广州市帽峰山常绿阔叶林生态系统对降水PAHs的生态效应

Polycyclic Aromatic Hydrocarbons in Rainfall in a Evergreen Broad-leaved Forest in Maofeng Mountain,Guangzhou

采用森林生态系统水循环定位观测及高效液相色谱法,对广州市帽峰山常绿阔叶林森林生态系统的降雨、穿透水、树干茎流、总径流、土壤渗透水水文过程中6种PAHs质量浓度进行了1a的定位测定,结果表明:大气降雨检出6种PAHs,其质量浓度在旱季明显大于湿季;林冠层、树干茎流对降水中的6种PAHs具有较强的吸贮效应;总径流中PAHs的质量浓度比降雨中有明显降低,反映出帽峰山常绿阔叶林生态系统进入系统水环境质量具有显著的储虑及降解净化效应;其中,土壤对水体PAHs的吸附含量随着土壤剖面的加深而减少,反映出森林土壤的化学储虑机制;土壤中有机碳含量是影响PAHs纵向迁移的重要因素。

The concentrations of 6 polycyclic aromatic hydrocarbons （PAHs） in precipitation, through-fall, stem-flow, runoff, and soil solution were measured by liquid chromatography in a monsoon evergreen broad-leaved forest in Maofeng Mountain in Guangzhou. Results showed that 6 kinds of PAHs were all detected in precipitation, and the concentrations of PAHs during the dry season were higher than those during the wet season. The crown layer and stem-flow had obvious functions on PAH storage. The concentrations of total PAHs in runoff were lower than those in precipitation, which indicates that the forest ecosystem has a strong ability for purifying PAHs. The concentrations of PAHs in soil declined with depth, indicating a filtration function of the forest ecosystem. Total organic concentration in soil plays a major role in the vertical distribution of PAHs.