This photo of an oak tree in Area Z, shows acorns which have developed abnormally around the larvae of knopper gall wasps. Not all acorns are affected, so the wasps' reproductive process causes no real harm to the tree.
(Area Z is the site currently being developed for burial in Camberwell Old Cemetery.)
There's information on the RHS website about the different species of gall wasps which use oak trees.
https://www.rhs.org.uk/advice/profile?PID=803
Hard to believe after the few days of heavy rain but the grass in the Camberwell Old Cemetery was being strimmed to bare earth in many areas as seen on our Camberwell Cemeteries Working Group AKA Friends of COC walk at the end of May. We have asked several times for this not to happen to no avail. In the vicinity of Area Z we saw these blue pipes sunk into the earth but with little respect for the nearby gravestones.
Chainsaws and wood-chipping heard and seen in COC Area Z on 22nd March. Woodchips being moved out of Area Z.