Question

how to lichens act as pollution indicators​

Answer 1

Answer:

Lichens also absorb sulphur dioxide dissolved in water. Lichens are widely used as environmental indicators or bio-indicators. If air is very badly polluted with sulphur dioxide there may be no lichens present, just green algae may be found. If the air is clean, shrubby, hairy and leafy lichens become abundant.

$\sf\huge\bold\ ⠀ ⠀ ⠀ {⚠risk}$

Answer 2

Answer:

Air pollutants dissolved in rainwater, especially sulphur dioxide, can damage lichens and prevent them from growing. This makes lichens natural indicators of air pollution. ... Leafy lichens can survive a small amount of air pollution. Crusty lichens can survive in more polluted air.

hope it helps u