Abstract
Pine wood nematode (PWN, Bursaphelenchus xylophilus), originating from North America, causes destructive pine wilt disease. Different pine forest ecosystems have different resistances to B. xylophilus,and after its invasion, the resilience and restoration direction of different ecosystems also varies. In this study, an interpretative structural model was applied for analyzing the response of pine forest ecosystem to PWN disturbance. The result showed that a five-degree multi-stage hierarchical system affected the response of the pine forest ecosystem to PWN disturbance, in which direct affecting factors are resistance and resilience. Furthermore,the analysis to the 2nd, 3rd and 4th degree factors showed that not only does distribution pattern of plant species and pine's ecological features affect the resistance of pine forests' ecosystem, but removal of attacked trees and other measures also influence the resistance through indirectly affecting the damage degree of Monochamus alternatus and distribution pattern of plant species. As for resilience,it is influenced directly by soil factors, hydrology,surrounding species provenance and biological character-istics of the second and jointly dominant species, and the climate factors can also have a direct or indirect effect on it by affecting the above factors. Among the fifth elements,the elevation, gradient and slope direction, topographical factors, diversity of geographical location and improve-ment of prevention technology all influence the response of pine forest ecosystem to PWN disturbance.
基金项目
国家重点基础研究发展规划(973计划)(2009CBl19200)
Program for Changjiang Scholars and Innovative Research Team in Universities(IRT0607)
China Invasive Alien Species and Its Security Review Program(2006FY111000)
cofounding program of scientific research base of Beijing Municipal Commission of Education()