Analysis To The Ecological Factors Affected On The Forest Pest And Evaluation Of Forest Ecological Environment Quality Based On GIS

Dendrolimus spp. was one of the main pests in the HeBei province, they could weaken the growth of the pinus tabulaeformis Carr, affect forest ecological environment. So the harm extent of Dendrolimus tabulaeformis and D.spectabilis were investigated in the high altitude region , hill regions and plain region . In this paper , the relationship between the occurrence degree of pests and the ecological geography factors was analyzed; according to the application of geography information system in the research of plant pestsand its peculiar spatial analytical function, combining with the characteristics of the plant pests and related statistical methods, the application of the geography information system in the management of plant pests were further quested. Geographic information system and Analytical hierarchy process, which were applied in appraising foresty ecological environment quality , which can offer scientific reliable foundation basis for forest resource development and reasonab using.According to the multianalysis between the ecological factors and the harm extent of the pest, the model was set up, and the analytical result was very prominence. According to the line regression analysis and stepwise regression analysis, the main factor affected the harm extent of the Dendrolimus tabulaeformis and D.spectabilis was different in different regions, the main factors are altitude, crown-diameter and Crown density in luanping county, qianxi county were crown density , crown diameter and slope; qinglong county were Crown diameter and forest density; changli county were forest age , Crown height, the analytical result was very prominence, in a word ,the stand factors were more influential than geography factors.By overlay analysis,in different regions , the different ecological factors had different affecting extent in different regions,the result was that : in the areas of slope more than 25 ° ,crown-density more than 0.8, foresty density more than 2500 in each hectare, crown-diameter more than 2.5m and tress number more than 15, the pest is not easily outbreak; otherwise the pest is easily outbreak if the foresty is not health.The communities of insects and vegetation were investigated in the different regions, providing reference of evaluation of foresty ecological environment quality .the result was that : most of the insect'species and plant'species were almost the same, the main species of the insects were Lepidoptera and Coleoptera, the two items occupied more than 40 percent of all the insect community. The species of the insect were the highest in luanping county, the number is 34, the shan-wiener index of the insect community in qianxi county, which is 1.8724, the ratio of pest and natural enemy was the smallest(2.1836 : 1); we surveied 32 families 72 species of vegetation in the four regions, because the...