The Ecological Quantitative Study Of Soil Mesofauna And Collembolans At Shell Islands Of Yellow River Delta

In order to find out the ecological condition and law of the soil inesofauna at shell islands of Yellow River Delta(YRD), the writer made an ecological quantitative research on group composition, quantity distribution, seasonal variation, vertical migration, biodiversity, similarity etc. We investigated the soil fauna communities at shell islands of the Yellow River Delta in Wudi, Shandong from May to October 2008 by Tullgren funnel. Furthermore, the author also studied on collembolans specially in above mentioned aspects.There were 15312 individuals of soil fauna belonged to 10 orders, 7 classes and 1 phylum in total. The dominant groups were Collembola and Acari as well as the frequent group was Hymenoptera. The remnant were rare groups. Shannon-Weiner index(H) tended E>C>B>F>D>A, the Simpson index was low, because the percent number of Collembola and Acari were both overpass 40%. The highest value was only 0.4927. The soil mesofauna and microfauna in vertical distribution had no obvious surface accumulation. According to the cluster result of Bray-Curtis Similarity Coefficient, all 6 communities were classed to 3 groups, which showed the response of soil mesofauna and microfauna communities to the different spots.Totally 7461 individuals of soil collembolan belonged to 17 genus, 7 families and 4 orders were obtained in all samples, among which Onychiurus and Folsomia were dominant groups amounting to 79.25% of the total. Hypogastrura,Neanura,Xenylla and Isotoma were the frequent groups and their amount reached 15.91% of the total, leaving the remnant were rare groups. The variation laws of Shannon-Weiner diversity index, Margaleff richness index and index of Pielou evenness were similar, contrary to that of Simpson dominance index. The monthly dynamics of diversity was August>July>September>October>May>June.It is the first time that ecological research on soil fauna at shell islands of Yellow River Delta was made. The accomplishment of this subject have significance to protect the unique but fragile ecosystem, rehabilitate the deteriorating ecological environment of shell islands and realize the importance of sustainable development in a given range.