Overview

• Genomic analysis shows young ash saplings carry a higher frequency of resistance-linked variants compared with older trees
• Researchers at Marden Park wood in Surrey found natural selection has subtly reshaped thousands of genes to bolster dieback resilience
• Dr. Carey Metheringham warns that low genetic diversity and declining adult ash numbers could slow the pace of natural adaptation
• Scientists recommend selective breeding programmes and protective measures for saplings, such as deer exclusion, to accelerate full resistance
• Since its 2012 arrival in Britain, ash dieback caused by Hymenoscyphus fraxineus has killed millions of trees, threatening up to 85% of the native population and spurring Defra-funded research