Peatlands represent one of the largest stores of terrestrial carbon, accounting for ~21% of the global total soil carbon stock. Increasing food and energy needs have led to drainage of peatlands for cropping and forestry that cause huge losses of carbon. Climate warming, increased drought occurrences and fires in these fragile ecosystems exacerbate uncertainty over the fate of peatland carbon. Increased effort is therefore required to develop sustainable management approaches for peatlands, which is expected to make an important contribution to climate change mitigation in Scotland.
Drainage and climate stressors such as drought and warming impact the hydrology of wetlands such that the removal of water-logged anoxic conditions leads to increased decomposition of the otherwise preserved peat organic matter and release of CO2 back to the atmosphere (Kitson & Bell, 2020; Tiemeyer et al., 2016). Such conditions may reduce methane emissions but increased CO2 release outweighs the climate benefits of methane reduction in terms of long-term global warming potential (Huang et al., 2021). Fires, on the other hand, primarily affect belowground carbon cycling through change in aboveground organic matter and therefore decomposition rates and CO2 flux.
Microbes (bacteria, archaea, viruses, fungi and other microeukaryotes) act as gatekeepers of soil-atmosphere carbon exchange because their growth, activity and interactions with the environment control the fate of carbon inputs (Malik et al., 2018). However, there is a lack of mechanistic understanding of the microbial physiological processes in peatlands that are responsible for carbon cycling, and their sensitivity to multiple climate stressors such as warming, drought and fire (Ritson et al., 2021).
The project aims to investigate microbial carbon cycling processes in intact and degraded peatlands that are under the influence of climate extremes, which are becoming increasingly frequent. There is a general consensus that degraded peatlands are less resilient to climate extremes such as severe droughts, heatwaves and fires in comparison to intact peatlands (Page & Baird, 2016). This PhD project will rigorously test the response of microbial functions and carbon sequestration rates to climate extremes. Such assessments will be performed in intact and degraded (or recently restored) peatlands at multiple sites in Scotland (Flow Country and Cairngorms). Access to experimental sites subject to climate extremes will be available. In addition, we will perform mesocosm experiments simulating multiple climate stressors, individually and in combinations, in intact and degraded peatlands to study the resilience of microbial processes and carbon cycle feedbacks.
Microbial physiological processes will be examined using a trait-based framework employing a combination of metabolic assays, shotgun metagenomic assessments and gas flux measurements. Such a combination of genotypic and phenotypic measurements will enable the project to link genomic traits to carbon sequestration rates under different treatment combinations. Taken together, this knowledge will provide the basis for better prediction and management of microbial processes in peatlands to enhance carbon storage under future climate.
It may be possible to undertake this project part-time, in discussion with the lead supervisor, however, please note that part-time study is unavailable to students who require a Student Visa to study within the UK.
Informal enquiries would be welcomed for a discussion. Please contact Dr Ashish Malik ([Email Address Removed]) for more information.
Academic Eligibility:
Applicants to the SUPER DTP are expected to have a minimum of a 2:1 UK honours degree (or equivalent). Applicants with a 2:2 at honours level will be considered on the condition they have a distinction at Masters level (or equivalent).
Application Procedure:
- Please visit this page for full instructions on how to submit your application
- Please DO NOT apply through the University application portal
Application enquiries should be made to [Email Address Removed] . Please ensure you enter SUPER DTP in the subject box.