封育年限对吉林省西部草地昆虫群落组成结构的影响

Effect of Enclosure Period on Structure of Insect Communities on Grassland in Western Jilin Province

2006—2007年5—9月,利用样方框、网捕和诱捕方法对吉林省西部不同封育年限草地昆虫群落进行了连续的系统调查,分析了封育时间、封育方式对昆虫组成结构的影响。结果表明,在不同封育时段草地类型中,其植被生态环境的差异导致了昆虫群落主要类群组成、物种多样性和优势集中性指数的差异。草地昆虫物种丰富度指数随封育时间延长呈下降趋势。自然封育2a的草地昆虫明显比未封育草地的丰富度指数高,而自然封育4a的草地昆虫丰富度指数又下降,基本上与未封育草地持平,自然封育5a的草地昆虫丰富度指数有回升趋势,人工封育5a的草地昆虫丰富度指数除个体数外都偏高。

A continual and systematic investigation on insect communities was conducted on the grasslands enclosed for different years in the western Jilin Province by the methods of quadrat frame,net and trap from May to September in 2006 and 2007.The effect of enclosure period and enclosing method on insect community composition was analysed.Results showed that various ecological environment in grasslands enclosed for different periods of time resulted in the differences in composition of dominant species,species diversity and dominant concentration index of insect communities.Species richness index exhibited a decreasing trend with the prolonged period of enclosure.The species richness index of the naturally enclosed grassland for two years was obviously higher than that of the unenclosed grassland.However,the index of the naturally enclosed grassland for four years went down,basically equaled to that of the unenclosed grassland.The index of naturally enclosed grassland for five years tended to go up,but the insect species richness was higher except the individual quantity.