About the Project
A fully funded NERC E4 DTP PhD studentship to investigate the influence of peatland restoration on the chemical composition of organic matter reaching aquatic systems, and implications for drinking water providers.
Understanding how land use affects aquatic dissolved organic matter (DOM) is important both for determining aquatic carbon budgets, and for drinking water providers, who are required to remove large quantities of DOM during water treatment. Peatlands are disproportionately large sources of DOM and it is well established that peatland land management, including drainage, and forestry can impact DOM delivery to freshwaters. Internationally, peatlands are being restored to re-establish ecosystem services, including C sequestration, biodiversity and flood risk management. For example, the Scottish Government’s Climate Change Plan sets targets to restore 250,000 ha of peatland by 2030. Improvements in water quality, including reductions in water colour and DOM, are an assumed benefit of peatland restoration, yet the evidence base is so far equivocal as to whether this benefit is realised (Williamson et al., 2021). Detailed evidence, including molecular composition changes of DOM before, during and after restoration, is required to understand how peatland restoration affects freshwater chemodiversity, and in turn, what impact these changes may have on in-stream biodiversity. Examining the composition of DOM is hindered by its complexity. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) is the only technique to date that is able to resolve the thousands of compounds in DOM. Studies by the Bell group and others (Herzsprung et al., 2017) using FT-ICR-MS have shown that the composition of DOM within the peat profile is impacted by drainage and restoration. The question remains if these compositional changes are reflected in the DOM exported to freshwaters. Mapping on to peatland restoration efforts in the Forth catchment, central Scotland, this PhD project will provide critical evidence in understanding the character and flux of DOM, and wider freshwater biogeochemical changes, and their implications for in-stream biota, following peatland restoration.
- Does peatland restoration influence the total DOM flux relative to control catchments?
- Is the biogeochemical signature of DOM draining from restored peatland fundamentally different from DOM draining from control catchments, and can this difference be attributed to specific organic matter sources?
- Are the same effects observed across different peatlands undergoing restoration?
- What are the implications of peatland restoration for in-stream biogeochemistry, both in terms of carbon cycling and freshwater ecology?
The study area will be in the Forth catchment, Scotland. The project will compare measurements of DOM composition using FT-ICR-MS and biological communities in streams and other freshwater habitats (ditches, small ponds) in peatlands which are restored or undergoing restoration with freshwater ecosystems in control areas. The biogeochemical measurements will be conducted monthly across two years at a number of representative sites within the control and restored landscape to assess impact of peatland restoration on quantity and composition of aquatic DOM, and seasonal and site specific variation. Monthly field campaigns will also include water sampling to determine nutrient concentrations (phosphorus and nitrogen compounds), in situ physico-chemical measurements (conductivity, pH and temperature) and recording of other relevant site information, such as depth, width and flow. The ecological assessment will be conducted seasonally in spring, summer and autumn for macroinvertebrates and once a year in summer for macrophytes, and it will follow RIVPACS (Murray-Bligh et al., 1997) and LEAFPACS2 (WFD-UKTAG, 2014) methods for assessing river and lake ecological quality, respectively.
Samples will be analysed using a suite of laboratory instruments, including a 12T FT-ICR mass spectrometer, Total Organic Carbon (TOC) and SEAL AQ2 analysers. Biological samples will be processed and analysed following the UK analysis procedures described in Murray-Bligh et al. (1997) and WFD-UKTAG (2014).
A comprehensive training programme will be provided comprising both specialist scientific training and generic transferable and professional skills. The student will be registered in the School of Chemistry and will follow the curriculum of the Chemistry Postgraduate School. Specific training relevant to the project will be provided by UKCEH, the supervisor team or an external body. This includes water sampling, ecological assessments (sampling and identification skills), advanced statistics in programming languages such as R/python and training on instrumentation, such as FT-ICR-MS.
A minimum 2.1 degree in chemistry/biochemistry, environmental science or ecology or equivalent.
Experience with techniques such as UV-VIS and statistics.
A UK driving licence for field work.
Experience collecting field data and working knowledge of R/Python is highly desirable.
For more information please see the project description on the E4 DTP website: https://www.ed.ac.uk/e4-dtp/how-to-apply/supervisor-led-projects/project?item=1448
Application Process: Please apply through the E4 DTP website: http://www.ed.ac.uk/e4-dtp/how-to-apply
Herzsprung, P., Osterloh, K., von Tümpling, W., Harir, M., Hertkorn, N., Schmitt-Kopplin, P., Meissner, R., Bernsdorf, S. and Friese, K., (2017). Differences in DOM of rewetted and natural peatlands–Results from high-field FT-ICR-MS and bulk optical parameters. Science of the total environment, 586, 770-781.
Koskinen, M., Tahvanainen, T., Sarkkola, S., Menberu, M. W., Laurén, A., Sallantaus, T., Marttila, H., Ronkanen, A-K., Parviainen, M., Tolvanen, A., Koivusalo,H., Nieminen, M. (2017). Restoration of nutrient-rich forestry-drained peatlands poses a risk for high exports of dissolved organic carbon, nitrogen, and phosphorus. Science of The Total Environment 586: 858-869.
Murray-Bligh, J. A. D., Furse, M. T., Jones, F. H., Gunn, R. J. M., Dines R. A., Wright, J. F. (1997). Procedure for collecting and analysing macroinvertebrate samples for RIVPACS. Joint publication by the Institute of Freshwater Ecology and the Environment Agency, 162 pp.
Shah, N. W., Nisbet., T. R. (2019). The effects of forest clearance for peatland restoration on water quality. Science of the Total Environment 693: 1 – 16.
WFD-UKTAG. (2014). UKTAG River Assessment Method Macrophytes and Phytobenthos, Macrophytes (River LEAFPACS2). Publication by Water Framework Directive – United Kingdom Technical Advisory Group, 27 pp.
Williamson, J., Evans, C., Spears, B., Pickard, A., Chapman, P. J., Feuchtmayr, H., Leith, F., and Monteith, D. (2020). Will UK peatland restoration reduce dissolved organic matter concentrations in upland drinking water supplies?, Hydrology and Earth System Sciences Discussions [preprint], https://doi.org/10.5194/hess-2020-450.