Killer disease found in Scottish ash trees as import ban begins

A DISEASE threatening the future of ash trees has been identified in Scotland, the Forestry Trust has said.

Chalara ash dieback could have a dramatic impact on wildlife and the environment if it spreads beyond the initial identification site in Kilmacolm, Renfrewshire.

The UK government is to ban importing ash trees and bring in tight movement restrictions from today, as part of efforts to stop the spread of the fungus.

The disease was first identified in the UK in East Anglia and the discovery has increased fears that ash trees face the same fate as the elm, which was devastated by Dutch elm disease in the 1970s.

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

Dr Steve Woodward, a researcher at the University of Aber­deen who specialises in plant diseases, said: “Around 30 per cent of our woodland trees are ash, and it hosts lots of insects, non-damaging fungus and, of course, birds and bats nest in it, so it is very important ecologically and environmentally.

“It is extremely difficult to stop it spreading. The only glimmer of light on the horizon comes from Denmark, where they tested lots of different batches of ash from different provinces and they found a few types that proved to be resistant.

“So there is a possibility there will be some trees left if the chalara spreads widely, but we are talking tiny numbers really. It spreads through spores that appear on leaves or young twigs that have died.

“The fungus is in the leaf stock over winter and when it warms up in spring it produces these little spores – small discs – that are blown around, and if they land on suitable tissue they will infect the tree.”

The Forestry Commission said it was surveying ash trees in East Anglia, and if the problem was widespread the focus would be on preventing further spread.

The commission said an import ban and movement restrictions were sensible moves to try to minimise the spread of the disease.

The Horticultural Trades Association said it first raised the issue of ash dieback in 2009, calling for import restrictions, but at the time the disease was thought to be caused by a fungus already endemic in Britain, making a ban ineffective.

Environment Secretary Owen Paterson has denied that UK ministers were slow to react to the outbreak.

Mr Paterson said: “We will bring in a ban on Monday. I have already prepared the legislation, and we’re ready to go. The evidence is clearly there.”