Geography: Fully Funded Royal Society and Swansea University PhD Scholarship: Climate-related tree health and their role in the carbon balance

Climate-related tree health and their role in the carbon balance: Understanding the effects of climate and associated vegetation condition and stress on carbon fluxes across a western European latitudinal gradient

This scholarship is funded by the Royal Society and Swansea University’s College of Science.

Start date: January 2020

Project supervisors:

Supervisor 1: Dr Jacqueline Rosette, Department of Geography
Supervisor 2: Dr Sietse Los, Department of Geography
External supervisor: Dr Juan Suárez, Forest Research, Northern Research Station

Project description:

Carbon models deviate considerably in their predictions of the response of vegetation to future climate change, some anticipating a greater uptake of carbon whilst others forecasting a reduction in land carbon storage as a result of greater vegetation stress.

It is such fundamental discrepancies which suggest apparent legitimacy of viewpoints which challenge the existence of climate change.

Across Europe, exceptional temperatures and lack of rainfall were experienced in summer 2018, with anecdotal evidence of the early onset of senescence in continental Europe resulting from vegetation stress.

During such conditions, vegetation may reach its biological limit before the end of the growth season, potentially becoming a carbon source. The effects of this are most critical for temperate broadleaf forests since, once leaves are lost, many species are unlikely to flush again until the following season, even if environmental conditions were to improve. The conditions required to trigger such effects will be investigated within this project.

The aim of this PhD project is to improve understanding of the effects of climate-related tree condition/health and their role in the carbon balance. This will be carried out along a western European latitudinal gradient.

The research student will combine remote sensing and field/ flux tower-based observations with modelling, to inform knowledge on conditions which breach the carbon source/sink tipping point. Time series of forest parameters and condition indices will be estimated using satellite sensors with suitable temporal resolution and spectral bands to permit observations of annual phenology.

These will be coupled with climate observations (e.g. precipitation and temperature) to investigate lead/lag trends in vegetation response to climatic conditions.

Data will be further interrogated to determine conditions under which a carbon source/sink transition may occur, observed changes in phenology, and possible latitudinal movement of drought stress and consequent protective response from vegetation.

There will be the opportunity to incorporate carbon models to investigate their use and sensitivity to this information e.g. the Sheffield Dynamic Vegetation Model. The model will not only incorporate vegetation data, but also critically, soil moisture and temperature variables from satellite observations with flux tower data.

Eligibility
Candidates must have a first, upper second class honour or a Master’s degree with Merit, in a relevant discipline.

For candidates whose first language is not English, we require IELTS 6.5 (with 6.0 in each component) or equivalent. Please visit our website for a list of acceptable English language tests. We prefer candidates to have already met the English Language requirements at the point of application, although this is not a requirement.

The scholarship covers the full cost of tuition fees and an annual stipend for UK/EU candidates. Successful international candidates are expected to cover the difference in tuition fees.