Lichen

At 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.