盐池荒漠草地拟步甲昆虫群落时间结构和动态

从2009年3月到10月采用巴氏罐诱导法调查了宁夏盐池四墩子6个不同生境中的拟步甲的群落组成以及时间动态,结果表明,本次调查共采集拟步甲昆虫5431只,计10属20种,个体数最多的是弯齿琵甲Blapsfemoralis femoralis Fischer-Waldheim和克小鳖甲Microdera kraatzi kraatzi Reitter,分别占总数的47.30%和40.66%,不同季节的优势种类不同。从时间动态上看,拟步甲物种数和个体数成显著正相关(r=0.887,P=0.003),表现为5月和7—8月2个发生高峰期,且5月最高。从整个景观来看,优势种克小鳖甲的盛发期在5月和7月,弯齿琵甲的盛发期在5月和8月,不同景观样地略有差异。物种-时间对应分析表明,拟步甲成虫发生可以分为春季发生型、春夏发生型、夏季发生型、夏秋发生型和全年发生型5类。5月拟步甲群落多样性和丰富度最高,不同月的拟步甲群落相似性可以聚为3类,由于植被类型和干扰程度的差异,月间拟步甲群落相似性会有所差异。

The time structure and population darkling beetle community in dynamics of the desert-steppe Yanchi, Ningxia, China

The community composition and seasonal dynamics of darkling beetles in six zones of desert steppe in Sidunzi, Yanchi, Ningxia were investigated using pitfall trapping. A total of 5 431 darkling beetles were collected from 20 species and 10 genera. The dominant species were Blaps femoralis femoralis Fischer-Waldheim and Microdera kraatzi kraatzi Reitter which accounted for 47.30% and 40. 66% of all beetles captured. Various dominant species had different seasonal trends. The abundance of M. kraatzi kraatzi peaked in May and July, whereas that of B. femoralis femoralis peaked in May and August. There was little fluctuation in the abundance of dominant species between different sampling plots. Bio-plots of seasonal variables and the number of darkling beetles individuals from detrended correspondence analysis suggests that darkling beetles can be divided into five types, i. e. , spring, spring-summer, summer, summer-autumn and perennial. The species diversity and abundance index of darkling beetles was higher in May than in other months. Hierarchal cluster analysis indicates that the darkling beetle community could be classified into three groups in different months, and that this classification reflects vegetation type and degree of disturbance.