What is Acute Oak Decline?
Acute Oak Decline is a complex tree disease which has a major effect on multiple species of Oak trees. This particular disease causes dark coloured fissures that weep vertically down the stems of the Oak tree (as pictured to the left), as well as cracks within the bark to the stem. Unfortunately, this disease can rot the entire girth of the Oak, which prevents it being able to transport water and nutrients to the rest of the tree; later causing dieback within the crown of the tree. Subsequently, over time, this results in the tree becoming weak and eventually dying.
Acute Oak Decline can kill an Oak tree within 4-6 years of developing symptoms and will more commonly affects Oak trees that are located in warmer locations within the UK that are more prone to drought.
The cause
Acute Oak Decline is caused by three different types of bacteria which has been consistently found within the fissures/ bleeds on the stems of the Oaks. The bacteria associated with Acute Oak Decline is Brenneria goodwinii, Gibbisiella quercinecans and Rahnella victoriana. It has been found that on some trees that have Acute Oak Decline, the two-spotted buprestid beetle has been present, as they utilise the declining Oaks for habitat. Unfortunately, due to this beetles presence, it assists in the trees decline at an increased rate. This is due to the two-spotted buprestid beetles larvae’ wood-boring activity which damages the Oaks further.
What species are at risk?
Acute Oak Decline commonly affects the English Oak and the Sessile Oak, but has also been seen in Holm Oak, Bali Oak, Oriental White Oak, Red Oak, Pin Oak, Turkey Oak, Water Oak, Scarlet Oak and Pyrenean Oak. Acute Oak Decline will commonly affect the above Oak species in their mature years, however, younger specimens can also become infected.
How to manage it
Unfortunately, there isn’t any reversal for trees affected by Acute Oak Decline. However, it is recommended to monitor them and leave them in situ unless they are classed as a high health and safety concern. When it comes to tree surgeons carrying out any work on Oak trees affected by Acute Oak Decline, it is crucial that every tool that is used on the affected tree is thoroughly cleaned in order to follow biosecurity guidelines. This will then avoid passing the disease onto any other trees.
If you’re concerned about a tree within your property then please don’t hesitate to contact a member of our team who can help establish a plan of action.
