Grace Handy profile picture

Grace Handy

University of Birmingham


Impact of CO2 rise on root, leaf, and wood production: The future of tree C allocation


  • Professor Rob Mackenzie, University of Birmingham
  • Dr Adriane Esquivel-Muelbert, University of Birmingham
  • Dr Marie Arnaud, Paris Sorbonne University
  • Dr Matthew Wilkinson, Forest Research
  • Dr Deborah Hemming, Met Office
  • Professor Richard Norby, Honorary Professor, BIFoR, University of Birmingham

PhD Summary

Previous research suggests that trees can carry out increased levels of photosynthesis under elevated CO2, but growth cannot increase indefinitely due to other limiting factors such as nutrient availability. This project will focus on a tree’s ability to combat this by allocating extra carbon belowground by increasing root growth, exudation, and microbial activity to explore and obtain more nutrients and water. The research for this project will be carried out at the Birmingham Institute of Forest Research Free Air Carbon Enrichment experiment (BIFoR FACE) , in collaboration with Forest Research and the Met Office. Root production will be measured through the collection of images using a minirhizotron camera, a non-destructive root investigation technique, which will then be vectored and converted to rates of root production. This methodology will be used alongside more traditional methods of root extraction and examination using soil cores. Data on root production will then be considered alongside other relevant carbon storage data collected in the previous years of the BIFoR experiment, such as leaf area, to further understand where trees will allocate extra carbon under elevated CO2 and provide vital information to understand the future of the global carbon sink.

Previous activity

I graduated from the University of Birmingham with an MSci in Biological Sciences in the summer of 2022. My master’s thesis focussed on the environmental drivers of Eurasian otter populations across the Birmingham and West Midlands canals. Although a PhD in plant responses to elevated carbon dioxide may appear to be a change in direction, the impacts of environmental change on the natural world has always been my biggest passion, and I was an active volunteer for BIFoR (the now host institute to my PhD) throughout my undergraduate degree.

Why did you choose doctoral research?

Designing and carrying out my own novel research project in my master’s year to expand the knowledge of not only myself but the wider scientific community, has provided a level of satisfaction which I believe can only be equalled at this early stage in my career through a PhD. I have always thrived in education and feel the best and truest version of myself whilst learning, something I wasn’t quite ready to give up after completing my undergraduate degree.

Why did you choose CENTA?

Most importantly this CENTA studentship gave me the opportunity to work alongside experts in the field at BIFoR FACE, a one-of-a-kind institute of global importance in the field I am most passionate about – the future health of biodiversity under the current climate crisis. Alongside this, a doctoral researcher can be quite an isolating role but being a CENTA student offered access to a community of other PhD students in the same position both within and across universities. The DTP also provides access to range of valuable training opportunities to aid development of academic and transferable skills throughout the programme.

Future plans

I have found my niche in climate and environmental sustainability, and a PhD is the best avenue to become elite in this field. I currently see myself staying in academia but, whether I continue along this career path or move into industry, my main aspiration remains to leave a positive mark on the planet and hopefully inspire others that they can do the same.