Lichens are called pioneer colonizers of bare rock. How can they help in formation of soil?
Answer:
Organisms that can colonize bare rock are called pioneer species. Lichens are usually the first pioneer species, and they look like color splotches on the surface of rocks - white, green, grey, yellow or even orange.
Once lichens have been growing on rocks for a while, mosses are able to survive there too. Mosses are plants that don't have flowers or stems or roots - just tiny green leaf-like structures and microscopic hair-like structures. Mosses build habitat for small flowering plants; the flowering plants provide habitat and food for more creatures. Flowering plants have roots that hold the soil in place, and they also add to the soil as they die back each winter and decompose. Their decay and decomposition lead to increase in organic content of the soil which paves way for other forms of vegetation.