9 Nov 2012

Ash dieback cannot be eradicated, UK says

The environment secretary wants it will not be possible to eliminate the fungus threatening to devastate UK ash trees and more ‘devastating’ diseases should be expected.

The environment secretary wants it will not be possible to eliminate the fungus threatening to devastate UK ash trees and more 'devastating' diseases should be expected.

There are 129 confirmed sites where ash dieback has been found, including 64 cases in woodlands. Going forward, there must be an overhaul of how the UK deals with forestry infections, Environment Secretary Owen Paterson said as he announced an action plan to combat the problem.

“The scientific advice is that it won’t be possible to eradicate this disease now that we have discovered it in mature trees,” he said. “However, that does not necessarily mean the end of the British ash.”

The Horticultural Trades Association is pushing ash growers to sue the UK government for damages, saying ash trees worth more than £2.25m must be destroyed and that could go higher if the disease cannot be stopped.

Genetic resistance

If the UK can find genetic resistance to the disease it may be able to restructure woodlands to make them more resilient.

“If we know a small number of trees survived the intense epidemic in Denmark there must be hope here,” Mr Paterson said.

The Chalara fraxinea fungus causes leaf loss and crown dieback and can lead to tree death in ash trees. It has already wiped out 90 per cent of ash trees in some parts of Denmark. There are fears that the UK’s ash trees facing a similar fate to its elms, which were destroyed by Dutch elm disease in the 1970s. There have also been problems involving plane mould in France and if that disease were to arrive in the UK it could affect many more trees.

The UK has ruled out cutting down and burning mature ash trees to stop the disease. Mature trees are valuable to wildlife.

Britain’s action plan will focus on tracing and destroying newly planted trees and those in nurseries, and better understanding the disease through research and surveying.

Ban on imports

Ministers have brought in a ban on importing ash trees from outside the UK to stop ash dieback spreading further from imported trees. But experts warn that the disease in mature woodlands is likely to have been wind-borne from the continent and little can be done to stop its spread.

The National Trust welcomed the decision not to chop down mature trees, and backed the commitment to destroy young plants, but said it was surprised the government believed it will not be possible to eradicate the disease.

“We should keep an open mind as to whether it may be possible to eradicate it, or at least contain it within the core area in the east,” Dr Simon Pryor, director of natural environment at the Trust, said.

Readers who are wondering how to spot ash dieback should click here.

Topics

,