吉林省西部不同封育年限草地昆虫群落的季节动态变化

对吉林省西部不同封育年限草地中昆虫群落进行了连续2年的调查,结果表明:吉林省西部草地昆虫群落表现出明显的季节动态变化,昆虫种群数量5～7月呈现逐渐上升趋势,到8月上旬达到峰值,9月份随着气温的降低昆虫种群数量显著下降。不同月份草地昆虫群落多样性指数、均匀度指数、丰富度指数、优势集中性指数波动均较大。不同封育阶段草地昆虫群落季节动态变化明显。除未封育草地5月份优势集中性指数超高外,其他月份都处于平稳振荡中。封育年限高,植被种类多、盖度大的草地昆虫群落多样性指数高,人工封育5年草地昆虫群落多样性指数最高,而未封育草地昆虫群落多样性指数最低。

Research on Seasonal Dynamics of Insect Community in Jilin Western Grassland of Different Enclosing Years

Continual and systematic investigation on insect community inJilin western grassland enclosed for different years from May to September in 2006and 2007 had been carried out. Structure and diversity of insect community in all kinds of grassland were identified. The results showed: Insect community in Jilin western grassland appeared seasonal dynamics obviously. Quantity of insect families increased gradually and reached a peak value at the first ten days of August, and decreased significantly with temperature lowering in September. Diversity index, evenness index, richness and mominancy index of insect community fluctuated heavily in different months. Insect community in different enclosing time appeared seasonal  development obviously. Dominancy index of unenclosed grassland kept stable except in May when it was superhigh. Diversity index was high when enclosing time was long,   plants were great in species and grassland had high cover degree. In grassland artificially enclosed for five years, diversity index was the highest, and in unenclosed grassland, diversity index was the lowest.