The fungus Chalara fraxinea was first identified in the UK in February 2012 in a tree imported from the Netherlands to a nursery in Buckinghamshire. It has now been found at 136 sites linked to imported plants and a further 155 sites in the wider environment, which government scientists think were infected by wind-blown spores from continental Europe. The disease has devastated ash trees in many countries including Denmark where 90% have been infected.
The UK’s control plan is based on four measures – “reduce, develop, encourage and adapt”, said Prof Ian Boyd, chief scientist at the Department for Environment, Food and Rural Affairs (Defra). He said the aim was to reduce the spread of Chalara, develop new control measures and resistant varieties, encourage the public and industry to help out and adapt the nation’s forests to the inevitable changes. More than 13% of the country’s broad-leaved woods are dominated by ash trees.