MALHAM Tarn proved to be a well chosen site for the spring get together of the British Lichen Society after members discovered a very rare example of the organism. Lesley Tate reports
A RARE species of lichen only twice before recorded in England has been discovered at Malham Tarn by experts and enthusiasts in the field.
Lichens can be seen all over Craven - they are brightly coloured patches of growth and appear on rocks, trees, walls and even gravestones.
They are made out of fungi and algae, and together they are able to grow in stressful places where neither could grow by themselves.
Although they may look like plants, with tiny, leafless branches, they are not plants. They may also resemble peeling paint, or other growth forms.
They may be long lived, with some species considered to be amongst the oldest living things, and are among the first things to grow on fresh rock exposed following a landslide.
Their long life-span and slow and regular growth rate of some lichens can be used to date events.
The British Lichen Society is made up of people who want to study and protect such organisms - and its decision to stage its spring workshop at Malham Tarn Field Centre proved very successful.
Over more than a week, members went searching for species growing on limestone in the area.
And on the very first day, they discovered the rare Sclerococcum griseisporodochium just 200 metres from the centre and recorded only twice before in England.
The group, of about 20 society members, included eminent lichenologists, Dr Allan Pentecost, president of the British Lichen Society, and Dr Brian Coppins, a former lichen specialist at the Royal Botanic Garden, Edinburgh.
Dr Pentecost gained a love for Malhamdale when he attended a university field course from Imperial College, London, at Malham Tarn in 1969.
But he had gained an interest in lichens much earlier than that. Both he and Dr Coppins were taken on a field course to the Scottish island of Handa while studying at Tunbridge Wells Technical School for Boys - a trip that sealed for both of them a life long interest in lichens.
“Every walk in the countryside turns a few hours of exercise into a voyage of discovery," said Dr Pentecost.
During their stay at the field centre, the group walked down the valley to Malham Cove and on the way were able to share with the many passing walkers how to look at lichens through magnifying glasses.
They also explored some old lead mine spoil high above the field centre, and visited Lower Winskill Farm where farmer and archaeologist Tom Lord helped them compare lichens growing on walls of different ages.
There are almost 2,000 species of lichen in Britain, and about 950 lichen and associated fungi have been found in Yorkshire - although it is believed only 756 are still growing in the county.
In 2001, Dr Pentecost and Professor Mark Seaward, of Bradford University, carried out a study of lichen within a 5km radius of Malham Tarn and recorded 346 species - including 48 from old records.
As a result of findings during the spring workshop, the list will be increased, and it is 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.
An introductory day to lichens will be held at Malham Tarn Field Centre and led by Dr Pentecost on Saturday, May 20. It will be followed by a more advanced, three day course again at the field centre, from July 7 to July 10.
People can also find out more about lichen via the Open Aire Laboratories (OPAL) website. OPAL is a UK wide initiative which aims to encourage people to learn more about nature.
The Lichenologist, produced by the British Lichen Society, is distributed to universities around the world.
To book a place on one of the lichen courses in Malham, telephone the field centre on 01729 830331.