Biocriteria Demonstrating of Air Pollution Stress on the Plane-tree (Platanus orientalis L.)

Increasing energy demands associated with economic growth and industrialization have resulted in dramatic increases in air pollution emissions. Air pollution damages the plant mainly by disrupting cell homeostatic conditions. In the present study، diverse plant criteria indicating air pollution from different levels including cell biochemistry، leaf and tree crown in the plane-tree were determined، and their relation to the air pollutants such as ozone، nitrous oxide، nitrogen dioxide، sulfur dioxide، carbon dioxide and particulates was investigated. Results showed that the concentration of Chlorophyll a and chlorophyll b in the leaf of plane-tree are reduced with increase in the ozone concentration in the air. The concentration of Chlorophyll a and chlorophyll b are negatively correlated with NO in the autumn (r= -0. 69 and -0. 72، respectively). Specific leaf area showed a positive relation with the concentration of ozone، nitrogen dioxide and carbon monoxide (p<0. 05). Crown transparency did not show any relation with air pollutants. On the contrary، crown area ratio was positively correlated with NO2 in the summer (p<0. 05). Specific leaf area was a good indicator of air pollution stress and damage to sycamore especially in the spring. Moreover، crown area ratio responded better than crown transparency to air pollutants and can be a suitable indicator of NO2 effect on the plane-tree. This criterion has a large potential as an indicator of various stresses on the tree due to its fast and easy measurement by a consumer-grade digital camera and available image processing software.