What are lichens?
Lichens are a symbiotic composite life form. A fungi and either an algae or cyanobacteria lving together. The algae lives inside the fungus and photosynthesize sunlight into food for both the fungus and algae. The fungus for it’s part provides a safe environment for the algae to live. It absorbes water and minerals from the environment for them both.
They are slow growing and considered some of the oldest life forms living on the planet. They grow everywhere from rock faces to tree branches to man made structures like concrete.
Lichen as an indication of air quality
Lichen are often reguarded as a good indicator of air quality in an area. Many species of lichen are very susceptible to pollution and the mix of lichens in an area can indicate air quality. Sulphur dioxide is one of the main pollutants that affect lichen. It is mainly produced by burning fossil fuels such as coal fired power stations.
In area with low pollution levels the hairy / leafy lichen types (fruticose) are present. In high pollution levels only crust like lichens (crustose) attached tightly to the surface are present. If any lichens are present at all.
Lichens in our orchard in Llanblethian
There is a varied range of lichens present in Llanblethian orchard. They indicate the great air quality. They are also proof we don’t spray our trees with fungicides. In modern intensive’ orchards the bark is perfectly clean. This is due to all the chemicals used. Killing the lichen.
Lichen provide valuable nesting material for birds as well as shelter for several beneficial insect species.
Below are some images of the lichens growing on our trees. It’s wonderful seeing so many different species present. It does’nt half make spotting canker in the canopy difficult mind!