Assessment of the Influence of the Tolerance and Purification Ability of Sidewalk Trees to Sulfur Dioxide After Long-Term Fumigation

摘要

This study utilized a custom-made fumigation chamber to evaluate the tolerance and purifying efficiency of 10 species of common trees with 40 ppb SO_2 for 120 days. Results showed that the growth and condition of tested tree species, Cerbera manghas, Decussocarpus nagi, Diospyros maritima, Erythrina variegata, Ficus septica, Melia azedarach and Messerschmidia argentea, in SO_2 polluted environment were affected. The 40 ppb SO_2 polluted environment promoted growth in Diospyros morrisiana and Machilus zuihoensis trees. Among all tested tree species, Diospyros discolor had the highest tolerance while exposed with 40 ppb SO_2. Melia azedarach had the least tolerance. However, the purifying efficiency in relation to SO_2, Messerschmidia argentea had the greatest capacity, and Delonix regia had the lowest. The combined rankings of tolerance and purification of tested trees to SO_2 showed that Messerschmidia argentea was the best choice of side walk tree species and Erythrina variegata was the weakest.