Impacts Of Bursaphelenchus Xylophilus Invasion On Pinus Thunbergiana Community In Jiaxing Area, Zhejiang Province

Bursaphelenchus xylophilus as one kind of invasive species is destructive to forestry in China. This thesis analyzes the the invasion of Bursaphelenchus xylophilus having effects on the diversity of flora and the P.thunbergii with various degrees of destruction having effects on the Bursaphelenchus xylophilus invasion based on the 17 blocks of heisonglin with different type and grades of destruction in Pinghu, region Jiaxing Zhejiang province. And the paper analyzes the resistance of the P.thunbergii under different circumstance. Through research, the main results are:1. In the aspect of diversity of foliage, different types of P.thunbergii with different destructive degree have a remarkable difference. The diversity of mixed P.thunbergii and broad-leaf forest is higher than pure pine forest. The index of plant diversity has a different change because of the various degree of damage as the P.thunbergii is invaded by Bursaphelenchus xylophilus. The change of the three-layer species diversity index, as the fact is that Bursaphelenchus xylophilus directly influences the P.thunbergii on arbor, further influences the diversity index of arbor. While the change of the shrub's and the herbage's diversity index is after the change of arbor's, that is, the destructive degree indirectly effects the shrub's and the herbage's diversity index. The diversity index of arbor increases with the destructive degree, while the shrub's diversity index is on the contrary and the herbage'is following the degree.2. From the view of community structure, put a small plot (5m×5m) test on the different standard plant space distribution, using theory and structure density determinant. The congregated intensity adopts the diffusion coefficient, negative...