Abstract:

This study investigated the categories and concentrations of PAHs in the plants and soil of a Cinnamomum camphora stand at the suburb of Zhuzhou City, Hunan Province, using GC instrument. The concentrations of PAHs in different organs of overstorey trees in the C. camphora stand could be ranked in the following order: bark (8 641 μg·kg^-1) >fruit (7 520 μg·kg^-1) >root (7 115 μg·kg ^-1) >branch (5 352 μg·kg^-1) >leaf (4 481 μg·g^-1) >stem (2 843 μg·g^-1). In the whole C. camphora stand, the concentration of PAHs was 9 235 μg·kg^-1 for litter, 5 995 μg·kg^-1for overstorey trees, 3 631 μg·kg^-1 for understorey herbal plants, 1 466 μg·kg^-1 for soil and 245 μg·kg ^-1 for understorey shrubs plants. The PAHs concentration in the soil of the C. camphora stand decreased by over 50 in contrast to that in the soil of a bare land. At the same time, the PAHs concentration in the throughfall and surface runoff was lower than that in the precipitation due to absorption and degradation of the C. camphora stand. The results that C. camphora stand had the functions of absorption and degradation of PAHs could provide a scientific basis for urban forest construction and environmental protection.

Key words: Cinnamomum camphora stand, PAHs concentration, Understorey plants, Soil