Previous Year Question

Lichens are not single organisms; they are mainly formed through a symbiotic association between a Fungus and an Alga or Cyanobacterium.

Unlike normal plants, lichens lack a well-developed root system and protective cuticle. They obtain water and many substances directly from their surrounding environment. Therefore, the effects of atmospheric pollutants become visible in them relatively quickly.

Lichens are particularly sensitive to air pollutants such as Sulphur Dioxide (SO₂). In highly polluted areas, the number and diversity of sensitive lichen species may decline.

Therefore, the presence, absence, abundance and diversity of lichens in an area can be used as a biological indication of air quality.

For this reason, Lichens are regarded as good Bio-indicators of air pollution.