CR2026_58
Title: Beneath the canopy: multiscale drivers of woodland ground beetle populations in a changing world
Lead supervisor: Chris Foster, School of Biological Sciences, University of Reading
Email: c.w.foster@reading.ac.uk
Co-supervisor: Caitlin Lewis, Forest Research; Sofia Gripenberg, School of Biological Sciences, University of Reading; Chris Andrews, UK Centre for Ecology and Hydrology
UKRI funding only covers Home fees which increase annually. International students may still apply to this project, but will be required to meet the difference between the International and Home student fees themselves.
Despite widespread concern around steep declines in insect populations, a recent analysis for several groups of insects reported an absence of overall occupancy trends for southern regions of the UK (Bourhis et al. 2025). However, assessing population change through occupancy modelling potentially overlooks declines in abundance of common species which are still present throughout their former range. Such declines are reported in several insect groups, especially for large-bodied species, e.g. moths (Fox et al., 2021) and ground beetles (Brooks et al., 2012). Unpicking the relationship between changes in occupancy and abundance is challenging due to a lack of standardised long-term monitoring of insects, but urgently needed alongside an understanding of how local changes in e.g. forest management interact with both climate and habitat change at the landscape level.
The Environmental Change Network (ECN) includes 11 terrestrial sites where biodiversity metrics have been monitored consistently since 1992/3, alongside co-located air pollution and climate measurements. Carabid beetles are a core measurement within the network, and have been monitored at most sites continuously using pitfall traps, in habitats ranging from woodland to grassland. Previous analyses of the beetle data for 1994-2008 suggested species diversity was declining in most habitats, with the exception of woodland, where species diversity was stable (Brooks et al., 2012). However, anecdotal reports suggest declines in woodland carabids at some sites within the network since the last analysis. An updated trend analysis is overdue and the consistency of the dataset provides a unique resource alongside ad-hoc biological records to understand drivers of species abundance and diversity at multiple scales.
The student will combine existing long-term data and the results of their own experiments to develop a trait-based model to predict species responses under woodland management scenarios. Throughout the project, the candidate will benefit from links to practitioners and policy-makers to develop research answering applied questions and inform the development of best-practice guidance.
This project aims to address multi-scale drivers of population change in woodland carabids through the following objectives:
Objective 1: Conduct an updated trend analysis of beetle diversity and abundance in sites within the ECN.
This could inform modelling of woodland carabid population trends at the national level, using data from the national Ground Beetle Recording Scheme and environmental data such as the UKCEH land cover change map.
Objective 2: Design natural experiments to assess the impact of site level woodland management on beetle populations
2a) In recent decades, woodland management objectives have shifted from a commercial focus to delivering multiple benefits from timber to biodiversity. However, active management in broadleaf woodland declined over the last 50 years (Amar et al., 2010) and indicators of light availability suggest woodland floors are receiving less light due to canopy closure (Smart et al 2024), a factor associated with carabid beetle diversity (Fuller et al. 2008). ECN data has been collected over 30 years at Alice Holt Forest in an unmanaged stand of oak woodland, but the wider woodland is more speciose with stands planted and managed under different forestry strategies.
2b) The ECN site in the Cairngorms features a different woodland type incorporating a succession of mature Caledonian pine forest to young, naturally colonised woodland. The student will have freedom to work with local practitioners to design investigations at this site aligned with their interests.
Work at both sites will be designed to inform how representative long-term ECN carabid data are for wider woodlands.
Objective 3: Deploy and develop alternative/novel techniques for carabid beetle sampling.
Methods typically used in the long-term monitoring of carabid beetles are biased towards larger-bodied, active species (Knapp et al., 2020). This project will calibrate traditional pitfall traps with other designs and methods, ranging from traditional approaches such as hand searching or funnel traps to developing novel or less frequently deployed techniques such as tunnel traps and subterranean pitfalls.
Training opportunities:
This project offers a 3-month placement with Forest Research at Alice Holt Forest in Surrey, with training opportunities in woodland invertebrate survey, soil sampling, vegetation and deadwood surveys, working alongside the entomology and monitoring teams. The student will have the opportunity to learn about designing and implementing management plans for UK forestry, balancing the multiple benefits from and stake-holder interests in woodlands.
Student profile:
The project would suit a student with a degree in biological sciences, ecology, zoology or a closely related environmental subject. Experience of data analysis and modelling in R Studio and of at least one GIS package (e.g. QGIS, ArcGIS, R) would be helpful but are not essential. The project would be most suitable for students eager to conduct fieldwork with an interest in advancing ecological knowledge and informing woodland management plans. UKRI funding only covers Home fees which increase annually. International students may still apply to this project, but will be required to meet the difference between the International and Home student fees themselves.
Co-Sponsorship details:
This project will receive a CASE award from Forest Research.
Reference
- Key references: Bourhis et al. 2025 https://doi.org/10.1038/s41467-025-63093-y
- Brooks et al. 2012 https://doi.org/10.1111/j.1365-2664.2012.02194.x
- Fuller, Oliver & Leather 2008 https://doi.org/10.1111/j.1752-4598.2008.00032.x