Distribution pattern and heavy metal accumulation in lichens of Bangalore city with special reference to Lalbagh garden

Abstract

Occurrence of 30 species of lichens belonging to 19 genera and 15 families in 12 localities of Bangalore city is reported. The Indian Institute of Science (IISc) campus and Lalbagh garden record the maximum number of 24 and 18 species of lichens respectively, which can be directly attributed to the presence of a variety of trees in the area providing diverse substrate for lichen growth. Heavy-metal accumulation in few prominent lichens of some localities is also analysed. Cr and Pb were maximum in Chrysothrix candelaris (L.) Laundon, at AMCO Batteries area with 95.29 and 623.95 μg g^-1 dry wt. respectively. Fe and Cu were maximum in Bulbothrix isidiza (Nyl.) Hale and Pyxine petricola Nyl. at IISc campus with 22721 and 338.12 μg g^-1 dry wt. respectively, while Lecanora perplexa Brodo at Lalbagh garden has 531.5 μg g^-1 dry wt. of Zn. The lichen flora of Lalbagh garden is compared to an earlier enumeration. It is interesting to note that in the last 18 years lichen flora of the area has changed significantly, as only four species were common between the two studies. The fast pace of urbanization together with air pollution may probably be the reason for the change in lichen flora of this area. The present number, type of lichen and the level of metals accumulated will be a record for conducting future biomonitoring studies in this fastest-growing city of India.