Please see photos of what I believe to be a graft union on a mature copper beech. The tree is 20m high, with a well balanced crown spread. Located in a private garden and currently surrounded and sheltered by other trees. Some of these companion trees may be removed and I am considering how the beech will stand up to the exposure.
Having referred to Lonsdale (Tree hazard assessment and management, 1999) this tree appears to present similar external signs of graft incompatibility as shown