The Effects Of Subtropical Woody Plants Under UV-B Radiation Stress Or Acid Rain Force

The effects of subtropical woody plants under UV-B radiation stress or acid rain force aredisscused in this paper on the aspects of growth, the chlorophyll content, photosynthetic physiology andso on.In order to aboud the studies about woody plants under UV-B radiation stress and different types ofacid rain force,we selected typical subtropical woody plants which are Carya cathayensis、Myricarubra、 Cinnamomum camphora、Schima superba and Cyclobalanopsis glauca as experimentalmaterials.The result showed that:1. It produced positive or negative impacts to the trees while incresing or reducing the UV-Bradiation.2. Weakened radiation could keep the chlorophyll of leaves safely at a higher level than that in thecondition of strong radiation.3. It’s bad to the photosynthesis of trees whether incresing or reducing the UV-B radiation.4. The gas conductance and transpiration rate of Carya cathayensis and Cinnamomum camphorareduced under the strong UV-B radiation stress while Myrica rubra incesed. The water use efficiency ofMyrica rubra leaves was lower under strong UV-B radiation stress,but it promoted the WUE ofCinnamomum camphora.5. The water physiological parameters of trees were not significant related to the chlorophyllcontents,but they were significant related to the photosynthetic physiology of plants.6. The growth of trees were inhibited under the low concentration of acid rain force.It’s worse togrow under nitric acid rain force or mixed acid rain force.7. Sulfuric acid rain and nitric acid rain are the worst to the chlorophyll contents of trees. Nitricacid rain and mixed acid rain were both bad to the chlorophyll contents of Cinnamomum camphora.8. The water physiological parameters of plants reduced because of the low concentration of acidrain.And the low concentration of acid rain also affected the photosynthetic physiology of trees. Nitricacid rain and mixed acid rain were great impact to the photosynthetic physiology of trees and theyreduced Gs and Tr of plants,too.