We went for a walk in behind Picton through this lovely beech forest. Many of the trees looked like they were covered in black soot. It is a black sooty fungus on the trunks of the trees. This fungus is nourished by liquid honeydew which is produced by a native scale insect living under the bark of the tree. This honeydew scale insect produces vast quantities of sugary syrup and this is food for insects, bats, lizards and honey eating birds. Beech trees are so elegant.
Ian