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The Composition And Diversity Structure Of Arthropod Community In Pine Forest Ecosystem Invaded By Bursaphelenchus Xylophilus

Posted on:2009-11-05Degree:DoctorType:Dissertation
Country:ChinaCandidate:H W WuFull Text:PDF
GTID:1103360242992509Subject:Forest Protection
Abstract/Summary:PDF Full Text Request
Biological invasion has become one of the most important factors which threaten biodiversity and ecological environment of China with the development of global trade, transportation, international travel and ecological tourism. As a destructive forestry invasive alien species, the invasion of Bursaphelenchus xylophilus (Steiner et Buhrer) Nicklehas caused a great damage to the pine forest's resource of China, especially to pine forest and ecological region in southern China. Definituding the invasion impact of B. xylophilus on the composition and structure of arthropod community will bring a great significance to establish methods and techniques of integrate pest management (IPM) and reveal the resistance mechanism of pine forest ecosystem to the invasion of B. xylophilus in both theory and practice aspects.In this paper, based on the research objectives of pine forests in different damage degree after the invasion of pine wood nematode in Fuyang and Zhoushan county, Zhejiang province, the responses of arthropod community affected by different managing ways on infested pines after PWN's invasion were analyzed. Meanwhile, as for such two different habitats as island and inland, especially four typical forest types in islands, for which the composition and structure of arthropod community was studied with a detail. Furthermore, the composition and structure of canopy arthropods of Pinus massoniana and P. thunbergii and the relationship between stand factors and arthropod composition was also discussed and analyzed. The main results are as follows.1. The responses of arthropod community affected by the disturbance degree of removing trees were analyzed under three levels, such as species, sub-community and nutrient classes. The species richness decreased significantly after clear cutting, and some orders such as Lepidoptera, Coleoptera, Hemiptera and Araneae were the guilds that were influenced most heavily. The analysis of sub-community structure showed that both pests and natural enemies were great impacted. The proportion composition of energy classes were also changed after clear cutting. As for the studying sample plots,The community structure of arthropod in young Masson pine forests showed more rational than that in mixed forest of Quercus fabric and Pleioblastus amarus. While with the removal of infected trees, both the richness and species diversity of total arthropod community and sub-community were obviously increasd. The nutrition structure of arthropod community also was ameliorated, which played a positive role in promoting the succession of arthropod community.2. The composition and structure of arthropod community in island was compared with that in inland, the composition of different arthropods guilds Hierarchical Cluster Analysis(HCA) and One-way ANOVA was performed and the results showed that there was no significant difference for the composition of arthropod community in family level between inland and island. But those two habitats had significant difference in the species composition, individuals, sub-community and the energy classes level, in which, Lepidoptera and Diptera is most seriously.3. Based on G-test, Classic Sorensen incidence-based sample similarity index and Classic Jaccard sample similarity index, the composition of arthropod community in 4 representative pine forests infested by B. xylophilus, which is mixed stands of P. elliottii and Cunninghamia lanceolata, sparse Masson pine stands, pure Masson pine stands and mixed stands of P. thunbergii and P. massoniana respectively, were compared in Zhoushan city, Zhejiang province. Meanwhile, the total species richness of the above four forest types was estimated using Chao 1 and ACE index. The results showed that there was a significant difference in families, species and individual number of arthropod community among four pine forest types, where, G3=9.303, P=0.026 for the families number, G3=57.362,P=0.000 for the species number, G3=2767.568,P=0.000 for the individual number. The arthropod community similarity between sparse Masson pine stands and pure Masson pine stands was highest, whereas, the lowest value happened between the two mixed forest stands.4. Composition and structure of canopy arthropods in young and old P. massoniana stands were studied in Zhoushan city, Zhejiang Province. The technique of branch bagging was used. The results show that the number of arthropod species was significantly higher in the canopy of young stands than in that of old ones, but the individual number of arthropods was much higher in the canopy of the old stands. The major species in the canopy of young stands included Monochamus alternatus Hope, Cinara pinitabulaeformis Zhang et Zhang, Dioryctria rubella Hampson, Tomicus piniperda L., Aphrophora flavipes Uhler and others. In the canopy of old stands, the predominant species were M. alternatus and C. pinitabulaeformis as well as Nesodiprion zhejiangensis Zhou et Xiao and Epinotia rubiginosana Herrich-Sch?ffer, which, to a lesser extent, also occurred in the canopy of young stands. A total of 4218 arthropods, representing 98 species which belong to 49 families and 13 orders, was found in 90 tree canopies, pooled from both the young and old stands. In which, a total of 1584 arthropods, representing 66 species belonging to 40 families and 12 orders, was found in the canopy of young stands and 2634 arthropods from 74 species belonging to 39 families and 12 orders were found in the old stands. The structure of the arthropod community in the canopy of both types of stands was also compared in spatial and temporal terms which showed that the structure of young trees was more suitable than that of old trees for harboring arthropods, which suggests that the tending of old trees should be strengthened.5. The composition and structure of canopy arthropods in P. thunbergii was studied in Zhoushan city, Zhejiang province. A total of 3077 individuals representing 95 species which belong to 45 families and 12 orders was found in 60 tree canopies in which a total of 89 individuals representing 17 species which belong to 10 families were predaceous insects, a total of 1477 individuals representing 16 species which belong to 11 families were leaf-feeder insects, a total of 1186 individuals representing 18 species which belong to 8 families were branch and top-feeder insects, a total of 287 individuals representing 33 species which belong to 11 families were spiders and a total of 38 individuals representing 13 species which belong to 5 families were'tourists'. The main species including Nesodiprion zhejiangensis Zhou et Xiao,Drosicha corpulenta (Kuwana), Aphrophora flavipes Uhler, Monochamus alternatus Hope and so on. All functional groups mostly distributed in the mid and lower layers of the canopy. Except for predaceous insects, all the other groups had no selectivity to the orientations. They preferred staying in the sunny parts of the canopy such as east, south and west. The dominance of pests including leaf-feeder group and branch and top-feeder group was highest in May and the species richness was highest in July. The great damage occurred between June and August. Predaceous group including predaceous insects and spiders had a steady dominance in every month.6. The relationship between the diversity structure of arthropod community and stand factors and the influence of the plant community on the arthropod community were analyzed through canonical correlation analysis and double screening by stepwise regression analysis. It was found that litter layer thickness, canopy density, stand density and the herbaceous layer coverage were the main factors that impacted the arthropod community diversity, the litter layer thickness, herbaceous layer coverage and crown breadth of dominant tree were the main factors that impacted the structure of energy classes of arthropod community. The diversity of plant communities had a significant impact to the diversity of arthropod community. The factors referred to all levels of the plant community structure and the relationship between sub-community of natural enemies or neutral insect pests and plant community showed most notable. It could be seen from the diverse impact factors that one or several factors couldn't affect the variety of arthropod community, but the overall effect of plant communities.
Keywords/Search Tags:Bursaphelenchus xylophilus, Pinus massoniana, Pinus thunbergii, Biological invasion, arthropod, community structure
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