热带季节雨林凋落叶分解过程中的中小型土壤节肢动物的群落结构及动态

2000年5月-2001年4月，采用尼龙网袋法，以西双版纳热带季节雨林混合凋落叶作为分解基质，在3个季节雨林样地开展分解实验，对实验过程中分解袋内的中小型土壤节肢动物(meso—microarthropod)进行取样调查。根据所获数据探讨了中小型土壤节肢动物群落在分解过程中的结构和动态。结果显示：(1)在季节雨林凋落叶分解过程中，中小型土壤节肢动物群落组成始终以弹尾目和蜱螨目相对数量较高(均在30％以上)，成为优势类群。(2)分解中期，土壤节肢动物群落多样性指数，类群、个体及重要类群的数量均处于整个分解过程中的较高水平，分解初期和后期相对较低，且波动性大，其中分解初期各多样性指标在波动过程中呈逐步增长趋势，而后期逐步降低，其变化过程受凋落叶数量和质量、林地降雨量变化的影响。土壤动物群落类群和个体相对密度(每克凋落叶干重的类群数和个体数)的变化可在一定程度上反映土壤动物与凋落物质量的动态关系。(3)不同样地间，土壤节肢动物群落结构及动态差异在分解前期不明显，而分解后期差异有所增加，但3样地凋落叶分解物质损失率没有明显差异。

Dynamics and community structure of soil meso-microarthropods during leaf litter decomposition in tropical seasonal rain forests of Xishuangbanna, Yunnan

We examined the dynamics and community structure of soil meso-microarthropods during litter decomposition in tropical rain forests of Xishuangbanna, SW China between May, 2000 and April, 2001. The experiment was carried out in three plots of tropical seasonal rain forest located within a distance of 15 km. Mixed-species litterbags were constructed and placed in the field for one year. Soil meso-microarthropods were extracted from the litterbags by the Tullgren method each month during litter decomposition . The densities of soil meso-microarthropod groups and individuals were calculated per gram of dry litter (relative density). The data showed that Collembola and Acari were the most abundant groups of arthropods in the tropical seasonal rain forests ( above 30% ). Diversity indices, numbers of groups and number of individuals of soil meso-microarthropod were all higher in the middle stage of decomposition than in the early and end stages of decomposition. Variation of soil meso-microarthropod communities, including abundance of some groups, was correlated with litter quantity and quality. Relative density of soil meso-microarthropod reflects the dynamic relationship between litter quality and number of groups and individuals of soil meso-microarthropods during the decomposition process. The differences of diversity and abundance of soil meso-microarthropods among three different plots were higher in the end stage of decomposition than in the early stage of decomposition, but litter weight loss did not differ among the three different study site plots.