Lichens are so omnipresent that few people stop to admire the incredible variety among them. I myself was guilty of paying them little more attention than a cursory glance, before I, with a team of other Natural Sciences undergraduates from the University of Exeter, teamed up with Natural England for one of our modules.
Two of the key lichen species that we recorded at sites across Dartmoor – Usnea articulata (left) and Bryoria fuscescens
On our first venture to Dartmoor, we visited Hunter’s Tor, where we learnt to identify Bryoria fuscescens, Usnea florida and Usnea articulata. On this eye-opening day, where we were forced to acknowledge that lichens may be a lot cooler than GCSE biology makes them seem, we also began to form the bones of a methodology that would serve us for the rest of the term, across the various sites we visited. As multidisciplinary students, we were keen to ensure reproducibility between sites, and over the years, to allow for a more comprehensive sampling effort of these species across Dartmoor than had previously been undertaken.
Usnea florida (pictured) and Usnea articulata were surveyed along walking transects – the blue line shows survey transect 3&4 through Hisley and Rudge Wood
But why these species? A study from 30 years ago, entitled ‘Lichens of the Dartmoor Rocks’ (V. J. Giavarini, 1990) had noted the presence of these species at various sites across Dartmoor, and the sensitivity of these species to nitrogen and other pollutants makes them an interesting indicator of air quality. We hypothesised, that an absence of these lichens where they had previously been noted, could link nicely to data we collected from DEFRA on air quality from their Yarner Wood monitoring station.
As part of the assessment for this module, we were required to produce a 15-minute video summarising our activities from the term, and our findings. We had a lot of fun creating this, taking panoramic shots of the stunning landscapes, selfies with adorable dogs and of course making the odd bit of scientific content to accompany these! For all who are interested, you can watch the video on this link, or click on the image below https://youtu.be/s402ispTT_8
While the lack of previous quantitative studies such as these makes it difficult for us to draw hard conclusions about the state of these lichens on Dartmoor, we hope we have provided a comprehensive record, from which future comparisons will be possible. In conjunction with the local and national trends in air quality, and perhaps combined with increasingly sophisticated modelling techniques, we hope that our lichen distribution data will begin to make sense in relation to influencing factors such as altitude, aspect, management and farming practices.
Annotated photographs, such as this one of Bell Tor, will help inform future surveyors when they revisit these sites
As our project comes to a close, we would like to say a huge thank you to Albert Knott, from Natural England for giving us this opportunity; to Barbara Benfield, for sharing her expertise; and sincerely to all the volunteers, without whom this would not have been possible. From helping with identification, transportation, pointing us in the right direction (literally and metaphorically!) and showing us the ropes, these people are invaluable. A special shout-out to Natural England volunteer Janet seems appropriate, as she tallied up the most trips out with us, and her Usnea spotting abilities are the stuff of legends.
By Georgia Gowing – Natural Sciences student, University of Exeter
If you have been inspired to to find out more about lichens …The Woodland Trust and Natural England are working together with Plantlife to develop an exciting new project in the Atlantic woodlands of the SW, with opportunities to learn more about our wonderful woodland heritage and its plant life, including lichens, mosses and liverworts. You can visit the project page here Building Resilience in South West Woodlands.