Midland Forestry Case Study Acute Oak Decline
In recent years there was large amounts of publicity of the spread of Sudden Oak Death from the USA to the UK but the more worrying threat of Acute Oak Decline (AOD) has not yet received the same level of publicity in the mainstream media.
AOD affects mature oaks (greater than 50 years old) of both native species, pedunculate or English oak and sessile oak. The first indications of the disorder are the appearance of a dark fluid exuding from the small cracks in the bark on the host trees stem.
This dark fluid often runs down the stem and at certain times of the year may dry and cake onto the stem. No other symptoms may be visible until the tree approaches death at which point the canopy may begin to thin noticeably.
AOD can lead to tree death within 4 to 5 years. The number of trees affected is unknown but the condition appears to be most prevalent in the Midlands.
This is a new disorder and a full understanding of the causative agents have yet to be established though there is a mounting body of evidence that bacteria are responsible.
Chris Shortis Dip. Arb. (RFS), M. Arbor A.
Midland Forestry Ltd
Treatment for infected trees is precautionary at present and the preferred option is to leave infected individual trees undisturbed as pruning work is likely to increase the risk of spreading the disorder and may reduce the trees ability to overcome the disorder.
Heavily infected and dead trees should be felled and ideally disposed of on site, or at least the bark removed and burnt on site. Felling and timber handling equipment must be disinfected after use.