Scotland’s wildlife is amazing, but it's in crisis. We want to see greater protection for all nature and greater commitment to action on species recovery specifically, including for some of Scotland’s most iconic wildlife. In today’s blog Nora Casey, Senior Parliamentary Officer, tells us why they’ve picked Rainforest lichens as their favourite Scottish species.
Why are lichens important to Scotland?
Many lichens have become rare due to habitat loss and air pollution from industrialisation and intensive farming methods. Scotland has some of the few places in Europe where such lichens can still be found going strong, and without lichens those places would be less special and other species would suffer their loss.
Lichens have been used by humans for food and medicine and to dye clothing, including Crottle used in Harris Tweed and cudbear, a purple dye developed in Scotland, so they are part of our culture. Lichens are also used by scientists to measure heavy metals in the air.
Tell us about a time you saw a lichens in real life/up close?
I love seeing Graphis lichens– they’re very flat lichens that live on tree bark and their fruiting bodies look a little bit like wobbly handwriting. Some of them are rare and found in the west of Scotland. Any time I see a nice bushy lichen, I’m happy because it tends to mean the air quality is good. Walking around in a wood with no lichens, maybe because of pollution or because it was clear-felled at some point, is very sad once you’ve experienced what it can be like with them.
Where do lichens usually live?
One of the great things about lichens is that different species can live in almost every imaginable environment. You probably have some lichens near you almost anywhere in Scotland. However, a lot of them are not very pollution-tolerant, so in big cities you’ll only see a couple of kinds, including Xanthoria parietina, sometimes called Common Orange Lichen or Yellow Scale. To see more lichens, trees in old-growth forest or big rocks at the seashore or on mountains are a couple of places to look.
What do lichens need to survive/thrive?
Lichens need sunlight so that the alga or blue-green alga in the lichen can make energy from carbon dioxide in the air, just like plants. They grow best in damp conditions, which is one reason they do so well in Scotland’s rainforest. As mentioned above, most of them don’t like air pollution like nitrogen or sulphur, and because they grow very slowly, they usually aren’t great at coming back if their habitat is disturbed or lost. Beyond that, different kinds of lichen like different habitats, so some only grow on certain kinds of rock and some only grow on certain trees.
What’s a fun/surprising fact about lichens?
Lichens are partnerships between a fungus and either a small alga (tiny single-celled plants) or a blue-green alga, which is a kind of bacteria that can photosynthesise. Sometimes all three are part of the same lichen; in other cases, one fungus can form very different-looking lichens with an alga and with a blue-green alga. Lichens have been found preserved in amber.
Tree Lungwort and Green Satin Lichen on tree branches. Andy Hay
Can you tell us a short personal story about lichens?
My most memorable lichen encounters have been in Northern Ireland, where a friend of mine was working on a lichen survey in the early 2000s. I fondly remember weekends spent clambering around in steep hazel woods and chipping bits of rock off to take back to the microscope, then once we got back, the process of trying to identify samples from what the spores and other features look like. I remember seeing Lobaria pulmonaria, the Tree Lungwort, which is a very big leaf-shaped lichen, sticking out like a big oak leaf from tree trunks, and being completely gobsmacked.
Learn more about our #SaveScotSpecies campaign here, and pick your favourite species here. Don’t forget to send our digital postcard to your MSPs asking them to make species recovery a priority.
Main image: Tree Lungwort from Scotland’s rainforest. Oliver Moore