重庆南山大气SO_2污染与马尾松衰亡的关系

ATMOSPHERIC SO_2 POLLUTION AND DECLINE OF MASSON PINE(PINUS MSSONIANA)FOREST IN NANSHAN, CHONGQING

本文运用开顶式熏气装置研究重庆南山大气SO_2污染与马尾松衰亡的关系。通过SO_2模拟熏气试验确定了SO_2对马尾松急性和慢性伤害阈值和可见伤害症状,长期定点SO_2浓度监测结果表明南山马尾松衰亡区的大气SO_2改度超过了马尾松的慢性伤害阈值。SO_2浓度与马尾松衰亡程度的空间分布一致、衰亡中的马尾松针叶上出现的可见症状与SO_2熏气实验中所出现的症状相似。现场空气过滤实验证明SO_2污染是马尾松针叶受害的原因。

The relationship between the atmospheric SO2 pollution and the decline of the masson pine forest located in Nanshan on the south bank of Yangtze River near Chongqing was studied. This work included SO2 pollution monitoring, SO2 fumigation, filtered air experiment in situ,and analysis of sulfur content in needles. The results of air monitoring indicated that the SO2 pollution in this area was heavy, and the SO2 concentration in air was 0.35 mg/m3 averagely, with maximum 1.30mg/m3. The fumigation tests showed that masson pine was rather sensitive to SO2. The threshold dose of SO2 to mosson pine was about 0.66mg/m3 × 180 hours.The distribution of ambient SO2 in Nashan was coincided with the degree of the masson pine decline. The sulfur content of needles in the heavy SO2-pollution area was much higher than the control in the clean area. The masson pine saplings growing in the air-filtered chamber were more vigorous, and lower sulfur content than the control. The saplings growing in situ showed obviously decline symptoms such as wilting, necrosis sptos and anormal needles abscission. It was concluded from all of the results that the heavy SO2 pollution in Nanshan should be one of the main reasons for the decline of the masson pine forest.