03/11/2012 14:10
Most UK ash trees will be diseased within 10 years
Ash dieback disease will spread across the UK by around 20 miles a year, infecting most of the country's 90m ash trees within a decade, the government was told Friday at a crisis meeting with its leading environment advisers, the Guardian said.
It is feared many more clusters will be identified in the next year and that spores from the fungus will spread from the east of England and Scotland to eventually cover Britain – in some cases carried on people's clothes.
The grim picture was set out by Ian Boyd, chief scientist with the Department for Environment, Food and Rural Affairs, at a national emergency Cabinet Office briefing room (Cobra) meeting led by the environment secretary, Owen Paterson.
Even if the native ash tree cannot be saved, the meeting was told, such is the tide of similar deadly plant diseases now coming into Britain on millions of imported plants every year that drastic measures like long quarantine periods and passports for all plants may be needed.
In the gloomiest prognosis yet made of the disease now known to be infecting trees in Scotland, East Anglia and possibly Kent, Boyd warned ministers that trees cannot be vaccinated, and the airborne disease would be too expensive to treat chemically. He said the spores first found in Britain in March can be spread even by the moving of leaves.
But some ash trees are likely to have natural immunity, he said. "Older trees infected with ash dieback may weaken but die of other diseases. Trees are more likely to be affected in forests than if they are isolated," he said.
The government will hold a tree summit next week at which proposals will be discussed by the forestry industries, scientists, charities and nurseries. The most radical suggestion is expected to be for more rigorous border checks on the billions of trees and plants imported into Britain and Europe from around the world every year for parks, gardens, woodlands and forests.