What is the significance of lichens in nature and in human life?

Lichens play a huge role in nature in general.
These are the first organisms (“pioneers”), which colonizing the earth, can destroy rocks, forming soil for other plants. They are bioindicators of air purity. Participate in the geological cycle and soil formation. This is food, habitat and shelter of animals, nesting of birds.
In human life, lichens are used for food (for example, lichen manna).
Thanks to them, you can find out the age of a breed or building, since these organisms grow for a long time at a constant rate. They are also used in the perfumery, pharmaceutical industry and traditional medicine.