What is the role of lichens in nature?

Lichens play a large role in nature.
Their role is especially great in tundra, forest-tundra and forest communities, where they make up a noticeable part of the vegetation cover.
A large group of animals is associated with lichens. These are mainly invertebrates, but there are also large vertebrates, such as reindeer, for which lichens serve as the main food in winter.
A huge number of ticks, caterpillars, springtails, spiders, etc. live in lichen thickets. Some animals use lichens as a temporary refuge, others feed on their thalli and products of destruction. Breaking off the branches of thallus, animals contribute to the vegetative reproduction of lichens.