Where do lichens grow?
Lichen-dominated vegetation accounts for about 8 percent of land surface. They grow in almost all natural environments apart from the deep sea, and in a variety of different climatic conditions. They also grow in cities (e.g. churchyards) and, depending on pollution levels, many other environments created by humans. They play a very important ecological role as carbon fixers, and recyclers of the elements and nutrients, nitrogen, phosphorous and sulphur. They also assist in breaking down rocks. On rocky coasts, lichens form one of the classic examples of ecological zonation, with each level subject to different exposures to salt. The fact that lichens have adapted to these particular conditions can be seen in the variation of species and colours.
