CR2025_61 Quantifying trends in global wetland-associated biodiversity loss

Lead Supervisor: Clare Duncan, Institute of Zoology

Email: clare.duncan@ioz.ac.uk

Co-supervisors: Manuela Gonzalez-Suarez, Department of Ecology and Evolutionary Biology, University of Reading; Rikki Gumbs, Institute of Zoology; Louise McRae, Institute of Zoology

The world’s wetlands are of critical importance to human health and well-being, providing key ecosystem services including protecting coastal areas from storms, food and fuel provision, improving water quality and recharging groundwater aquifers (Zedler & Kercher 2005). Covering ~3% of the planet’s surface, fresh and brackishwater wetlands also provide habitat for ~40% of the world’s biodiversity (Convention on Wetlands 2021). Wetlands remain among our most threatened ecosystems globally, with ~65-70% having disappeared since 1900 under increasing pressures from land-use change, water extraction, exploitation, pollution, climate change and invasive species (Davidson 2014). As a result, wetland-associated biodiversity is disproportionately at risk: the recent Living Planet Index (LPI) report reveals that monitored populations have declined by 85% since 1970, and an estimated 25% of wetland flora and fauna species are now threatened with extinction (Convention on Wetlands 2021; WWF 2024). However, wetlands remain underrepresented in global conservation efforts and are severely understudied ecosystems in the context of global biodiversity loss (Kingsford et al. 2016). We lack detailed understanding of historical trends in wetland-associated biodiversity loss and the processes driving local to global species extirpations, which is critical to inform global policy agendas and to better target future conservation efforts (Yi et al. 2024).

This PhD will collate different lines of biodiversity data from the scientific literature, grey literature and historical archives, and capitalise on readily available multi-species datasets (e.g. Living Planet Database, BioTIME) to develop a world-first database of global population changes and local extirpation events for wetland-associated species (terrestrial and aquatic vertebrates, invertebrates, fish, plants). The student will then develop and implement various quantitative approaches to analyse this novel dataset, from geospatial analyses (cloud-based remote sensing) of target wetland-specific threats and spatial and functional change over time to phylogenetic regression models of ecological traits associated with resilience, and spatiotemporal scenario forecasting of potential future wetland biodiversity change. The research will provide new understanding of the resilience potential of wetland-associated biodiversity to future environmental changes and identify regional and taxonomic wetland conservation priorities globally.

The PhD will address four major goals, each constituting a publishable research chapter, to:

1. Quantify past levels and rates of wetland biodiversity change, advancing our understanding of the taxonomic, phylogenetic and regional consequences of wetland degradation globally.
2. Identify and quantify the major threats and drivers of global wetland spatial and functional change and associated biodiversity loss, quantified with large-scale cloud-based remote sensing of target wetland-specific areal and functional change (e.g., Lee et al. 2021).
3. Identify the life history and functional traits of wetland-associated species associated with resilience to change and perturbations, and how these traits may also be associated with global extinction risk (i.e., based on the IUCN Red List).
4. Evaluate the loss of taxonomic, functional and phylogenetic diversity under possible future scenarios of anthropogenic threat profiles and associated wetland change, to inform future global wetland conservation priorities (e.g., taxonomic, regional).

Training opportunities: 

The student will receive training on LPI methodologies, statistical, phylogenetic and scenario modelling, and cloud-based remote sensing at IoZ, on macroecological and functional trait analyses, and approaches to address bias and uncertainty in big datasets at University of Reading, and on integration of biodiversity measures into conservation-relevant research across both institutions. The student will work with CASE partner ZSL (Estuaries & Wetlands) to develop a framework streamlining project aims and outcomes with conservation project planning for species and ecosystem recovery. This will enable the student to develop a collaborative network and directly support the work of real-world wetland conservation practitioners. 

Student profile: 

This project would be suitable for students with a degree in Ecology, Biodiversity, Environmental Science, Applied Ecology/Conservation Science, Data Science, or a related field. Experience with statistical/numerical modelling and/or remote sensing and GIS would be highly beneficial. Familiarity with wetland ecology would be useful but not essential. 

Please note: if the studentship is awarded to an international student, the project will be hosted at the University of Reading under lead supervision of Manuela Gonzalez-Suarez. This is to comply with visa regulations. An international student would be expected to travel to the Institute of Zoology in London regularly to meet with the co-supervisor. In addition, please be aware that an international student based at the University of Reading would not be eligible for the London weighting allowance.

Co-Sponsorship details:

This project will receive a CASE award from the Zoological Society of London

References:

• Convention on Wetlands. 2021. Global Wetland Outlook: Special Edition 2021. Secretariat of the Convention on Wetlands, Gland, Switzerland.
• Davidson NC. 2014. How much wetland has the world lost? Long-term and recent trends in global wetland area. Marine & Freshwater Research, 65, 934-941.
• Kingsford RT, et al. 2016. Wetlands: conservation’s poor cousin. Aquatic Conservation, 26, 892-916.
• Lee CKF, et al. 2021. Mapping the extent of mangrove ecosystem degradation by integrating an ecological conceptual model with satellite data. Remote Sensing, 13, 2047.
• 2024. Living Planet Report 2024 – A System in Peril. WWF, Gland, Switzerland.
• Yi Q, et al. Global conservation priorities for wetlands and setting post-2025 targets. Nature Communications Earth & Environment, 5, 4.
• Zedler JB, Kercher S. 2005. Wetland resources: status, trends, ecosystem services and restorability. Annual Review of Environment & Resources, 30, 39-74.