荔枝果园植物群落动态变化及其对昆虫多样性的影响

Effects of dynamic variety of plant community on insect diversity in litchi orchard

果园生态系统的植物多样性是害虫天敌多样性的基础。以广西横县境内莲州路荔枝果园为样本,调查其中草本植物的种类和数量,从群落物种的4个特征指数(丰富度指数、多样性指数、均匀度指数及优势集中性指数)来分析果园植被多样性状况及季节性变化规律;同时调查分析果园栖生昆虫的种类、数量和4个相关性指数,探讨果园植被多样性与昆虫多样性的相关关系。结果表明,4～9月间,果园植物多样性指数在0.842～1.370之间;物种均匀度指数在0.445～0.659之间;优势集中性指数在0.326～0.518之间。昆虫与植被多样性指数峰值出现的时间基本同步,都在5～6月间。植被多样性指数较小起伏可导致昆虫多样性指数较大波动,说明栖息地植被多样性变化对昆虫群落的结构和组成产生较大影响,昆虫多样性与栖息地植被多样性密切相关。

Vegetation diversity is the basic of the diversity of natural enemies in orchard ecosystem. In this study,species and quantity of herbaceous plants of the Lianzhoulu Litchi Orchard were investigated in Heng County,Guangxi. Vegetation diversity in the orchard and its changing laws were studied by analyzing 4 characteristic indexes（species richness index; species diversity index; species evenness index; dominant concentration index）. At the same time, the species and quantity of insects dwelling in the orchard were researched, the same 4 characteristic indexes of insect community were also calculated. The results showed that species diversity indexes, species evenness indexes and dominant concentration indexes of orchard vegetation were 0. 842- 1. 370,0. 445-0. 659 and 0. 326-0. 518 during April to September respectively. Peak values of diversity indexes of the vegetation appeared simultaneously with that of the insects,both in May to June. A narrow range fluctuation of vegetation diversity indexes caused a large range alteration of the insect diversity indexes, suggesting that the vegetation diversity of orchard markedly worked on the structure and the components of the dwelling insects. There were a closed correlation between vegetation diversity and insect diversity.