My introduction to lichens
Ever wondered what those smudges of black, grey and yellow are on paving slabs? Marvelled at the delicate filaments of green and yellow on twigs and old branches? What exactly is a lichen? (and how do you even pronounce it?)
I am somewhat of a beginner in the field of lichenology – aware of a few of their weird and wonderful names like Xanthoria, Cladonia and Physcia – but with thousands of different species of lichen, how do you start trying to identify species in woodlands, gravestones and urban environments? I decided to book on the FSC “Introducing Lichens” course to find out.
As nearby Shrewsbury town Centre was filling up with Saturday morning shoppers, I and around 15 others arrived at Preston Montford Field Centre to learn about organisms that many people rarely give a second glance. We started the day with an informative and helpful talk about the basics of what a lichen is, an overview of the main forms they take, and the incredible range of habitats they occur in. Did you know that around 8% of the earth’s surface is covered in lichen? They are important indicators of air quality and, along with their essential role in absorbing large amounts of carbon dioxide, we humans have found uses for them in everything from the dye industry to perfumes and cosmetics and even cooking.
After the talk it was time to get outside into the delightful Shropshire sunshine. We found that even beneath our feet there were several different species of crustose lichen. We must have all looked quite a sight, lying down with our heads centimetres from the ground trying to peer at lichens on the paving slabs through our hand lenses!
Over the next few hours we explored the rural grounds of Preston Montford Field Centre hunting for lichens. We wandered across open fields with the Shropshire Hills and Welsh Borders in the distance, through woodlands with tall oak trees, past ponds and reed beds teeming with insects and aquatic plants, and admired the diverse communities that had colonised crumbling walls in the ruins of farm buildings.
The highlight of the day was discovering the plethora of lichens on an old boardwalk across one of the ponds. This was a real hotspot for lichen diversity and we found out about the subtle differences in the colour and appearance of the foliose “camouflage” lichens that covered this structure. Under the expert guidance of John Douglass, our very knowledgeable tutor, even the beginners amongst us were able to pick out three different species in what at first glance appeared to be the same leafy, brown covering on the boardwalk handles.
Back in the classroom after lunch and cake we turned our hands to try some lichen microscopy. Many of us had not looked down a microscope since biology classes at school. Being able to make a slide and see the spores and layers of algae and fungus in the lichen felt, for me at least, like quite an achievement.
At the end of the day, having just scratched the surface of what there is to know about lichens and their identification, there’s certainly a lot more for me to learn about these enigmatic organisms. But with FSC courses available on things like bryozoans, water beetles, otters and sphagnum moss, the incredible diversity and intricacy of the natural world is just waiting to be further explored.
Holly Woo, previous FSC customer and now FSC employee.
See our lichen courses for 2015 2016 dates will be available soon!
Tuesday, August 25, 2015