A Chance to Help Save Ash Trees
When ash dieback was first identified in the UK, predictions were grim. A fungal disease with the potential to wipe out most of Britain’s ash trees had arrived, and its spread seemed unstoppable. More than a decade on, researchers at Queen Mary University of London and the Royal Botanic Gardens, Kew are uncovering a more hopeful story, one in which ash trees are beginning to fight back, evolving greater resistance through subtle but powerful genetic change.
When ash dieback—a deadly fungal disease that kills ash trees—was first detected in the UK in 2012, the outlook was bleak. Journalists warned that up to 95% of Britain’s ash trees could ultimately be lost. Since then, the fungus has spread to every corner of the British Isles, threatening one of the country’s most iconic native trees in woodlands, parks and hedgerows across the country.
This unfolding ecological crisis has also created a rare scientific window into evolution in action for researchers at Queen Mary University of London (QMUL) and the Royal Botanic Gardens, Kew. As Richard Nichols, Professor of Evolutionary Genetics, explains, a “tragedy for the trees has led to a revelation for scientists — allowing us to show that thousands of genes are contributing to the ash trees’ fightback against the fungus.”
The research teams have been tracking ash populations over time, combining long-term field monitoring with detailed genetic analysis. By studying trees in British woodlands, including a closely monitored site in Surrey, the scientists detected subtle shifts in gene frequencies across generations. These changes suggest that younger trees are inheriting genetic variants that help them survive infection better than their predecessors.
Richard Buggs, Professor of Evolutionary Genomics, argues that ash trees are not doomed by the disease. Instead, they are beginning to evolve greater natural resistance, offering a rare piece of good news after more than a decade of loss. He stresses that we can use practical measures such as shielding young trees from grazing animals and using the most resilient individuals in future planting schemes to greatly strengthen this natural recovery, saying “We have fresh motivation to look after our ash populations, to protect them from other problems like deer browsing, and to let nature take its course and evolve trees with more resistance,”.
Together, the work of the QMUL and Kew scientists suggests that ash trees may yet remain part of Britain’s landscape — not unchanged, but tougher, better adapted, and carrying the promise of renewal.
The research on ash dieback is part of a wider portfolio of projects at Queen Mary University of London’s Centre for Functional Genomics and Centre for Biodiversity and Sustainability, where scientists are working to tackle the global challenge of ecosystem degradation by developing solutions that strengthen ecosystem resilience for the future.
Richard Buggs is part of the Centre for Functional Genomics and teaches on the MSc Plant and Fungal Taxonomy programme and the MSc Biodiversity and Conservation programme.
Centre for Functional Genomics: https://www.seresearch.qmul.ac.uk/cefg/
Centre for Biodiversity and Sustainability: https://www.seresearch.qmul.ac.uk/cbs/
Metheringham, C.L., Plumb, W.J., Flynn, W.R., Stocks, J.J., Kelly, L.J., Nemesio Gorriz, M., Grieve, S.W., Moat, J., Lines, E.R., Buggs, R.J. and Nichols, R.A., 2025. Rapid polygenic adaptation in a wild population of ash trees under a novel fungal epidemic.