北京白河湿地夏季昆虫群落的多样性及空间分布格局

Diversity and Spatial Pattern of Insect Community in Baihe River Wetland,Beijing in Summer

对北京白河湿地14个样地夏季昆虫群落的结构特征进行了比较分析,得到如下主要结果:(1)利用网捕法共捕获昆虫标本15目149科,其中各样地分别捕到44～75科.(2)Shannon-Wiener多样性指数(H')与Pielou均匀度指数(E)显著正相关(r=0.942 9,P<0.001)而与丰富度(S)相关不明显(r=0.237 9,P>0.05);H'在物理环境和植被比较复杂的浅水带样地和紧邻水库的样地较高,而在较干燥的草地和植被稀疏的河边卵石滩样地较低.群落复杂性指数(Cj)的变化与H'大致类似但与丰富度的相关性(r=0.541 9,P<0.05)明显高于均匀度(r=0.336 3,P>0.05).(3)寄生性功能群的丰富度与植食性功能群及中性功能群显著正相关,相关系数分别为0.816 1(P<0.001)和0.771 0(P<0.01),显示出对于宿主昆虫分布特征的高度依赖性.(4)聚类和主成分分析结果表明,不同样地昆虫群落的组成呈现明显分异,反映出湿地昆虫对于栖息地特定小环境的比较明显的选择性.重视湿地多样化生境的保持,对于湿地昆虫多样性的维持具有重要意义.

The structure characteristics of insect communities at 14 plots in Baihe River wetland in Beijing were analyzed in this paper.A total of 149 families belonging to 15 orders were collected by sweep-net sampling,with 44~75 families at each plot.The diversities of the insect communities were comprehensively evaluated and it was shown that the correlation between Shannon-Wiener diversity index（H＇） and Pielou eveness index（E）（r=0.942 9,P0.001） was far significant than that between H＇ and family number（S）（r=0.237 9,P0.05）.H＇ values were higher in two plots near to reservoir and four wading plots complicated in physical environment and vegetations,while lower in plots located at drier grassland or stony beach with rare vegetations.The change of the community complexity index（Cj） among different communities was similar to H＇,but more obviously correlative to S（r=0.541 9,P0.05） than to E（r=0.336 3,P0.05）.Furthermore,the family number of parasitic insects was significantly correlative to those of phytophagous（r=0.816 1,P0.001） and neutral insects（r=0.771 0,P0.01）,which revealed a high dependence of the parasites on their hosts.The results of cluster analysis and principal component analysis presented distinct differentiation in the composition of insects among plots and demonstrated an obvious relativity of the wetland insects to special micro-habitats.It is extremely important to keep the variability of wetland habitats for high insect diversity.