Credit: Forest Research
What happens to the tree?
Symptoms of acute oak decline are essentially normal tree responses to stress. Thinning of leaves on the crown is caused by a tree struggling to take up water and wet patches on the bark known as bleeds can be a response to drought.
If the stress is particularly severe or prolonged, the tree can reach a tipping point where it runs out of energy to get through the winter or fight off pests. These trees can die within a few years.