PhD Studentship: Unravelling the Sound Underground: Detecting and Estimating Earthworm Abundance Using Low-Frequency Vibrations

Background

Earthworms are synonymous with our notion of beneficial soil biology playing a key role in maintaining a healthy functional soil. Earthworm populations are estimated to have declined by a third over the past 25 years, which is inferred from sparse soil data and the widespread decline of their avian predators. 

Recent developments in soil geophones and contact microphones have enabled the recording of substrate-borne vibrations produced by earthworms (and other invertebrates) in situ. To fully exploit this emerging technology there is a need to unravel the meaning within the data. As such, this interdisciplinary project will couple mathematical models of earthworm movement, stochastic models of the measurement process and designed experiments to improve earthworm detection.  

Project

This project will work at the interface between stochastic modelling, signal processing and data science. Ultimately, the project will develop key indices that can be used to assess the health of the soil ecosystem. Such indices will be grounded in rigorous mathematics coupled with a sound understanding of the underlying earthworm ecology. Bayesian inference methodologies will be developed to estimate where and when behavioural changes occur in earthworm signals.

As part of the project, soil vibration data will be collected from the Long-Term Experiment ‘Park Grass’ at Rothamsted Research. This is the only experiment in the world where it is possible to compare and contrast signal phenomena within a field where local extinctions of earthworms have occurred (in known plots) due to management practices. Started in 1846, the plots have significantly different floral diversity and earthworm populations as a result of different long-term application of inorganic fertilisers and organic manure treatments. 

Supervisors

Dr Kirsty Hassall, Statistics

Dr Jacqueline Stroud, Warwick Crop Centre

Dr Richard Everitt, Statistics

Interdisciplinary Research

Warwick Statistics is one of the largest Statistics departments in the world, with a thriving PhD programme and a long-established reputation for research activity of the highest quality, enhancing both the PhD student experience and the demand for our PhD graduates. This interdisciplinary project will enable you to further your mathematical understanding with real-world applications and real-world impact.

The successful applicant will split their time between the Department of Statistics and Warwick Crop Centre in a roughly 75:25 split. Although the student will predominantly focus on the data science, statistical and mathematical modelling aspects, it is expected that they will co-design appropriate experiments and support data collection activities. The student will be fully supported in this interdisciplinary environment with excellent access to training for a diverse range of activities and a flexible fund to address training needs as and when they occur.

Informal Enquiries can be directed to Dr Kirsty Hassall (Kirsty.Hassall@warwick.ac.uk)

Application deadline: 10^th June 2025

Please specify the project title in your personal statement. Funding is via the EPSRC DLA Interdisciplinary Scholarship.

Start Date: October 2025

3.5-year full-time scholarship to start in October 2025, including a UKRI rate stipend, full payment of academic fees at the home rate and a Researcher Training Support Grant of up to £5,000. This funding is restricted to home fees candidates due to Council requirements.

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