Oak trees in Britain have long suffered from dieback disorders but a new disease called acute oak decline is currently causing particular concern. A typical symptom of the disease is dark, sticky fluid bleeding from small cracks in the bark on the trunk of the tree. This stem bleeding may be extensive, with as many as 20 or more bleeding patches on an infected tree, and the canopy may become thin as the tree approaches death. Some trees die within four or five years of the onset of symptoms. Bacteria are thought to be the cause of the stem bleeds and tests to confirm this are underway. Currently, the condition appears to be most prevalent in the English Midlands but cases have also been reported in Wales. Woodland managers should survey, record and monitor infected trees and take the appropriate recommended action, which may include felling diseased oaks. Felled material should not be removed from affected sites unless the bark and sapwood have been removed and destroyed.
A4 leaflet | 6 pages | colour | online only