, peatland conservation bodies (e.g. Moors for the Future, Peatscapes), hunting estates, farmers and user groups such as the Ramblers Association, Moorland Association, The National Trust and wildlife trusts. Fliers, information sheets, policy briefs, websites (including on-line films) and workshops will be developed during the project to maximise the impact of the work.