A DISEASE threatening to devastate the UK’s ash trees has been confirmed in North and East Yorkshire, as a local expert has warned of an “ecological catastrophe”.

Cases of Chalara or ash dieback have been confirmed in woodlands at a recently planted site near York, just north of Tadcaster and at another site between Thirsk and Masham. Infection has also been confirmed north of Market Weighton and on the coast between Bridlington and Hornsea.

The latest figures show the disease, caused by the fungus Chalara fraxinea, has been found in 61 locations in the countryside, as well as 39 planting sites and 15 tree nurseries, a total of 115 sites across the UK.

Rob Stoneman, chief executive of the York-based Yorkshire Wildlife Trust, said he was extremely worried about the consequances for the region. He said: “Ash is a massive component of the natural woodland scenery in Yorkshire, particularly in the upland. If we were to lose our ash trees we would be looking at an ecological catastrophe. We would see half the trees dying in our woodlands.”

The Chalara fraxinea fungus, which causes leaf loss and crown dieback and can lead to tree death, has wiped out 90 per cent of ash trees in some parts of Denmark and is becoming widespread throughout central Europe.

At Hovingham Estate Sir William Worsley said they had no confirmed cases but he said he was worried about the potential consequences for the 900 acres of woodland, 12 per cent of which is made of ash trees. He said: “I am hopeful we won’t get it. I’m very concerned about it because of potential devastating consequences to the landscape.”

About 100 experts yesterday attended a summit to discuss how to tackle ash dieback disease with a Chalara action plan due to be published today. There are fears the UK’s ash trees are facing a similar fate to its elms, which were destroyed by Dutch elm disease in the 1970s.