马尾松林节肢动物群落的稳定性

依据广西大青山马尾松林区马尾松毛虫一个暴发周期中食叶、捕食、寄生、刺吸四大类群多样性指数(H′)、丰富度指数(MD)、均匀度指数(J)和害虫与天敌的数量比例的数据,建立突变模型对马尾松林节肢动物群落的稳定性进行研究,并利用湖南桂阳数据对模型进行了检验.结果表明:在马尾松毛虫的整个暴发过程中,暴发区在暴发年的昆虫生物群落处于明显的不稳定状态,而在非暴发年时,群落则处于亚稳定的状态;非暴发区在暴发年处于亚稳定的状态,非暴发年时处于稳定状态.在松毛虫各个发生阶段,当上升期处于不稳定状态时,有可能导致松毛虫的大发生;松毛虫暴发后,节肢动物群落依旧处于不稳定状态,有可能会造成松毛虫的连续暴发,这主要依赖于各种因子的影响.马尾松毛虫暴发呈现非线性、突变性等特点,食叶类群的影响为马尾松毛虫暴发的关键因子,各类群作用均衡的系统比较稳定,虫害暴发是群落结构趋稳调节过程中的强烈外部表现.研究表明,突变模型在检测群落结构稳定性和预测松毛虫发生上有很好的应用前景.

Analysis of arthropod community stability in mason pine forest

To determine the community stability of arthropods and the dynamics of Mason pine caterpillars (Dendrolimus punctatus Walker), the cusp catastrophe models were developed based on diversity index, richness index, evenness index of defoliators, predators, parasitoids, sap sucking insects and the ratio of pests and natural enemies in Daqing Mountain in Guangxi Province during a complete outbreak of Mason pine caterpillars. The models were tested with data of Guiyang in Hunan Province. The results showed that during the outbreak process of the pine caterpillars, the arthropod communities in the outbreak areas were apparently unstable; in the non-outbreak years, the arthropod communities in the outbreak areas were in a sub-stable state; in the non-outbreak areas, the insect communities were in a sub-stable state in outbreak years, and the arthropod communities were apparently in a stable state in non-outbreak years. During the increasing phrase of the pine caterpillars, the non-stable state of communities would most likely lead to their outbreak. During the declining phrase, if the system was still in a non-stable state, it would also lead to consecutive outbreak, depending on the effects of various factors. The outbreak takes on nonlinear and catastrophic characteristics. Defoliators are the most important regulating factors. A system with various groups evenly related is relatively stable. Pest outbreaks are the expression of the arthropod communities that tend to be stable. This study demonstrates that the cusp catastrophe models can be applied to forecast the stability of arthropod communities and the dynamics of Mason pine caterpillars.Key Words: mason pine; Dendrolimus punctatus Walker; cusp catastrophe model; community; stability