Evaluation of air pollution tolerance index of tree species of Bikaner city (Rajasthan)

Abstract

The air pollution tolerance index (APTI) is one of the modern tools for assessing the impacts of air pollutants on plant physiology. The value of APTI is different for different plant species. Plants with higher values of APTI are tolerant and act as a sink due to their bioaccumulation ability for air pollutants. Hence, they can be planted to establish green belts in areas with severe air pollution, especially in industrial zones. The present investigation was carried out to assess the APTI values of top twenty urban tree species of the Bikaner city of North-Western Rajasthan. The leaf samples were taken from selected roadside trees distributed in the residential, commercial and industrial zones of the city. On the basis of APTI values, it was observed that Leucaena leucocephala (23.41), Eucalyptus camaldulensis (21.87) and Cassia siamea (21.39) had an APTI value above 20 and they are therefore classified as tolerant species. Similarly, Pongamia pinnata (9.48) showed APTI under 10, therefore it falls into the sensitive category. 80 % of the total species in the studied area are categorized as a moderately sensitive category. There were no plant species in very sensitive (APTI 30) category.

Keywords

• air pollution tolerance index (apti)
• bio-indicator species
• tolerant species
• roadside trees
• green belts