My name is Coleen Murty and I began my PhD with Newcastle University and the British Geological Survey in September 2017. My research aims to increase current understanding of carbon cycling in peatlands and determine whether these large terrestrial carbon sinks can be preserved, protected and even harnessed to store external carbon. In this blog post, I talk about the experience I had while out on a recent field visit to my study site in Cumbria.

Coleen Murty – 1st Year Geosciences PhD Student at Newcastle University

In late February 2018, I was joined by Dr Christopher Vane (British Geological Survey) and Dr Geoff Abbott (Newcastle University) on a field visit to Butterburn Flow, the largest of 58 wetlands which 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. We were particularly lucky, as the weather was perfect with clear skies and sunshine, which is a rare occurrence on Butterburn Flow! During our 3 day visit, we took water table measurements and collected peat cores, water samples and moss samples.

Butterburn Flow, a valuable carbon sink and the largest of 58 wetlands which straddle the border between Cumbria and Northumberland.

Peat coring, water sampling and moss sampling

One of the main challenges of the trip was carrying gear and equipment through uneven and boggy ground containing loads of hidden ditches! – Although this provided me with a great opportunity to learn the technicalities of collecting different types of peat cores. We collected a series of 1-2 m peat cores using a combination of Russian coring equipment and polycarbonate tubes. Various cores were taken from 4 different sites across the bog, each containing a water level datalogger used to monitor changes in the water table overtime. 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 peatlands 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.

Two ‘push’ peat cores collected in polycarbonate tubing. Peat height ~1 metre.

A variety of water samples were collected from: the water level wells, the river which runs across the northern section of the site, and Sphagnum-dominated bog pools. Different Sphagnum moss species were also collected for species identification and chemical characterization. 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. 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. Characterizing the water extractable, solvent-extractable and macromolecular chemistry of Sphagnum moss will improve current knowledge regarding its role in carbon cycling within peatland ecosystems.

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.

Bog pool with an abundance of Sphagnum cuspidatum growing at the water surface

Levelogger well containing water monitoring equipment which records alterations in the water table (four of which are deployed across the site)

At the start of  February, undergraduate Earth Sciences and Environmental Sciences students threw on their woolly hats and high vis vests and travelled to the Lake District to assess the treatment of metal contaminated water, drained from the area surrounding the disused mine at Force Crag.

Students on route to the Force Crag field site

Disused mine at Force Crag, Lake District

The mine site has an active bioremediation scheme for metal contamination. Water drained from the mine site, which is high in zinc enters two artificial vertical flow ponds, containing sulphur reducing bacteria which immobilize zinc from the water through bacterial sulphate reduction. Students were asked to test the pH, Eh, conductivity and alkalinity of water entering the bioremediation scheme and water leaving the bioremediation scheme.

Students testing the alkalinity of water entering the bioremediation scheme

Students armed with water testing kits downstream of the two artificial vertical flow ponds

Students also got the opportunity to test the zinc content of water entering and leaving the bioremediation scheme using zinc testing field kits. The zinc content of water was inferred based on the colour produced by mixing a 20ml water sample with two chemical reagents.  When mixed with the two  reagents, water which has a high concentration of zinc produces a purple-blue solution. Whereas, water which has a low concentration of zinc produces a red-orange solution.

Water samples analysed in the field using zinc testing kits. On the left is a sample collected from water entering the bioremediation scheme which has a high zinc content and on the right is a sample collected from water leaving the bioremediation scheme which has a low zinc content

Once back at Newcastle University, students will use the data collected during this field trip in a computer practical class, where the statistical software package Minitab will be used along with ANOVA to analyse the data.

This field trip is just once example of the range of field trips undertaken by undergraduate Earth Sciences and Environmental Sciences students studying at Newcastle University.

Stay tuned to the Geosciences Group blog for updates on future fieldwork conducted by Newcastle University Geosciences undergraduate and postgraduate students.