PhD Studentship: Swamped: Is Crassula helmsii a significant threat to wetland biodiversity

Swamped: Is Crassula helmsii a significant threat to wetland biodiversity?

DoS: Professor David Bilton (d.bilton@plymouth.ac.uk)

2^nd Supervisor: Dr Rob Puschendorf

3^rd Supervisor: Dr Pete Cotton

Applications are invited for a 3.5 years PhD studentship. The studentship will start on 01 October 2026

Project Description

Scientific background

Biological invasions represent one of the most significant threats to biodiversity. Freshwaters are disproportionately affected by such invasions, and home to a disproportionately large proportion of biodiversity, especially invertebrates.  They also provide crucial ecosystem services. Crassula helmsii, a native Australasian plant, has been aggressively invading European freshwaters for over 30 years, with drastic consequences for their floristic diversity. Understanding of Crassula’s impacts on invertebrates, which make up the bulk of freshwater diversity, are more limited. Our work suggests that whilst Crassula invasion changes community composition and function, it does not lead to drastic declines in fully aquatic macroinvertebrate diversity or biomass. Much of the biodiversity in sites invaded by Crassula is not fully aquatic, however, with many specialist wetland invertebrates living in the seasonally flooded margins, which are heavily invaded, alongside open water habitats. The impact of Crassula on this critical component of wetland ecosystems remains unknown, and there is an urgent need for quantitative data to inform management and policy.

Research methodology

This project will examine the effects of Crassula on wetland invertebrates using both fieldwork and laboratory experiments. Fieldwork will be conducted in established locations, where investigations of aquatic communities has already been undertaken, allowing a holistic picture of Crassula’s ecological impacts.

Training

Training in a range of skills, from freshwater invertebrate biology through experimental design, to advanced univariate and multivariate analyses of ecological data. Will gain experience of fieldwork alongside experienced scientists, develop knowledge of cutting-edge approaches in biostatistics and test fundamental ecological hypotheses about the mechanistic bases for the spread/control of invasives. Will have the opportunity to act as a university demonstrator, disseminate their work and its results via written and oral outputs, and build a library of skills and competences that will elevate their employability to a level commensurate with doctoral status, applicable across a wide range of employment.

Person specification

You must be keen to conduct fieldwork, be numerate and literate and ideally with a driving licence valid for UK use; some demonstrable experience in invertebrate taxonomy and identification is desirable although not essential, as is a training in the fundamentals of biostatistics.

Eligibility

Applicants should have a first or upper second class honours degree in Biological or Environmental Science or a relevant Masters qualification.

If your first language is not English, you will need to meet the minimum English requirements for the programme, IELTS Academic score of 6.5 (with no less than 5.5 in each component test area) or equivalent.

Successful candidates who meet UKRI’s eligibility criteria will be awarded a fully-funded ARIES studentship of fees, maintenance stipend, £20,780 p.a. for 2025/26 (2026/27 rate TBC) and research costs.

If you wish to discuss this project further informally, please contact Professor David Bilton, d.bilton@plymouth.ac.uk

Please see here for a list of supporting documents to upload with your application.

Please click on the Apply button above for further information and to apply.

The closing date for applications on 7^th January 2026. Shortlisted candidates will be invited for interview after the deadline.

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