1. Formation of fissures in mountain ranges: Crustose lichens grow on rocks in deserts and mountain ranges. Crustose lichens cause fine cracks in the ridges. It breaks the big stones into small stones.
2. Wounding of rock formations: Oxalic acid and carbonic acid released from lichens cause wounding of mountain rock formations. This reduces the durability of the stone and makes it brittle.
3. Disintegrating rocks: Carbon dioxide produced by lichen respiration combines with rainwater to form carbonic acid. Carbonic acid disintegrates stone. Turns into small stones.
4. Soil formation: Lichen corpses accumulate to form humus. Humus degrades the quality of rock and mixes with rock to form soil. The process of soil formation is called pedogenesis.
5. Creation of fertile soil: Dead bodies of foliose lichens, fruticose lichens, mosses, ferns etc. mix with the soil to create fertile soil. A variety of crops and forest plants grow on fertile soils.
Pedogenesis of lichens is a chronically slow process. It is a natural method and the result of many years.

1. Soil formation from rocks: CO2 released from lichens mixes with rainwater to produce carbonic acid. Carbonic acid corrodes the rock into small particles. The particles mix with the dead bodies of lichens to form soil.
2. Increase in water holding capacity of soil: Dead bodies of lichens form humus in soil. Humus increases soil water holding capacity and increases fertility.
3. Environmental purification: Lichens take in CO2 and release O2 in the process of photosynthesis. As a result, the atmosphere is pure.
4. Adsorption of Pollutants: Lichens require clean air free from pollutants to grow. They cannot tolerate air pollution. So lichens absorb carbon dioxide, heavy metals and other pollutants from the air.
5. Nitrogen Fixation: Lichen forming cyanobacteria (Nostoc, Anabaena) take free nitrogen from air and convert it into NH3, NO3 etc.
6. Environmental indicator: Lichen acts as an indicator of environmental pollution. If lichen grows in a polluted area, it can be understood that air pollution is decreasing in that area.
7. Enhancing the beauty of the environment: Lichens grow on exposed hills and tree barks making them beautiful. As a result, the beauty of the environment increases.
8. Primary succession: Lichens play a major role as primary succession in creating forests on rocky or rocky sites. They form the first step in plant succession, initiating the formation of forests.
9. Oxygen release: Lichens release oxygen into the environment in the process of photosynthesis.
10. Ecosystem dynamics: Components of lichen ecosystems. Animals depend on lichens. Hence lichens help in ecosystem dynamics.
11. Destructive action: Lichen growth causes decay in wood, trunks, walls, roofs, etc.

1. Eating poisonous lichen (Parmelia molliuscula) kills humans and other animals.
2. It grows and damages walls and buildings.
3. They damage marble stone buildings and monuments.
4. Lichens called Usnea and Evernia cause skin diseases, allergies, asthma etc. in humans.
5. Damages the durability and beauty of windows and doors and wood.
6. Damages host plants like Cladonia, Amphiloma, Usnea etc.
7. Usnea lichens help spread wildfires from one tree to another.
8. Letharia vulpina lichen contains toxic substances and is used to kill wolves.

Lichens act as environmental pollution indicators. If lichen grows in a polluted area, it can be understood that air pollution is decreasing in that area.

Evernia prunastri and Pseudevernia furfuracea yield naphthalene, camphor, geraniol and bornel. Soaps, perfumes and other cosmetics are made with these ingredients.

Lichen contains more than 550 natural constituents. Lichens, zeorin, calycin, phycion, xanthomus, terpenoids, benzyl starch, usonic acid, rhizocarpic acid, salagenic acid (Ramalina fraxinea), lecanric acid (Parmelia saxatilis), squamatic acid (Cladonia rangiferina), arsenic acid, zeorin etc. goes

Tannins are obtained from Cetraria islandica and Lobaria pulmonaria which are used in leather tanning.

Litmus paper is prepared from lichens called Rocella montaignei and Lasallia papulosa.

Valuable blues called archil and cadbear are made from lichens. Archil and orsine prepared from Rocella tinctoria are used to stain microscopic objects. Red and purple dyes are made from Ochrolechia androgyna and Ochrolechia tartaria. It is used to dye woolen and silk fabrics.

Caloplaca saxicola, Circinaria calcaea, Begonia lichenora, Aspicilia cinerea etc. are used as food for ants, caterpillars and snails.