The Main Forest Diseases And Insect Pests Of And Their Response To Urban Air Pollution In Yan’an City

In this paper, Yan’an City was studied, through the study of diseases and insect pests of forest in Yan’an City and response of the urban environmental pollution, in order to provide new ideas and new methods to disease control and prevention in Yan’an City, so as to provide basis for the achieved results of urban ecological construction in Yan’an. In this study, a sample survey and a comprehensive survey were investigated and study the diseases and pests of Yanan urban area(different polluted areas), and the following conclusions were obtained:(1) There were 20 kinds of the main harmful forest diseases and pests in Yan’an City, and four kinds of diseases and sixteen kinds of pest. In 20 kinds of diseases and insect pests, it’s the first time that Aphrophora costalis Matsumura, Prociphilus ligustrifoliae(Tseng et Tao).Aphis gossypii Glover were found in Yan’an City. And Aphrophora costalis Matsumura and Prociphilus ligustrifoliae(Tseng et Tao) were the most severities damage, and the occurrence range was wide.(2) In Yan’an City, the analysis of spatial pattern of plant diseases and insect pests showed that, the most kinds of diseases and insect pests is Qiao Gou and jujube orchard, the fewest township of plant diseases and insect pests was He Zhuangping, and the harm degree of plant diseases and insect pests was the most serious inKawaguchi and Yao Dian. According to the spatial distribution of diseases and insect pests, it’s known that the occurrence of plant diseases and insect pests was regional, and it’s mainly determined by the plant species in different towns. There was the occurrence of Platycladus orientalis leaf blight and canker of poplar, Dendroctonus valens, of cyamophilawillieti, Liu tip in spittlebug in many township.(3) In our study, we found that the more serious pollution of the area, more kinds of the plant and insect pests diseases; For the different polluted sites of disease and insect damage type, we make a statistics, and the result was that kinds of diseases and insect pests in polluted area were significant higher than those in the unpolluted area, and the pollution to plant diseases and insect pests have stimulative effect, plant diseases and insect pests occurrence is the result of Comprehensive function inpollution, host plant species and quantity.(4) The order of occurrence, propagation and damage of the same kind of diseases and pests in different polluted areas is: severe pollution area > moderately polluted area > slightly polluted area>control area. With the increasing degree of pollution, the range and the harm degree of Aphrophora costalis mats and poplar rot disease were more serious. It showed that the same species of pests and diseases in different pollution areas, the degree has a great relationship with pollution.(5) In Yan’an City, the prevention method of pest damage is relatively simple, it’s all the artificial prevention and control, and prevention and control measures was relatively backward,for pest damage occurrence and control status in Yan’an City, we proposed biological control and improve the quality of environment improvement were the main method, and thephysical and chemical control were supplemented.