least three kinds of lichen on a seaside rock in Co Donegal, Ireland.
Lichens doinate about 8% of the earth's surface. There are about 30,000
species known in the world and between five and ten new lichens are
discovered in the UK each year. They are important to people because
they are part of the nitrogen, phosphorus and sulphur cycles and they
are also vital in the early stages of soil formation.