太湖湿地昆虫群落结构及多样性

为了探讨太湖湿地昆虫群落的结构和变化规律,对太湖湿地各生境样点昆虫群落进行了调查研究.调查共获得昆虫标本24968号,隶属于13目88科301属318种；半翅目、鳞翅目、鞘翅目和直翅目等为优势类群.各样点昆虫群落多样性指数和均匀度指数特征值为湿地恢复示范区＞渔阳山＞三山岛＞三洋村＞灵湖村,优势集中性指数的特征值比较为:湿地恢复示范区＜渔阳山＜三洋村＜三山岛＜灵湖村.各样点昆虫群落的多样性指数与均匀度指数和丰富度指数表现一致.在时间序列上渔阳山样点昆虫群落的多样性指数波动最小.昆虫群落的极点排序表明渔阳山和湿地恢复示范区样点昆虫群落是最相近的.主分量分析的结果显示太湖湿地昆虫群落主要受捕食性和植食性昆虫群落的影响.湿地恢复示范区样点昆虫群落内天敌昆虫比例偏低,降低了昆虫群落对外界扰动的缓冲能力.综合昆虫群落的各项分析结果发现渔阳山样点昆虫群落稳定性最高,三洋村样点昆虫群落稳定性最低.

The structure and diversity of insect community in Taihu Wetland

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, P<0.01) 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.