Rare lichen found at Malham Tarn Field Centre

Article and photographs by YNU member Judith Allinson

Have you ever noticed the brightly coloured patches of growth that occur on our rocks, walls, trees and gravestones?  These are lichens.  A lichen consists of a symbiotic association between a fungus and algae or cyanobacteria, which together are able to grow in stressful places where neither could grow by themselves.  The British Lichen Society promotes the study, enjoyment and conservation of lichens by running training courses, organising field meetings and publishing a journal, The Lichenologist, which is sent to subscribers around the world.

The British Lichen Society (BLS) chose to spend its 2017 Spring Workshop at Malham Tarn Field Centre on the 18th to 25th April.  It was led by two eminent lichenologists: Dr Allan Pentecost, current president of the BLS, and Dr Brian Coppins, former lichen specialist at the Royal Botanic Garden Edinburgh.  Twenty members took part in the workshop, visiting sites each morning to look for lichens growing on limestone.  On the very first day they discovered a rare species called Sclerococcum griseisporodochium that had only been recorded twice before in England - it was growing less than 200 metres from the Field Centre!

Other activities during this highly successful field meeting included a walk from Malham Tarn down the dry valley that leads to Malham Cove, where the group were happy to show many passing walkers how to look at lichens through hand-lenses, an exploration of some old lead mine spoil above the Field Centre at 1700ft (518m) and a visit to Lower Winskill Farm where farmer and archaeologist Tom Lord enabled the group to compare lichens growing on walls of different ages on his farm.

There are almost 2,000 species of lichen in Britain.  Over 950 taxa of lichens and associated fungi have been found in Yorkshire, but only 756 are thought to be still growing in Yorkshire.  Dr Pentecost and Prof Mark Seaward of Bradford University made a study of lichens within a 5 km radius of Malham Tarn in 2001 and 346 species were recorded, including 48 from old records.  This list will be increased after the April week. It is also possible that several of the specimens that they found on the week will be used in helping to give names to lichens that have not yet been named - yes there are new species to be found!

Allan Pentecost gained a love for the area when he attended a university field course from Imperial College at Malham Tarn in 1969, but he had gained an interest in lichens much earlier than that. Both he and Brian Coppins had attended the same secondary school and were taken on a field course to a Scottish island (Handa) whilst studying at Tunbridge Wells Technical School for Boys with their teacher John Charman. This shows the importance of encouraging children and young people to go on field trips.  Allan Pentecost said: “Every walk in the countryside turns a few hours of exercise into a voyage of discovery”

Brian Coppins, Allan Pentecost and Janet Simkin in Malham Dry Valley

(19th June 2017)