Visual and Physiological Characteristic Changes of Five Tree Species Exposed to SO_2

摘要

After long exposure to low-density SO_2, the five tree species showed different changes in their visible damage: Ailanthus altissima showed no visible damage; Acanthopanax sessiliflorus, Populus alba XPopulus glandulosa, and Platamts orientalis showedtypical damage of yellow spots on their leaves; and Liriodendron tulipifera showed serious damage on the end of leaf tip. The photosynthesis rate of Liriodendron tulipifera and Acanthopanax sessiliflorus was usually lower than the control group: Ailanthus altissima, Populus alba XPopulus glandulosa, and Platanus orientalis showed no difference from the control group, while Acanthopanax sessiliflorus and Liriodendron tulipifera showed large changes. In regard to the light compensation points, Ailanthusaltissima showed similar values, Populus albaX Populus glandulosa and Platanus orientalis exposed to SO_2, showed 3 to 5 umol m~(-2)) s~(-1) higher values than the control group, and Acanthopanax sessiliflorus and Liriodendron tulipifera exposed to SO_2showed approximately twice higher light compensation points.