The Characteristics of Needle Blight of Pure Pinus densiflora Forests in Kunyushan Mountains and Its Relationship with Forest Factors

【Objective】 The purpose of this paper was to analyze and evaluate the effect of forest factors on the occurrence of pine needle blight（DI and DSI） quantitatively, thus to provide theoretical guidance for the forest management and prevention of the pine needle blight in pure forests of Kunyushan Mountains.【Method】Pinus densiflora pure forests with relatively consistent forest age（about 34 a） were targeted as the research object in Kunyushan Mountains. Six forest indexes, including forest density, canopy cover, tree height, height under branch, diameter at breast height（DBH） and crown cover, as well as the disease incidence（DI） and disease severity index（DSI） of the pine needle blight were investigated. Variance analysis, correlation analysis and multiple comparisons were used to analyze the relationship between forest factors and pine needle blight. The key factors affecting the occurrence of needle blight were obtained by redundancy analysis.【Result】Pine needle blight was prevalent in P. densiflora forests, w