Physiological Studies on the Leaves of some Avenue Trees, Exposed to Chronic Low Levels of Air Pollutants

The leaves of Eucalyptus longifolia and Peltaphorum ferrugrntum. Two very commonly found avenue trees in IPCL (Indian Petro Chemical Ltd.) township and Bauizinia lomentoso, a less distributed species were studied to evaluate the injury done by chronic low levels of pollution. All the three species retained less number of leaves per twig. E. longifolia and P. ferrugineun could maintain photosynthetic leaf area and leaf dry matter accumulated per leaf equal to the control. Under pollution stress leaf starch levels Were low but they maintained high levels of sugars. The more prevalent species E. longifolia and P. ferrugineum incorporated only about 30 per cent more sulphur in their leaf system. Whereas B. tomenlasa had 70 per cent incorroration. The incorporated sulphur probably transferred into other sulpher containing compounds like glulathionc and not in aminoacids. Pollution stress brought about a decrease in leaf protein, DNA. Ascorbic acid levels. Eucalyptus accumulates phenols.