Lichens: The Natural Bio-Indicator of Air Pollution

Ajay Kumar Gautam

Department of Botany,
 Abhilashi Institute of Life Sciences,
Mandi-175008 (H.P.) India.
Email: a2gautam2006@gmail.com

Lichen, a unique symbiotic association between an alga and a fungus, where algal component is called phycobiont or photobiont while fungus as mycobiont. These are the composite organisms which have an ability to colonize on a variety of substrates including rock, soil, trees and man–made structures in diverse environmental conditions. They occur in all possible environmental habitats of the world, but are diverse in tropical region and luxuriant in temperate-alpine areas. These along with mosses form dominant organism in ecosystem covering over 10 % of the earth's terrestrial habitat (Nash and Egan 1988; Hawksworth 2001).