In October several woodlands in East Anglia were found to have the ash dieback disease, chalara fraxinea. The Forestry Commission has provided a guide on how to spot it:
Symptoms of Chalara fraxinea can include
Wilting and black-brownish discolouration at the leaf base and midrib
Dieback of shoots and twigs
Small lens-shaped lesions or necrotic spots on the bark of stems and branches and enlarge to form perennial cankers
Underneath the bark lesions, the wood has a brownish to grey discolouration
Trees with withered tops and shoots
Heavily affected trees have extensive shoot, twig and branch dieback and often prolific epicormic shoots.