Effect Of Forest Spatial Structure On Damaging Degree Of Cephalcia Kunyushanica Xiao And Pine Needle Blight

Kunyu natural secondary Pinus densiflora forest is the world’s best preserved Akamatsu natural distribution center, it is the valuable "Jiaodong plant kingdom". Cephalcia kunyushanica Xiao and the pine needle blight are the major pest and disease in kunyu forest farm, they seriously damage to the stability of the kunyu mountain ecosystem, and have a huge impact on the healthy development of natural red pine forest. In this study, as the research object, Kunyu natural secondary Pinus densiflora forest has been set up6hectares sample plot in there. We select the mingling degree, neighborhood comparison and uniform angle index as the indicators of spatial structure, use the pest population density and disease incidence of as the indicators of pest and disease stuation. This research attempts to identify the relationship between the forests individual spatial structure of Kunyu natural secondary Pinus densiflora forest and the occurrence condition of Cephalcia kunyushanica Xiao and the pine needle blight. Then we can reveal the influence of individual forest spatial structure on the infection and damage degree of Cephalcia kunyushanica Xiao and the pine needle blight. We hope find the regulation and control mechanism and mode theory of forest individual spatial structure to pests and diseases, further improve and supplement the forest ecosystem ecological control technology. It can provide the basis for forest sustainable management. The main results are as follows:The ecological community was made up of Japanese red pine, saw tooth oak and the other16tree species, in which the most abundant species was Japanese red pine, followed by the saw tooth oak. Mainly based on weak and moderate mingling degree, the average mingling in the stand was0.44. The average neighborhood comparison was0.50with the distribution frequency of each part relatively even, which showed that the tree species of the tree layer were relatively stable. The average uniform angle index was0.54with reunion distribution in the horizontal pattern. The mingling degree of the broadleaved tree species was a little better than that of the coniferous species, while the breast diameter of the broadleaved tree species was much shorter than that of the coniferous species, which illustrated the broadleaved tree species were seriously oppressed by the coniferous species.The linear relationship between the spatial structure indicators of Pinus densiflora and Cephalcia kunyushanica Xiao is significant. Uniform angle index and population density is positively correlated (R2=0.828); the neighborhood comparison among diameter at breast height and tree height are negative correlate with population density (the R2=0.9138and R2=0.9116);The relation between mingling degree and population density is negative, but the population density is most when the mingling degree is highest. It prove that the stronger the degree of spatial segregation, the higher the possibility of a serious outbreak of pests. Cephalcia kunyushanica Xiao not only feeding Japanese red pine, but also feeding other pine species, but there is no significant correlation between the spatial structure of indicators and the population density in the rest species.The linear relationship between the spatial structure indicators of Pinus densiflora and the pine needle blight is significant. The Uniform angle index and mingling degree are negative correlation to disease incidence, but the correlations are not very significant. The neighborhood comparison among diameter at breast height and tree height are negative correlate with disease incidence (the R2=0.9635and R2=0.7807). The pine needle blight is wider infection, there is a significant correlation between the spatial structure and disease incidence in other pine species.