The Diversity And Niche Of Land Insect Community In Taihu Wetland

The present study of Taihu Wetland was done from May2010to September2011in order to approach the species richness and diversity of insect community, to gain insights in the structure and dynamics of this insect community in different locations.The results are as follows:(1) A total of24968insects were collected, belonging to318species,301genus,88families and13orders, among which, Hemiptera, Lepidoptera, Coleoptera and Orthoptera were the dominant taxon. The species diversity of all locations was high. The results reveal that the diversity index (H’) and the evenness (J) was wetland restoration demonstration area> Yuyangshan mountain> Sanshan island> Sanyang village> Linghu village. However, the dominant concentration (C) was wetland restoration demonstration area<Yuyangshan mountain<Sanyang village<Sanshan island<Linghu village. The relationship of diversity index (H’), richness index (InS) and evenness index (J) were used to analyze the community diversity in different sample locations. In all sample locations, the diversity index (H1) was significantly correlated with the evenness index (J)(r=0.792-0.99,p<0.01) but not significantly correlated with the richness index(InS). The diversity index(H’) of Yuyangshan mountain was relatively stable with time. Polar ordination analysis showed that the insect community in Yuyang mountain close to the wetland restoration demonstration area. The principal components analysis showed that the factor dominating the variation was predatory and herbivorous taxon. As the proportion of predatory taxa was low, the buffering capacity of insect community in wetland restoration demonstration area to disturbance was reduced. The conclusion was that the insect community stability was highest in Yuyang mountain but the lowest in Sanyang village.(2) A total of60species of Hemipteran insect were collected, belonging to56genus and16families, of which Pentatomidae and Coreidae are the major families. In all sample locations the diversity indices (H1) and the evenness (J) was wetland restoration demonstration area> Sanshan island> Yuyangshan mountain> Linghu village> Sanyang village. However, the dominant concentration (C) was Sanyang village>Linghu village> Yuyangshan mountain> Sanshan island> wetland restoration demonstration area. The diversity indices (H’) of hemipteran insect community was significantly correlated with the the evenness (J). The richness index (In S) of hemipteran insect in Yuyangshan mountain was the highest in all locations. The Hemipteran insect community of Taihu wetland have been analyzed, by using the curve of Hemipteran insect community species-abundance. The results revealed that only the species rank abundance of Yuyangshan mountain fits a lognormal model. This indicated that the Hemipteran insect community was stable in Yuyangshan mountain.(3) The niche and competition among main groups of insect community in Taihu wetland were studied. The results suggested that the niche breadth of dominant taxon was high and the niche breadth of Hemipteran insect community was the highest but the lowest was the Dermapteran insect community. There were obvious niche overlaps in main groups which used the same resources.The niche overlaps and niche similarity coefficient between some main groups was high, so competition may exist in this groups.