Race to save Britain's oak trees from mystery disease that's 'bleeding them to death'... and the colourful beetle that could be to blame
- Thousands of oaks have already been affected by a mysterious disease
- It can kill the ancient trees within four years
- Government has ordered a huge survey across Britain to track the threat
By JASON LEWIS
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Mail on Sunday
Under threat: A classical country scene with a large Oak in the Lake District National Park near Hawkshead
The Government is spending £1.1 million on an emergency project to save ancient English oaks from a mysterious disease that is causing the trees to ‘bleed to death’.
Thousands across the UK have already been infected, with the disease so serious that oaks are being felled and their bark stripped and burnt to prevent it spreading.
One theory is that a beetle may be responsible for the threat to the historic trees.
Researchers are now involved in a race against time to develop a way to stop the disease that, once it takes hold, kills the oaks within four years.
The Government has ordered a huge survey of trees across Britain to try to understand and track the new threat. Many of Britain’s ash trees are already doomed by the rapid spread of a fungal infection.
Scientists are also trying to isolate and identify a bacteria found on the dying oaks that was previously unknown and might be behind the infection.
The three-year project is an effort to stem the spread of so-called ‘acute oak decline’, or AOD, which is identified by dark weeping patches on stems of older trees. Oaks more than 50 years old are at the greatest threat.
Researchers believe the disease may be linked to the oak jewel beetle because the diseased trees’ bark is often pitted with the insects’ distinctive D-shaped exit holes.
The beetle’s larvae have also been found in or near the ‘bleeding’ patches on the trunk of dying trees. It is not known if beetles are attracted to the scent of the infected trees or if they are carriers of the disease that is killing them.
Attack: The oak jewel beetle that feeds on oak timber
Using advanced sequencing technology, scientists will analyse the DNA of bacteria, fungus and insects found on healthy and infected trees to isolate the cause.
The Forestry Commission and bioscience experts at Bangor and Cambridge Universities are leading the project, which will take samples from up to 200 woodlands.
Estates belonging to the National Trust are among the hardest hit. At Blickling Hall in Norfolk, the majority of the oaks within its 950 acres of historic parkland are suffering from the disease. Ancient trees at Attingham Park in Shropshire are also affected.
According to a Forestry Commission document, estate workers should ‘strip the outer bark and sapwood of heavily infected and dying or dead trees after felling and burn on site’.
‘Rapid destruction of stripped bark is recommended to prevent the possibility the disease spreading,’ it adds.
Mysterious disease: Thousands of oaks have already been affected, which kills them within four years
Dr James McDonald, from Bangor University, is carrying out DNA research using forensic science techniques pioneered in medical research to try to identify the bacteria.
He said: ‘It is affecting older trees, some hundreds of years old, and whatever is behind it is causing the decline of something that has been here for so long, is much loved, and is difficult, if not impossible, to replace.
‘It is a very complicated issue. It could involve new bacteria that have been isolated from the lesions on the stems or the oak jewel beetle. We are looking at their involvement but both could be passive bystanders in the process. We don’t know.’
Dr John Morgan, head of the Forestry Commission’s Plant Health Service, said: ‘We are determined to do everything possible to protect our trees. AOD is a complex condition and this new funding will enable us to better understand it, and the number and distribution of trees affected.’
