Assessment of air pollution tolerance index of some trees in Haridwar City, Uttarakhand

Three different plant species i.e., Ficus religiose, Polyalthia longifolia andAzadirachta indica were collected from residential (S1), commercial (S2), industrial (S3) and control areas of the city to study the relative tolerance of plant species. Variation in biochemical parameters like relative water content, leaf pH, ascorbic acid, total chlorophyll, carotenoids and dust interception efficiency were found to be pollution load dependent. These variations can be used as indicators of air pollution for early diagnosis of stress or as a marker for physiological damage to trees prior to the onset of visible injury symptoms. The present findings showed that maximum APTI was observed in Azadirachta indica and minimum in Ficus religiose.