Climate change, carbon fertilisation and tree rings (OSBORNU16SF)
Interactions between carbon dioxide (CO2), climate change and vegetation need to be understood to better predict future changes in the Earth system and climate. Climate models simulate increased water use efficiency under elevated CO2 (a “CO2 fertilisation” effect) but the size of this effect is very uncertain because feedbacks between climate and forests are poorly understood.
This is a pressing and societally-important scientific issue.
This PhD project takes a novel approach, building on recent developments made by the Climatic Research Unit and Tyndall Centre (both at UEA’s School of Environmental Sciences) in the analysis and climatic interpretation of tree-ring data in relation to the changing carbon cycle, linked with climate–vegetation modelling at the Met Office. The outcome will be improved estimates of the changing responses of tree growth to climate variations and elevated CO2.
• Computer-based analysis of existing tree-ring and climate datasets to estimate growth responses to elevated CO2 from tree-rings, accounting for biases in early temperature measurements, modern sample bias in tree-ring datasets, and new estimates of the confounding influences of tree age/size. Fieldwork to obtain additional tree-ring data may be undertaken.
• Quantify the effect of increasing CO2 concentrations on tree-ring data from multiple sites across the world, identifying systematic differences between water-stressed and temperature-limited sites to determine the importance of increased water use efficiency in promoting tree growth.
• Assess the relevance of tree-ring-based results for studying overall ecosystem productivity by comparison with observations from long-term Free-Air CO2 Enrichment (FACE) experiments.
• Evaluate the consistency of computer model simulations of forest productivity and measured tree-ring data.
You will gain transferable skills necessary to pursue a range of academic and non-academic careers: the ability to use and interpret computer models (via a 10-week placement at the Met Office in Exeter), statistical analysis of data, critical evaluation of scientific results, advanced computer programming in (e.g.) ‘R’, and communication at technical and scientific levels.
At least a 2:1 honours degree in a relevant subject area (Environmental Sciences, Biology, Physics, Chemistry, Maths, Geography or a related discipline), an aptitude for research, numerate and a clear communicator.
This PhD project is offered on a self-funding basis. It is open to applicants with funding or those applying to funding sources. Details of tuition fees can be found at http://www.uea.ac.uk/pgresearch/pgrfees.
A bench fee is also payable on top of the tuition fee to cover specialist equipment or laboratory costs required for the research. The amount charged annually will vary considerably depending on the nature of the project and applicants should contact the primary supervisor for further information about the fee associated with the project.