Supervisory Team:
Lead Supervisor: Bernd Hänfling (University of the Highlands and Islands)
Stakeholder Supervisor: Sarah Henshall (Cairngorms National Park Authority)
Co-Supervisor 1: Frances Orton (Heriot Watt University)
Co-Supervisor 2: Cédric Laizé (UK Centre for Ecology & Hydrology)
Project Description: Background
Riparian ecosystems are biodiversity hotspots that underpin river health, water quality, and flood regulation. Across the UK, these systems are increasingly degraded by multiple, interacting stressors that compromise their ecological integrity and resilience. Hydrological alteration from river regulation, drainage, and abstraction has reduced floodplain connectivity, while nutrient enrichment from agriculture and wastewater drives eutrophication and vegetation homogenisation. Historic channel modification and ongoing land-use intensification have simplified physical habitat structure and increased sediment and pollutant delivery. Invasive non-native species, such as Himalayan balsam, further destabilise riparian zones, and climate change amplifies these pressures through more frequent droughts and floods. Together, these stressors cause biodiversity loss, functional decline, and reduced ecosystem service delivery. River restoration programmes, such as those led by the Cairngorms National Park Authority, offer potential solutions, but their effectiveness must be robustly evaluated.
Aims and Objectives
This project aims to understand how multiple stressors shape the physical condition and biodiversity of riparian wetlands and to identify indicators of resilience and recovery. Specifically, it will:
Quantify physical and chemical stressor gradients across riparian sites.
Assess biodiversity patterns across trophic levels using environmental DNA (eDNA) metabarcoding.
Link stressor intensity, habitat condition, and biological structure to identify key drivers of degradation.
Develop and validate eDNA-based indicators of ecological condition for monitoring and restoration.
Integrate multi-stressor and biodiversity data into a predictive framework for resilient landscape design.
Research Approach
The project will combine hydrogeomorphic assessment, field surveys, and eDNA metabarcoding to assess riparian condition.
Physical habitat will be characterised using industry standard methodologies (e.g. RHS), combined with remote sensing and GIS analysis of connectivity, channel complexity and land use. eDNA from water samples will provide multi-taxa biodiversity profiles, including invasive species detection (e.g. alpine newt, signal crayfish). Multivariate modelling will link stressor data with eDNA metrics to identify thresholds, indicator taxa, and resilience patterns. The outcome will be a scalable, eDNA-informed framework for monitoring and guiding riparian restoration across UK landscapes.
What do you need to know:
This project combines field ecology, spatial analysis, and cutting-edge molecular techniques to assess how multiple stressors influence riparian wetland biodiversity and resilience. The student will work across disciplines, linking physical habitat assessments, environmental DNA (eDNA) based biodiversity assessments, and environmental data analysis, to develop innovative monitoring tools for restoration and policy application. The supervisory team provides exceptional expertise and complementary strengths: Bernd Hänfling (UHI) in eDNA and aquatic biodiversity; Frances Orton (HWU) in freshwater and amphibian ecology; Cédric Laizé (UKCEH) in environmental modelling and stressor analysis; and Sally MacKenzie (CNPA) in applied conservation and restoration management, ensuring comprehensive scientific, technical, and applied guidance throughout the project.
What expertise and skills will the student develop?
The student will develop a broad and interdisciplinary skill set spanning field ecology, molecular biology, spatial data analysis, and environmental management. They will gain hands-on experience in riparian and wetland field surveys, including River Habitat Survey (RHS) and hydrogeomorphic assessments, alongside advanced training in eDNA sampling, laboratory processing, and metabarcoding bioinformatics. Analytical skills will include multivariate statistics, geographic information system (GIS), and modelling of stressor–biodiversity relationships. Through collaboration with ECOWILD partners, the student will also develop science–policy communication, project management, and stakeholder engagement capabilities. Together, these skills will prepare the student for leadership roles in environmental research, conservation, and evidence-based ecosystem management across academia, government, or applied sectors.
Why is the project novel?
This project is novel in integrating environmental DNA (eDNA) approaches with physical habitat assessments to quantify the impacts of multiple, interacting stressors on riparian wetlands. While most studies address single pressures or use traditional biodiversity surveys, the project applies multi-taxa eDNA metabarcoding to capture comprehensive biodiversity responses across trophic levels. By combining eDNA data with physical habitat and stressor metrics, the project will identify molecular indicators of ecological condition and resilience. This integrated, scalable framework represents a step-change in how riparian ecosystem health is monitored, providing an innovative tool for evidence-based restoration and policy implementation in UK wetlands.
What real-life challenge does it address?
This project addresses urgent, real-life challenges in providing the evidence basis for managing and restoring riparian wetlands that are increasingly degraded by multiple, interacting human pressures, including altered hydrology, nutrient enrichment, habitat modification, and climate change. These stressors undermine biodiversity, water quality, and flood regulation, yet are difficult to monitor and manage effectively. Current assessment methods are often labour-intensive, fragmented, and limited in scope. By developing an eDNA-based, multi-stressor monitoring framework, the project provides a powerful new approach for detecting ecological change, guiding nature recovery and restoration efforts, and supporting UK policy goals on water quality, biodiversity net gain, and climate resilience.
