The Physiological And Ecological Impacts Of Urban Typical Afforestation Trees Polluted By Dust

The research of relationship between dust pollution and plant focused mainly on the effect of dust retention of plants or plant communities in urban,but the research of plant physiological ecology effects of the dust-covered plants were lack.In this article the physiological and biochemical indicators of changes and chlorophyll fluorescence parameters changes and its spatial and temporal changes of the dust-covered foliar were studied,the results could provide a more scientific basis for the city dust contamination control as well as the selection of the urban trees,and further enrich the content of environmental biology research.The main conclusions of this study can be summed up as follows:(1)Under the contaminated of dust,the physiological and biochemical of plant changed obviously, the photosynthetic efficiency was inhibited.The total chlorophyll content declined up to 37.5%,the chlorophyll a/b ratio was increased to varying degrees;the protein content declined up to 26.7%,proline,malondialdehyde,soluble sugar content and relative conductivity were generally higher than that non-dust-covered foliar(ɑ=0.05).The Fv/Fm and Fv′/Fm′both declined in varying degrees,the qN value of the dust-covered leaves increased about 95%~183%.(2)The plant of Xinzhuang and Central Gate interchanges significantly affected by dust pollution,the chlorophyll a/b ratio of Xinzhuang interchange had been increased by an average of 20.5% than the other contaminated areas,the proline content of Central Gate interchange increased by 60% over compared to other contaminated areas(ɑ=0.05).(3)The chlorophyll content of Robinia pseudoacacia L and Broussonetia papyrifera were consistent with variation,chlorophyll content generally declined in the increase of dust concentration,and then increased as the dust concentration increases further,chlorophyll a/b ratio was also reflected with the increase in dust pollution to increase,and then to reduce.The relative conductivity along with the dust concentration on the increase in the overall upward trend in the first,and then as the concentration of dust pollution showed a downward trend to further increase.The laws indicated that plant affected by the dust pollution could divide into two processes,first of all,dust pollution is a state of deterioration of plant physiology, and then the physiological indicators of plant was recoveried,indicating that the concentration of dust pollution reached a certain concentration and time would produce a stimulating response to meet the plant dust habitats.This resistance mechanism associated with the plant,pending further research and feasibility studies.(4)The chlorophyll fluorescence of Robinia pseudoacacia L showed that as the dust concentration increased,the qP value declined,the qN value increased,and Fv,Fm,Fv/Fo,Fv/Fm and Fv′/Fm′were equivalent with the increase in dust concentration,the first declined after the rise,which inspired response effect on the dust-covered foliar.