Effects Of Simulated Acid Rain On Chlorophyll Fluorescence Characteristics Of 12 Species Of Evergreen Broad-leaved Seedlings

With the worsening of acid rain pollution, acid rain on plant especially the impact of forest vegetation have also become more severe. Many scholars has done a lot of research from the areas of plant physiological ecology of the harms caused by acid rain, and achieved remarkable results. However, long-term of acid rain affected chlorophyll fluorescence characteristics of trees is very few reports.The experiment set four groups of simulated acid rain treatments, including pH2.5,pH3.5,pH4.5 and pH5.6 (CK) in high acid rain area in Lin'an,through 18th months of simulated acid rain treatment to 12 kinds such as Eleocarpus glabripetalus,Schima superba,Ilex integra,Auingia chinensis, Castanopsis sclerophylla, Castanopsis eyrei, Lithocarpus glaber, Cyclobalanopsis glauca, Cyclobalanopsis gracilis, Cinnamomum camphora, Machilus pauhoi,Lindera megaphylla broad-leaved evergreen Health potted seedlings for the test material was used to study the effects of simulated acid rain stress on chlorophyll fluorescence Parameters,chlorophyll content and growth.The results showed that:(1)Use chlorophyll fluorescence as a natural probes to study and detection of simulated acid rain on the growth of plant seedlings is feasible,chlorophyll fluorescence parameters(Fv/Fm,Fv/Fo,ΦPSII)and Relative chlorophyll content( SPADR)can be as important indicators of the impact of acid rain.ETR and other chlorophyll fluorescence parameters have the same changes in basically, but its excessive dependence on light intensity values, it is not as impact indicators.(2)Study found that the height and diameter have the general trend of changes in the same with chlorophyll fluorescence parameters (Fv/Fm,Fv/Fo,ΦPSII, ETR) and the relative content of chlorophyll (SPADR), intuitive reaction to 12 kinds of evergreen broad-leaved tree seedlings on the effects of simulated acid rain Response.(3)Simulated acid rain on 12 kinds of evergreen broad-leaved tree seedlings have had a certain impact, notable differences in summer and winter particularly.In the long term under the influence of simulated acid rain, hurt by the stress of simulated acid rain tree seedlings more vulnerable to high temperature, high light intensity and low temperature impact.(4)Study found that changes in the three modes response to acid rain of A>B>C.Class A species including Eleocarpus glabripetalus.Class B including Schima superba,Ilex integra,Auingia chinensis,Castanopsis sclerophylla,Castanopsis eyrei,Cyclobalanopsis gracilis,Cinnamomum camphora. Class C including Lithocarpus glabe,Cycloba- lanopsis glauca,Machilus pauhoi,Lindera megaphylla.The injury threshold values of class A,class B are observed at the treatments between pH3.5 and pH2.5 in this experiment,class C is appear in treatments between pH4.5 and pH3.5.At present the natural acid rain only on the Class C species can cause some stress injury, while the other three categories role of promoting.