Abstract:

Based on an investigation conducted between 1991-1992 in 21 Masson (Pinus massoniana) and Black pine (Pinus thunbergii) plots unattacked by pine wood nematode (PWN) in Zhoushan islands of Zhejiang province, the 21 plots were divided into 7 types of succession by SPSS fuzzy clustering with the importance values of regeneration tree species. A comparative analysis was conducted 17 years later between the previous investigated data and a set new survey data collected between 2007-2008 in representative plots of 7 types of succession, integrated with tree species composition, dynamic characteristics, eco-biological characteristics of pine, plant structure, soil, elevation and other factors. Thus, recent pine forests were developed into 8 vegetation types, including deciduous broadleaved forest dominated by Quercus fabric, Liquidambar formosana; evergreen mixed with deciduous broadleaved forest dominated by L. formosana, Q. fabric and Castanopsis sclerophylla or Lithocarpus glaber, Symplocos setchuensis and Q. variabilis; conifer mixed with broadleaved forest dominated by Pinus massoniana, Dalbergia hupeana and Albizia kalkora; deciduous broadleaved forest with sparse density which is dominated by L. formosana or Celtis sinensis; sprouted shrub community dominated by Q. fabric and evergreen shrub community occupied by Eurya japonica etc.. The results showed that the natural succession direction of PWN slash could be defined and judged to some extent. Thus, according to different succession trends, site conditions and cultivation purposes, restoring measures, such as closing forest, artificial afforestation and some other ways, should be adopted as soon as possible. Simultaneously, in the future forestry management, through the papers finding and the former investigation and classification, the succession process and sequence could be deduced and diagnosed quickly. Consequently human intervening and programming could be applied based on different succession directions as soon as possible after the pine wilt disease occurred.

Key words: Bursaphelenchus xylophilus, pine community, natural succession, Zhoushan Island of Zhejiang Praince