关键词: 景天酸代谢植物(CAM植物), 糖代谢, 八宝景天, CO₂浓度, 光合作用

Abstract: By using GC/MS method, this paper analyzed the vertical profiles of 16 priority polycyclic aromatic hydrocarbons (PAHs) proposed by US EPA in a sediment core collected from the Hongfeng Lake in Southwest China. Meanwhile, the composition characteristics of the PAHs, their possible sources, and their ecological risks were discussed. The total PAHs concentrations in the sediment core ranged from 848 to 3725 ng·g^-1, with a peak in the mid-1990s. The vertical profiles of the PAHs were not only different from those in developed countries, but also different from those in the coastline and other regions lakes in China. The PAHs in Hongfeng Lake were mainly come from the low temperature combustion of domestic coal and biomass burning. However, the relative abundance of the PAHs from high temperature combustion processes, such as the combustion of industrial coal and vehicle emission, was increased significantly in recent years. The risk assessment suggested that the low rings PAHs such as NAP, FLU, and PHEN in the sediment of Hongfeng Lake could induce potential ecological risks. However, from the viewpoint of toxic equivalency quotient, the ecological risks were mainly originated from the high rings PAHs such as BbF, BaP, and DBA.

Key words: Hylotelephium erythrostictum, CO₂ concentration, crassulacean acid metabolism plant (CAM plant), photosynthesis, carbohydrate metabolites.