University of Exeter funding: NERC GW4+ DTP PhD studentship

Unravelling and modelling endogenous controls of plant respiration. PhD in Geography (NERC GW4+ DTP) Ref: 3686

About the award


Lead Supervisor

Dr Stephen Sitch, Department of Georgraphy, College of Life and Environmental Sciences, University of Exeter

Additional Supervisors

Dr Lina Mercado, Department of Georgraphy, College of Life and Environmental Sciences, University of Exeter

Dr Anna Harper, Department of Mathematics, College of Engineering, Mathematics and Physical Sciences, University of Exeter

Dr Douglas Clark, Centre for Ecology and Hydrology, Wallingford

Prof Dan Bruhn, Department of Biology, Aalborg University, Denmark

Location: University of Exeter, Streatham Campus, Exeter, EX4 4QJ

This project is one of a number that are in competition for funding from the NERC GW4+ Doctoral Training Partnership (GW4+ DTP).  The GW4+ DTP consists of the GW4 Alliance of research-intensive universities: the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five unique and prestigious Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology & Hydrology, the Natural History Museum and Plymouth Marine Laboratory.  The partnership aims to provide a broad training in the Earth, Environmental and Life sciences, designed to train tomorrow’s leaders in scientific research, business, technology and policy-making. For further details about the programme please see

For eligible successful applicants, the studentships comprises:

  • A stipend for 3.5 years (currently £15,009 p.a. for 2019/20) in line with UK Research and Innovation rates
  • Payment of university tuition fees;
  • A research budget of £11,000 for an international conference, lab, field and research expenses;
  • A training budget of £3,250 for specialist training courses and expenses.
  • Travel and accomodation is covered for all compulsory DTP cohort events
  • No course fees for courses run by the DTP

We are currently advertising projects for a total of 10 studentships at the University of Exeter


Students who are resident in EU countries are eligible for the full award on the same basis as UK residents.  Applicants resident outside of the EU (classed as International for tuition fee purposes) are not eligible for DTP funding. Residency rules are complex and if you have not been resident in the UK or EU for the 3 years prior to the start of the studentship, please apply and we will check eligibility upon shortlisting.

Project Background 

The reliability of current and future climate predictions depends, among other factors, on how well key processes are represented by climate models, our current tools to predict climate change. It is now well understood that the land carbon cycle has a strong influence on our climate (Booth et al 2002, Friedlingstein et al 2014). Specifically, plant respiration is an important component of the global carbon cycle, releasing CO2 back from vegetation to the atmosphere. However it is still poorly represented in these models resulting in likely overestimate of simulated global rates of respiratory fluxes, which introduces a large uncertainty in future climate prediction (Atkin et al 2015; Huntingford et al 2017).  Moreover, we know  that  plant and ecosystem respiration vary through the 24 hour daily cycle due to both variations in temperature but also due to endogenous rhythms, i.e. the circadian clock (Bruhn et al. 2008 and unpublished data sets from the supervisory team). However, current state-of-the-art models only account for the former. This project will use a combined data-modelling approach to fill this knowledge gap and thus help improve carbon cycle and future climate predictions. The main hypothesis this project will test is that we expect diurnal variation in plant respiration to be equally controlled by temperature fluctuations and circadian rhythms.

Project Aims and Methods 

The aim of the project is twofold : i) improve our understanding of endogenous controls of plant respiration over the diurnal cycle and based on this ii) develop an algorithm suitable for implementation in land surface & climate models that can properly represent both the temperature and endogenous control of plant respiration.

The method involves a combination of measurements and modelling :

  • Collection of plant respiration data in different ecosystems (temperate, tropical, tropical montane) over the diurnal cycle.
  • Data analysis to develop an algorithm that can represent endogenous and temperature influences on plant respiration. 
  • Implementation of  plant respiration algorithm into the JULES model.  
  • Application of our new algorithm to assess implications of introducing endogenous rhythms controlling plant respiration on current and future climate predictions. 

The project offers excellent opportunities for generating new understanding and high-impact publications.

There is flexibility for the candidate to decide on research direction within the topic of the project, and to be in charge of experimental design, data analysis and modelling protocol. 


An experimental site in the Colombian Andes (common garden plantation) where measurements will take place



Gas-exchange measurements using a LICOR-6400

Candidate Requirements

We look for a strongly motivated candidate with understanding of plant carbon-climate interactions. The student should be able to work in the field under hot/humid but also challenging conditions. The candidate should be numerically skilled with experience with data analysis and coding in either R, python or similar programming languages.

CASE or Collaborative Partner

The Centre of Ecology and Hydrology (CEH) is a hub for the JULES land surface model of the UK climate model. CEH scientists are closely involved with the development of many land processes within JULES. Dr Douglas Clark, the CEH supervisor, will provide expert guidance and training on best practice in code development (e.g. will provide support with the implementation of diurnal circadian controls in the plant respiration scheme within JULES), and on how to perform global simulations on high performance computing systems.


In addition to generic skills such as oral presentations, scientific writing and project management, the student will receive specific training on:

-Methods needed for plant respiration measurements and designing an experimental protocol for fieldwork (some of this might take place in Denmark hosted by external supervisor). Experimental locations include, the UK, tropical montane forest (Colombia, within an existing NERC project) and also possibly a lowland tropical forest (Manaus, Brazil).

-Python coding and data (statistical) analysis required for data collected.

-Training on land surface modelling, including how to modify code within a community development environment, and how to run the model at single sites and over regional or global domains. Some of this will take place at CEH Wallingford.

References / Background reading list 

Atkin et al 2015, New Phytologist, 206:614-636 

Booth et al 2012, Environmental Research Letters, 7:024002

Bruhn et al 2008, Plant Biology, 10:185-193

Huntingford et al 2017, Nature communications, 8:1602

Entry requirements

Applicants should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK.   Applicants with a Lower Second Class degree will be considered if they also have Master’s degree.  Applicants with a minimum of Upper Second Class degree and significant relevant non-academic experience are encouraged to apply.

All applicants would need to meet our English language requirements by the start of the  project


How to apply

In the application process you will be asked to upload several documents.  Please note our preferred format is PDF, each file named with your surname and the name of the document, eg. “Smith – CV.pdf”, “Smith – Cover Letter.pdf”, “Smith – Transcript.pdf”.

  • CV
  • Letter of application outlining your academic interests, prior research experience and reasons for wishing to undertake the project.
  • Transcript(s) giving full details of subjects studied and grades/marks obtained.  This should be an interim transcript if you are still studying.
  • If you are not a national of a majority English-speaking country you will need to submit evidence of your current proficiency in English.

Reference information
You will be asked to name 2 referees as part of the application process, however we will not expect receipt of references until after the shortlisting stage. Your referees should not be from the prospective supervisory team.

If you are shortlisted for interview, please ensure that your two academic referees email their references to the, 7 days prior to the interview dates.  Please note that we will not be contacting referees to request references, you must arrange for them to be submitted to us by the deadline.

References should be submitted by your referees to us directly in the form of a letter. Referees must email their references to us from their institutional email accounts. We cannot accept references from personal/private email accounts, unless it is a scanned document on institutional headed paper and signed by the referee.

All application documents must be submitted in English. Certified translated copies of academic qualifications must also be provided.

The closing date for applications is 1600 hours GMT Monday 6 January 2020.  Interviews will be held between 10 and 21 February 2020.  For more information about the NERC GW4+ DPT please visit

If you have any general enquiries about the application process please email  Project-specific queries should be directed to the lead supervisor.

Data Sharing
During the application process, the University may need to make certain disclosures of your personal data to third parties to be able to administer your application, carry out interviews and select candidates.  These are not limited to, but may include disclosures to:

  • the selection panel and/or management board or equivalent of the relevant programme, which is likely to include staff from one or more other HEIs;
  • administrative staff at one or more other HEIs participating in the relevant programme.

Such disclosures will always be kept to the minimum amount of personal data required for the specific purpose. Your sensitive personal data (relating to disability and race/ethnicity) will not be disclosed without your explicit consent.


Application deadline:6th January 2020
Value:£15,009 per annum for 2019-20
Duration of award:per year
Contact: PGR Enquiries