Question

Do you know that lichens can be used as indicators of industrial pollution?

Answer 1

Lichens are symbiotic associations between fungi and algae. Algae through the process of photosynthesis provide food to the fungal component and the fungi provide a home for the algae. They do not have roots and absorb nutrients from the atmosphere.

Too much nitrogen in the atmosphere (in a polluted area) can kill the chlorophyll in the algae thus destroying the lichen. They are pH sensitive and thus if the rain is acidic they are killed. They are sensitive to the amount of sulphur dioxide in the atmosphere.