The Organic Geochemistry of Peat in Transition

How to apply to the University of Bristol:

Please only email if you have an enquiry to apply please use the following link and use Geology (PhD) as the programme.

http://www.bristol.ac.uk/study/postgraduate/apply/

Closing date Friday 3 March 2023 at 23.59 GMT but the posts will remain open until filled. The preferred start date will be Oct 2023 but the funding of the project allows flexibility

Funding is available for 3.5 years at standard UKRI rates.

CERES Project Background

Microbial processes in terrestrial settings are critical to governing greenhouse gas emissions. The modern

carbon soil reservoir exceeds that of terrestrial vegetation and the atmosphere combined, and soil

microorganisms annually cycle 1/3 of the carbon photosynthesised and account for the largest natural

methane flux to the atmosphere. In doing so, they govern the chemical and climatic state of our planet. And

yet these processes remain poorly understood as they are mediated by a range of environmental factors.

Insight can be derived from geological archives that document the responses of biogeochemical systems to

past environmental perturbations across a range of timescales from 1000s to millions of years. Our previous

studies on peat and lignites provide tantalising insights into climate-driven disruption of the carbon cycle,

but the underlying mechanisms remain unresolved. This PhD, as part of the wider CERES project, will address

that by exploring the organic geochemistry of peatlands that have undergone radical transformation – from

drying and degradation to restoration to flooding.

Project Aims and Methods:

Peat and lignite deposits have long been used to explore past changes in climate, especially changes in

temperature and precipitation. However, peat deposits can also document the biogeochemical responses to

those environmental changes. To explore these, a wide range of approaches have been developed based on

changes in the bulk composition of peat, transformations in specific environmentally sensitive biomolecules

and tracers for specific microbial communities. However, they have been developed and applied to a

relatively narrow range of relatively unaltered temperate and subarctic peatlands. This project will focus on

a range of peatlands that have experienced dramatic transformations, including drainage, drying and

restoration and from a range of climate regimes from the Arctic to the Tropics.

We will explore and compare environmental and biogeochemical disruptions in Welsh, English, Swedish,

Panamanian and Colombian peatlands (and potentially peatlands from Uganda, the DRC and Papua New

Guinea). The specific sites and time intervals will be developed in collaboration with the PhD student and the

supervisory team, but we are particularly interested in documenting sites that have experienced drying,

drainage and restoration, allowing us to explore the biomolecular signature of disruption as well as its

persistence. We will determine how these disruptions affected rates of carbon accumulation and the overall

chemical composition of the peat, as well as the associated microbial communities that are involved with its

stepwise degradation to simpler substrates and eventually CO2 and methane. Working with the wider CERES

team, the PhD student will apply new lipidomic techniques, especially those arising from the distribution of

unusual archaeal and bacterial membrane lipids, to ascertain the relationships between past changes in

peatland hydrology, microbial metabolism, and carbon cycling.

Candidate requirements

The Organic Geochemistry Unit (OGU) has a long history of interdisciplinary research; as such, we are looking

for intellectually diverse applicants, welcoming your new perspectives into our lab and our obligation to train

you in the methods you will use. Similarly, we welcome and encourage student applications from minoritized

and marginalised and value a diverse research environment.

Project partners

This project builds on a long-standing Bristol-Exeter collaboration in which we have developed and applied

new approaches to understanding peatland processes. We also have collaborations in Wales, Colombia, and

Panama, ensuring access to samples and sites

Training

As part of CERES, there will be outstanding opportunitiesfor field work and associated training. We recognise

the constraints field work imposes on applicants from some backgrounds, however, and field work is not

mandatory (with samples provided by partners). The PhD focuses on geochemical investigation of peat,

including characterisation of organic matter, quantification of biomarkers and cutting-edge stable isotope

methods. As the Bristol node of the NERC Natural Environment Isotope Facility (NEIF) specialised in organic

isotope analyses, the OGU has a long track record of providing such training to diverse students from all

backgrounds. Similarly, the Earth Sciences Biogeochemistry and Geomicrobiology labs have fantastic facilities

and opportunities for training and career development. Successful applicants will also be able to access the

extensive transferable skill training associated with the NERC GW4+ Doctoral Training Partnership, as well as

those of Bristol’s Doctoral College.

Useful links

To apply: http://www.bristol.ac.uk/earthsciences/courses/postgraduate/

For information on the OGU: http://www.bristol.ac.uk/chemistry/research/ogu/

For information on CERES: https://richpancost.blogs.bristol.ac.uk/2022/09/11/ceres-climate-energy-and-carbon-inancient-earth-systems/

How to apply to the University of Bristol:

http://www.bristol.ac.uk/study/postgraduate/apply/

Closing date Friday 3 March 2023 at 23.59 GMT but the posts will remain open until filled. The preferred start date will be Oct 2023 but the funding of the project allows flexibility. Funding is available for 3.5 years at standard UKRI rates.