Lichens at Roswell Pits
We were very fortunate to have a visit by Mark Powell, Louise Bacon, Catherine Tregaskes and Paula Shipway of the Cambridge Lichen Group. On the 9th April 2017 they carried out a lichen survey on Ely wildspace and the City of Ely Cemetary.
Seventy-seven taxa were recorded from various habitats at Roswell Pits. Of these three are lichenicolous fungi; an under-recorded group of organisms that infect lichens. One of these, Pyrenochaeta xanthoriae was added to the British list in May 2016 and the occurrence at Roswell Pits is new to Cambridgeshire and the third record for Britain.
The most notable lichen community occurs on the trunks of old stubby trees on the bank beside Springhead Lane. A particularly notable example of this community occurs at TL5521.8050 where Bacidia viridifarinosa forms extensive pale green sorediate patches at the bases of the trunks. B. viridifarinosa is known from just one other site in Cambridgeshire, in Madingley Wood.
At the cemetery, nothing of particular note was encountered, although some sixty-one taxa were recorded. The old sandstone are thought to retain a toxic legacy from their decades during levels of coal-based atmospheric pollution. The more recent stones provided clean sandstone surfaces after the sulphurous pollution had abated. Thus they supported different communities.