Study On The Environmental Impact Eco-assessment And Management Of Pine Wood Nematode In Zhejiang Province

Bursaphelenchus xenophiles, a destructive invasive alien forest pest in China, has had a devastating effect on sustainable forest development and ecological safety. Pine wood nematode(PWN) has cost over 100 billion RMB directly and indirectly since it was found in Nanjing 1982. The invasion of PWN, which occurred in 1991, has spread to over 340,0000 hm2, damaged more than 33 million pine trees, reduced 3,400hm2 woodlands to badlands and decreased the export of forest product from Zhejiang Province. Until 2005, Zhejiang was the most effected and damaged province. PWN is a serious threat to the economic development of and ecological safety in Zhejiang province.Based on a summary of Bursaphelenchus xenophiles research, this dissertation analyses the environmental impact(EI) of PWN. The study evaluates the EI of PWN and analyses the cost-benefit ratio of PWN management. This study reached the following conclusions:1)Based on an examination and explanation of the spread of Bursaphelenchus xenophiles, this paper applies the Participatory Rapid Rural Appraisal(PRRA) and Interpretative Structural Modeling(ISM) to the study of the EI of PWN. There are 16 facets within three layers of the impact of PWN.2)After filterting several assessment methods and establishing an index system, this paper provides estimates of the EI of PWN in Zhejiang Province for the year 2004. The PWN cost up to 621 million RMB, which accounts for 0.055% of Zhejiang's GDP, 0.634% of Zhejiang's forestry GDP and has had a severe impact on sustainable development of the environment, society and the economy.3)The result of the PWN management cost-benefit analysis in Zhejiang Province shows that it gained 66.53 million RMB in Net Present Value , excluding the cost of control given a discount rate ic=10% during 2000-2005 for engineering management. An internal rate of return(IRR) of 33.63% was...