Project highlights

  • Biogeochemistry project with links to climate change consequences 
  • Practical project with potential for field and lab-based experiments. 
  • Impact on current GHG budgets and future emissions predictions 


Greenhouse gases (GHGs), such as methane (CH4) and nitrous oxide (N2O), contribute to the warming of the lower atmosphere and planetary surface. Atmospheric GHG concentrations have increased dramatically since the industrial revolution, causing a significant warming trend in the Earth’s climate. It is important to quantify natural and human-induced GHG emissions for the development of climate research and global GHG budgets. The aim of this project is to investigate how GHG emissions from plants are affected by stress and environmental change (Figure 1).  

An image summarising the main themes of the PhD project. Arrows from images representing environmental stressors (herbivory, UV radiation) and future environmental conditions (temperature and moisture) point towards a tree in the centre. An arrow labelled ‘GHG emissions?’ points away from the tree to represent the unknown change in GHG emissions due to the factors represented by the arrows that point towards the plant.

Figure 1: Graphical representation of the scope of the research project. 

Plants directly release GHGs under aerobic conditions (Keppler et al., 2006), as well as indirectly providing an emission pathway for GHGs produced in anoxic soils (Pangala et al., 2015). Aerobic GHG production in plants can be caused by environmental stressors such as UV radiation, temperature, water, and herbivory (Bruhn et al., 2009; Gorgolewski et al., 2022). Evidence for aerobic methanogenesis caused by environmental stressors is either from laboratory studies rather than in situ measurements, or from the foliage and branches of trees rather than stems. This project would involve novel investigations into the effect of environmental stressors on the magnitude of GHG emissions from trees.  

Under future climatic and atmospheric conditions, variations in environmental conditions are likely to alter the magnitude of GHG emissions from plants. The average global surface temperature from 2018-2100 is predicted to be higher than the 1850-1900 average by up to 1.8°C under the lowest GHG emissions scenario and up to 5.7°C under the highest emissions scenario. Variables such as temperature and moisture are known to affect GHG production and transport through trees over seasonal timescales (Pangala et al., 2015). However, the potential effects of changing environmental conditions due to predicted global warming on plant GHG emissions (from either aerobic or anaerobic GHG sources) have yet to be assessed. During this project, experiments will be developed to determine the expected changes in GHG emissions from plants under future climate and environmental scenarios. 


The Open University


  • Climate and Environmental Sustainability
  • Organisms and Ecosystems


Project investigator

Alice Fraser-McDonald, The Open University, [email protected]


Carl Boardman, The Open University, [email protected] 

How to apply


This project would involve fieldwork, including measuring CH4 and N2O emissions from tree stems and plants. These measurements would likely be conducted using a gas sampling method which uses a recirculating closed-loop system between gas flux chambers and a GHG analyser. There may also be the potential to measure larger fluxes using gas sensors affixed to a drone. These techniques can be used to measure GHG fluxes in situ. Laboratory and mesocosm experiments would be developed to investigate how GHG emissions from plants may change under altered environmental conditions. The gas sampling method would be used in a laboratory setting to measure emissions from plants growing in controlled environment units. Data would be scaled up to provide estimates of national and international significance in terms of GHG budgets and a global warming context.  

Training and skills

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.  

Training and support will be provided for planning and carrying out field and lab-based experiments. If appropriate, General Visual Line of Site (GVC) training will be arranged for the student to allow them to pilot an unmanned aircraft to collect gas emissions measurements. Students will also develop skills in statistical analysis and presentation of quantitative data using software such as R, SPSS and Origin. 

Further details

Further details on how to contact the supervisor for this project and how to apply for this project can be found here: 

For any enquiries related to this project please contact Alice Fraser-McDonald, The Open University, [email protected].

To apply to this project: 

Applications must be submitted by 23:59 GMT on Wednesday 10th January 2024. 

This project would suit someone with a strong background and interest in environmental science, or a related scientific discipline. A proven ability to conduct experimental work and carry out statistical analyses would be desirable, but not essential. The successful applicant would work in the Environment and Sustainability team in the School of Engineering and Innovation at the Open University 

Possible timeline

Year 1

Undertake a literature review and develop methods required for experimental work including chamber design, training with GHG analyser, and drone training (if appropriate). Locate appropriate field sites and plan field and lab work 

Year 2

Carry out fieldwork across a range of sites to understand the effect of environmental stressors on the magnitude of GHG emissions from trees. Conduct lab work using controlled environment units to determine the expected changes in GHG emissions from plants under future climate and environmental scenarios. Perform statistical analysis of collected data and use preliminary results to inform follow-up lab and fieldwork. 

Year 3

Final lab and fieldwork based on findings from the previous years and completion of data analysis. Write up the results of the project and submit a thesis. Possible publication of paper(s) would be strongly encouraged. 

Further reading

Bruhn, D., Mikklesen, T. N., Obro, J., Willats, W. G. T., and Ambus, P. (2009) ‘Effects of temperature, ultraviolet radiation and pectin methyl esterase on aerobic methane release from plant material’ Plant Biology, 11 (S1), pp. 43-48. DOI: 10.1111/j.1438-8677.2009.00202.x. 

Gorgolewski, A., Vantellingen, J., Caspersen, J. P., and Thomas, S. C. (2022) ‘Overlooked sources of methane emissions from trees: Branches and wounds’, Canadian Journal of Forest Research, 52 (8), pp. DOI: 10.1139/cjfr-2021-028. 

Keppler, F., Hamilton, J. T. G., Braß, M., and Röckmann, T. (2006) ‘Methane emissions from terrestrial plants under aerobic conditions’, Nature, 439(12), pp. 187-191. DOI: 10.1038/nature04420. 

Pangala, S. R., Hornibrook, E. R. C., Gowing, D. J., and Gauci, V. (2015) ‘The contribution of trees to ecosystem methane emissions in a temperate forested wetland’, Global Change Biology, 21, pp. 2642 – 2654. DOI: 10.1111/gcb.12891.