I have always been fascinated by lichens and their ability to act as barometers of air pollution and environmental health. They are particularly sensitive to airborne pollutants especially sulphur dioxide, nitrogen and ammonia, so if you see some lichen growing well, it’s usually a positive sign. I was very excited recently as I was able to examine a couple of lichens using a scanning electron microscope at University of Central Lancashire – here are a few of the photographs I took.
Lichens are incredible plants with an unusual chemistry – they are actually a fungus symbiotically existing with algae. The partnership is so close we consider it a single plant. They provide shelter and/or food for a wide variety of invertebrates – mites, molluscs, spider and moths. Many birds use the plant as camouflage for their nests.
It’s hard to date the origin of lichens, being composed of soft tissue and therefore unlikely to be found in fossils, however earliest examples date back 600 million years ago in China.
Worldwide there are about 18,000 species.
The two images are of the inside of a single cone of Cladonia fimbriata – wonderful!