| Abstract: | Ring characteristics of pine trees grown in polluted air showed up distinctly as a decrease in newly devised synthetic indicators such as product of W (relative ring width) and DD (relative difference between maximum and minimum density within a ring) or product of W and MD (relative mean density). Intensity of combined air pollution was estimated by the total of daily maximum concentration of SO2, ozone, NO2, and NO2. Since synthetic indicators show a significant correlation, at the over 98% confidence level, with the intensity of combined air pollution, phytotoxicity of air to pine growth must be attributable at least in part to combined effect of air pollutants. |
