How do species interactions determine species ranges? NERC GW4+ DTP studentship. PhD in Biosciences (Funded) Ref: 3359

About the award


Lead Supervisor: 

Dr Regan Early, Department of Biosciences, College of Life and Environmental Sciences, University of Exeter

Additional Supervisors:

Dr Bram Kuijper, Department of Biosciences, College of Life and Environmental Sciences, University of Exeter

Dr Steven White, Centre for Ecology & Hydrology, Wallingford


University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE .

This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP).  The GW4+ DTP consists of the Great Western Four alliance of the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five Research Organisation partners:  British Antarctic Survey, British Geological Survey, Centre for Ecology and Hydrology,  the Natural History Museum and Plymouth Marine Laboratory.  The partnership aims to provide a broad training in earth and environmental sciences, designed to train tomorrow’s leaders in earth and environmental science. For further details about the programme please see

For eligible successful applicants, the studentships comprises:

  • An index-linked stipend for 3.5 years (currently £14,777 p.a. for 2018/19);
  • Payment of university tuition fees;
  • A research budget of £11,000 for an international conference, lab, field and research expenses;
  • A training budget of £4,000 for specialist training courses and expenses.

Up to 30 fully-funded studentships will be available across the partnership.

Students from EU countries who do not meet the residency requirements may still be eligible for a fees-only award but no stipend.  Applicants who are classed as International for tuition fee purposes are not eligible for funding.

Project details

It is clear that environmental conditions alone cannot explain species geographic ranges. Biotic interactions (BIs) are widely suggested as alternative explanations, but it is unknown how often, in what situations, and in what ways BIs predominantly affect species ranges. Addressing this challenge is one of the most central aims of ecology, and is a major ‘missing piece’ in efforts to understand global biodiversity patterns and forecast biodiversity responses to environmental change.

This studentship will take a highly novel approach, investigating how abiotic conditions alter two key components of BI strength: frequency and intensity1,2. These two components vary across geographic space and with environmental conditions, leading to predictable, but unstudied, effects on species’ ranges1. Much research in this area is hamstrung by limited data on BI strength and species’ ranges, which are taxonomically and geographically biased and cannot infer causality 3.The studentship will therefore take a theoretical approach to develop general principles that can be tested with empirical data.

Project Aims and Methods 

a) Investigate the ecological and evolutionary parameters and environmental scenarios that permit BIs to structure species’ ranges. Use Lotka-Volterra (LV) models of two interacting species in which the strength of the interaction depends on species-specific parameters drawn from literature-informed expectations1,4, . LV models will be solved for specified birth and death parameters to identify a feasible range of interaction strengths.

b) Measure the potential magnitude of BI effects on species’ ranges. Use an Integro Difference equation (IDE) approach, in which IDEs include biotic and abiotic effects on population growth rates, drawing parameter values from a) and employing realistic dispersal capacities5. IDEs for multiple species will be simulated simultaneously in landscapes based on real topographic and vegetation maps.

c) Predict taxa and ecosystems where BI effects on species’ ranges could be stronger than environmental effects. Look for taxa with ecological traits and geographic regions with environmental gradients that correspond to parameters identified in a).

d) Test predictions from c) with empirical data. Use joint Species Distribution Models6, meta-analysis1, and existing demographic datasets(e.g. 7) to search for the predicted BI effects on species’ ranges.


• Regan Early - Joint Species Distribution Modelling, collating large datasets, advanced frequentist statistics, coding in R and Python, GIS, meta-analysis, biodiversity concepts, science presentation.

• Bram Kuijper – Analysis of species interaction models (e.g., Lotka Volterra models), evolutionary game theory, simulation models in C++, eco-evolutionary models, evolutionary concepts.

• Steven White – Analysis of population and spread models, advanced computational techniques, mathematical analysis, coding in multiple languages, population dynamics, IDE modelling

• External training - Bayesian statistics, phylogenetic analysis, IDE Modelling.

The student will attend FABio, the lead supervisor’s biweekly research group. FABio is a ‘community of practice’, where members from undergraduate to academic share literature, field and computational analytical skills, and present their research developments to each other.

The student will also attend international, inter-disciplinary, working groups, via the lead supervisor’s current commitments and long-term collaborations, in Spain and the USA. The student will learn how to integrate data from a wide range of taxa and disciplines (e.g. including agricultural ecology, disease, and palaeoecology), and learn how to jointly develop conceptual as well as empirical manuscripts.

CASE or Collaborative Partner 

Steven White has developed advanced IDE modelling techniques highly relevant to biotic interactions. White, and colleagues at CEH, excel in the application of cutting-edge models to real-world natural resource management, including the spread of disease and biological invasions. His involvement will therefore broaden the fundamental scientific expertise in the project team, and enhance the project’s impact and the student’s employability.

References / Background reading list

1. Early R & Keith S. (2019) Geographically variable biotic interactions and implications for species ranges.  Global Ecol Biogeogr, In press.
2. Louthan AM, et al. (2015) Where and When do Species Interactions Set Range Limits? Trends in Ecology & Evolution; 30(12), 780 – 792.
3. Dormann CF, et al. (2018) Biotic interactions in species distribution modelling: 10 questions to guide interpretation and avoid false conclusions. Global Ecol Biogeogr, 00:1 –13.
4. Emmerson M, et al. (2004) How does global change affect the strength of trophic interactions? Basic and Applied Ecology, 5(6): 505-514
5. Morrison, L., et al. (2018). "Species traits suggest European mammals facing the greatest climate change are also least able to colonize new locations." Diversity and Distributions 24(9): 1321-1332.
6. Pollock LJ, et al. (2014), Understanding co‐occurrence by modelling species simultaneously with a Joint Species Distribution Model (JSDM). Methods Ecol Evol, 5: 397-406. doi:10.1111/2041-210X.12180
7. Hemrová, L., et al. (2017). "Drivers of plant species’ potential to spread: the importance of demography versus seed dispersal." Oikos 126(10): 1493-1500.

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.

Candidate Requirements

The candidate should be fascinated by the ‘big questions’ in ecology, such as how biodiversity gradients are formed, and possibly by the effects of environmental change (e.g. climate change, biological invasions) on species’ ranges. Experience with some of the following is needed: advanced statistics, analytical modelling, coding, managing large datasets, meta-analysis, and/or developing conceptual frameworks for analyses.

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.
  • Two References (applicants are recommended to have a third academic referee, if the two academic referees are within the same department/school).

Reference information
You will be asked to name two referees as part of the application process.  It is your responsibility to ensure that your two referees email their references to, as we will not make requests for references directly; you must arrange for them to be submitted by 7 January 2019

References should be submitted 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 midnight on 7 January 2019.  Interviews will be held between 4 and 15 February 2019.

If you have any general enquiries about the application process please email  Project-specific queries should be directed to the 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:7th January 2019
Value:£14,777 per annum for 2018-19
Duration of award:per year
Contact: PGR Enquiries