太湖湿地昆虫群落结构及多样性

Abstract

Wetland ecosystems are a special soil resource that has a wealth of species and provide various means for human living.The basic functions of this ecosystem are to adjust the water circle and maintain the habitats for various animals and plants.For example,a large number of insects live in wetland ecosystems and serve as an important food sources for insectivores such as birds.Taihu lake as the second largest freshwater lake in China(30°56′—31°34′N,119°54′—120°36′E) located to the south of Changjiang Delta.To insight into the structure and dynamics of insect community in Taihu wetland,the species richness and diversity of insect community were investigated from May 2010 to September 2011 in this present study.Sample locations included Linghu village,Sanyang village,Yuyangshan mountain,Sanshan island and wetland restoration demonstration area.A total of 24,968 insects were collected,belonging to 318 species,301 genus,88 families and 13 orders.Among them,insects in Hemiptera,Lepidoptera,Coleoptera and Orthoptera were the dominant groups.The species diversity of different locations was evaluated using diversity indices(H′),evenness indices(J) and dominant concentration(C).The results showed that the diversity index(H′) and the evenness(J) were in decrease order of wetland restoration demonstration area Yuyangshan mountain Sanshan island Sanyang village Linghu village.However,the sequence of 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(lnS) and evenness index(J) were used for analyzing the community diversity of different habitats.In all sample locations,the diversity index(H′) was significantly correlated with the evenness index(J)(r = 0.792-0.99,P0.01) but not significantly correlated with the richness index(lnS).The diversity index(H′) of Yuyangshan mountain was relatively stable.Polar ordination analysis showed that the insect community in Yuyang mountain was close to the wetland restoration demonstration area.The principal components analysis indicated that the dominant affective factors of community were predatory and herbivorous insects.Because the proportion of natural enemies was low resulting in low the buffering capacity of insect community in wetland restoration demonstration area against outside disturbance.The above results showed the insect community stability was highest in Yuyang Mountain,but the lowest in Sanyang Village.This study will provide valuable information for studying and protecting wetland resources,and it is extremely important for us to make better use of wetland resources.