The King of Lichens

On a bright spring morning a group of people gathered in an old farmyard. Dressed to keep out the Dartmoor breeze and equipped with small hand lenses they set off along one of the many ancient walled tracks that cross the landscape around the East Dartmoor National Nature Reserve. Within minutes the sky had darkened and the group huddled against a barn wall until the April shower had delivered its payload of sleet, revealing another pleasant blue sky. This was the second day of two when Brian and Sandy Coppins, well respected lichenologists, were in the area to train would be conservationists and cascade their knowledge to other local ecologists. The study of lichen can’t be rushed and the gentle walk continued with a discussion in a small gateway, looking at the variety of life thriving on a decaying tree stump. Each of the group were getting their eye in, studying fragments of bark, using their lenses to take a close look at the many forms and colours of lichen. On the other side of the gateway a boulder of granite displayed an entirely different group of species. The small Cladonia, a pixie cup, sparkled in the miniature world viewed through the hand lens. Next to it was a dog lichen, as different in appearance with dog-toothed ‘rhizines’ on the back of it, but another specialist of this particular micro climate. One of the group pointed out that “lichens are very fussy and particular about where they grow”.

Lichen is more visible before the oak leaves are fully open
Lichen is more visible before the oak leaves are fully open

Just along the hedge bank, the branches of an ancient oak were clad in a coat of beard lichen, in this case it was Usnea cornuta, one of the indicators of fresh air that is relatively common in this valley. At this time of year these lichens are clearly visible before the oak leaves cover and shade them as the summer progresses. In the next meadow up the hill the variety of lichen species was keeping the atmosphere of discovery alive when the more experienced members of the group could show the learners what to look for. Gathered round one of the experts, a group was listening as she described “it’s a pretty one, not very big and fairly widespread but you can see the script pattern. That is why it is called a phaeographis”. She continued to explain “the one next to it is a Physcia aipolia, it’s one of the jam tart lichens”.

The search for lichen - Physcia aipolia showing its fruiting parts, the jam tarts
The search for lichen – Physcia aipolia showing its fruiting parts, the jam tarts

In the corner of the same field, on a low hanging blackthorn bush, the golden jam tarts of a Xanthoria lichen glowed in the sun. This was a bit of a surprise as it is one of the species that tolerates high levels of nitrogen and can indicate pollution. As the group looked around they noticed that they were standing in the corner of the field commonly used by the resident ponies for shelter and they had ‘enriched’ the soil. Only paces away on another blackthorn bush there was no sign of the Xanthoria but the Usnea cornuta had returned, demonstrating what a sensitive air quality indicator lichens can be.

Blackthorn along a field boundary
Lichen can be a sensitive indicator of air quality

Escaping the chill wind on the ridge, the group all moved down to the next sheltered field where a magnificent ash tree stood. The lichenologists all made a beeline for it and spent some time focussing their lenses all around the trunk. A number of interesting finds were reported including the delicate pale foliose ‘leaves’ of a Normandina lichen, nestling in the protected deep bark crevasses.

The day of exploration continued back at the woodland centre; a make-shift lichen laboratory. With various microscopes available the experts in the group exposed further fascinating levels of magnified detail of these intriguing organisms.

robyn and james at work 2

Studying a leafy ‘foliose’ lichen at 20 times magnification, a tiny parasitic fungus was visible. Dave Lamacraft from the Plantlife charity explained how “all these species rely on each other for survival and ‘lichenicolous’ fungi live exclusively on lichens”. Looking at a cross section of a crustose lichen collected earlier that was magnified 400 times, a microscopic lichen spore was clear to see, even at 25 microns in length (one micron is a thousandth of a millimetre). When studying lichens, the closer you look, the more you see.

Brian, Albert, Dave and Sandy discuss the management plan at Hisley Wood
Brian, Albert, Dave and Sandy discuss the management plan at Hisley Wood

The following day, Brian and Sandy Coppins walked through Hisley Woods with Dave Rickwood of the Woodland Trust and Albert Knott of Natural England to discuss the woodland management programme. They looked at work already done and what would be needed next in order to favour the lichen and maintain the status of the SSSI. Discussions around the protection of veteran trees, the ancient archaeological remains and the gradual transition from planted conifer to a wilder and more natural woodland were all continued on from the last time Brian and Sandy visited the valley. The level of expertise is invaluable to the nature reserve management team and, where possible, they draw on some of the best scientific minds in the country. Albert concluded “that’s why Brian is the King of lichens!”

Words and images – Matt Parkins

The Woodland Trust and Natural England are working in partnership under the HLF funded Moor than meets the eye project. Together they manage the East Dartmoor NNR, assisted by others including and the local land owners around the Bovey Valley and Plantlife, the national conservation charity protecting wild plants and fungi.

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