A blaze of colour in winter : Lichens
It could be easy to think there isn’t much colour in nature during wintertime. But surprisingly if you get a chance to really look there is actually millions of little blazes of shapes, textures and colours that are there growing extremely slowly all year round. They can be found on walls, rocks, bark, twigs and even on soil and that is the fascinating word of lichens.
What is a Lichen?
Lichens are a partnership made up of more than one organism. A symbiotic association between a fungus and an algae/and or a Cyanobacteria (known as photobionts). The fungus needs a food source whilst the photobionts require protection to survive. As the Photobionts are photosynthetic they provide a food source for the fungus made from the sun, water and air and in return the fungus provides them with a home and shelter! It’s a winning partnership!
The life of a Lichen
This group of fungi is extremely old. It is estimated to have evolved during the Carboniferous period (over 300 million years ago). With the very first lichens likely dating back to before the origin of land plants, when most of the biodiversity of our planet earth was in the sea!
Lichens take a long time to grow, only about 1-2mm per year! They prefer an established undisturbed place like ancient woodlands to live as then they have the time and space to grow there but can also be seen in many varied places around towns and cities too. They are very sensitive to air pollution so are a good indicator of that areas air quality and the overall health of the environment. Crusty species of Lichen are more hardy to pollution, with beardy species more delicate and only found in areas of cleaner air quality. It’s great to see so much Lichen here in the south side of Glasgow – our inclement climate must suit!
What to look out for?
Check out our wee video showing some of my local Lichens!
Lichens come in different shapes, textures and colours to look out for and can range in colour from white to yellow, green, grey or brown. Some species associate with different surfaces to grow on for example needing certain barks like the Ash Tree as it gets is more acidic (alkaline) with age. Others grow on rocks, or even directly on soil – in the video I was looking at a birch tree. Additionally using a magnifying glass if you have one will let you see so much more detail - a world in miniature!
Lichen Shapes to look for: bushy beards!, leafy pads, strap branches, crusty leaves & spots.
Lichens are non-parasitic and don’t harm any plants they live on. They are extremely valuable to wildlife as a source of nesting materials for birds and food and shelter to lots of invertebrates which in turn become food for other creatures feed on. A woodland rich in lichen supports more wildlife than any other. Threats to Lichen come from pollution and destruction of their habitat.
Lichens have adapted to live in some of the most inhospitable environments all over the world from arctic, to desert to coast. Fungi’s morphing into lichens (Lichenisation) and hosting the photobionts is an ecological strategy for survival for them both. It’s like an epic movie story line!
Xanthoria Parientina - Common Sunburst Lichen on Birch 2021.
So grab yourself a magnifying glass this week and look out for the incredible world of Lichens. I found all these ones really close to home. Lichens are such a great source of interest on our Forest School Sites, it’s always a pleasure to see them.
Take care and hope to see you all soon at W.I.L.D.
'Scottish Lichens' group on Facebook.
With Many Thanks