大气悬浮颗粒物污染对厦门市行道树芒果光合生理指标的影响

随着城市的迅速发展，大气中总悬浮颗粒物(TSP)污染日益严重. 城市植被在吸附和净化TSP的同时，其正常生理生态过程也受到了深刻的影响. 2009年4、5月，对厦门市汀溪清洁对照区、厦大文教区、仙岳商贸区和海沧工业区大气TSP浓度及研究区内行道树芒果(Mangifera indica)的光合生理参数进行监测. 结果表明：汀溪、厦大、仙岳和海沧的日均大气TSP浓度分别为0.061、0.113、0.120和0.205 mg·m^-3；不同功能区行道树芒果受到的胁迫作用为工业区>商贸区>文教区>清洁对照区. 大气TSP污染导致芒果叶片的净光合速率、气孔导度和蒸腾速率显著下降，相关系数均在0.98以上，同时也是胞间CO₂浓度发生变化的重要因素；高浓度的TSP污染通过限制气孔导致芒果的光合强度显著降低.

Impact of atmospheric total suspended particulate pollution on photosynthetic parameters of street mango trees in Xiamen City

With the development of urbanization, total suspended particulate (TSP) pollution is getting serious, and the normal physiological processes of urban vegetation are profoundly affected while adsorbing and purifying the particulates. In this study, four areas were selected, i.e., Tingxi reservoir (clean control area), Xiamen University (cultural and educational area), Xianyue (business area), and Haicang (industrial area), with their atmospheric TSP concentrations and the photosynthetic parameters of street Mango (Mangifera indica) trees monitored in April and May, 2009. The daily average concentration of TSP in Tingxi, Xiamen University, Xianyue, and Haicang was 0.061, 0.113, 0.120 and 0.205 mg·m^-3, respectively, and the impact of TSP stress on M. indica was in the sequence of Haicang > Xianyue > Xiamen University > Tingxi. TSP pollution negatively affected the net photosynthetic rate, stomatal conductance, and transpiration rate of M. indica, and induced intercellular CO₂ concentration changed significantly. High TSP concentration could cause the decline of net photosynthetic rate via stomatal limitation.