Lichen dyes are still used by some craft weavers who like their soft, quiet colors. Today, the only commercially important lichen dye is used to make litmus paper, to test the acidity of liquids. Lichens can be an important food source in extreme environments. The Lapp people, who live above the Arctic Circle in Scandinavia and Russia, harvest lichens as winter food for their reindeer, just like farmers in temperate zones stockpile hay. Sheep in the deserts of Libya survive, in part, by eating crustose lichens growing on rocks.
Lichens are also important in making soil.
Soil is made up of organic matter, such as decayed plants, and minerals. Species that grow on rocks infiltrate and wedge apart pieces of the rock by both pressure and chemical action. Some of their acidic secondary products dissolve the rock's surface, freeing mineral grains. This is an extremely slow process, but the resilience and endurance of the lichen fungi puts time on their side. Natural dyes and home dyeing.