New research into carbon capture and sequestration in peat

Butterburn Flow

Peatlands are complex systems where carbon accumulation rates exceed decomposition rates, however, this balance of carbon uptake and loss may be shifted by periods of intense drought, which are becoming more common in the light of climate change. Finding solutions to protect and preserve carbon stocks locked up in peat is essential as we move towards a more sustainable future.


Coleen sampling the peat at Butterburn Flow

In late February 2018, PhD student Coleen Murty was joined by the BGS's Chris Vane and Geoff Abbott from Newcastle University on a field visit to Butterburn Flow, the largest of 58 wetlands that lie on the border between Cumbria and Northumberland. Butterburn is a Site of Special Scientific Interest (SSSI) and is considered one of the most valuable mires in England, operating as a substantial carbon sink. During the three-day visit, they took water table measurements and collected peat cores, water samples and moss samples.

Peat coring and water sampling

Levelogger well containing water monitoring equipment

The team collected a series of 1–2 m peat cores using a combination of Russian coring equipment and polycarbonate tubes. Various cores were taken from four different sites across the bog, each containing a water-level datalogger used to monitor changes in the water table over time.

Water data and air pressure can be downloaded onto an Android device and correlated with peat cores taken nearby. Changes in the water table can have positive or negative impacts on a peatland's ability to accumulate carbon and therefore must be carefully monitored. The collected peat cores will be used for a combination of geomolecular and bulk geochemical analyses: from bulk density measurements used to estimate carbon stocks, to a series of laboratory mesocosm experiments by which peat cores will be placed in a 'microenvironment' where natural field conditions will be mimicked in order to monitor the changing chemistry of the cores in different conditions and assess their ability to sequester carbon.

Moss sampling

Bog pool with an abundance of Sphagnum cuspidatum

Sphagnum moss is the dominant peat-forming species across the Northern peatlands. It thrives in wet, acidic conditions and its high recalcitrance allows it to store large amounts of carbon compared to other peatland plants. Characterising the water-extractable, solvent-extractable and macromolecular chemistry of sphagnum moss will improve current knowledge regarding its role in carbon cycling within peatland ecosystems.

A variety of water samples were collected from the water level wells; the river that runs across the northern section of the site, and sphagnum moss-dominated bog pools. Different sphagnum moss species were also collected for species identification and chemical characterisation. The nature and abundance of carbon within the bog and river water running off the peatland will give insights into the source, stability and fate of different organic molecules being flushed through the peat profile and how their mobility affects the resilience and vulnerability of the carbon being retained within the wetland.

Contact

Contact Chris Vane for more information.