Question

Lichens can be used as

• A. Bio-indicator for water and air pollution
• B. Initial vegetation for waste lands.
• C. Source of wood
• D. To check the air pollution

Answer 1

The correct option is A Bio-indicator for water and air pollution

Lichens are mutualistic associations of a fungus and an alga or cyanobacterium. Lichens are very sensitive to sulphur dioxide pollution in the air. Lichens are sensitive to sulphur dioxide because their efficient absorption systems result in rapid accumulation of sulphur when exposed to high levels of sulphur dioxide pollution. The algal partner are most affected by the sulphur dioxide; chlorophyll is destroyed and photosynthesis is inhibited. 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. If the air is clean, shrubby, hairy and leafy lichens become abundant.