中文摘要：

研究了四川省洪雅县巨桉人工林中小型土壤动物类群及数量分布规律．结果表明，巨桉人工林四季共获中小型土壤动物13550头，分属6门13纲26目，以蜱螨目、线虫纲、弹尾目为优势类群，以线蚓科为常见类群．各样地中小型土壤动物类群数、个体数均有明显季节变化，以秋季或冬季最高，春季最低，夏季次之．中小型土壤动物密度剖面分布表聚性明显，但在5～10cm和10～15cm土层间有时会出现逆向分布现象．中小型湿生土壤动物密度为3．333×10^3～2．533×10^5个·m^-2，中小型干生土壤动物密度为1．670×10^2～2．393×10^5个·m～，中小型湿生土壤动物密度自上而下减少的速率小于中小型干生土壤动物．巨桉人工林中小型土壤动物密度．类群（DG）指数以春季最低，秋季或夏季最高（可达6．637）．巨桉人工林与青冈次生林中小型土壤动物密度及DG指数均无显著差异．

英文摘要：

In this paper, meso-micro soil fauna were extracted and collected by Baermann＇ s and Tullgren＇ s method, and their distribution pattern in the Eucalyptus grandis plantation of Hongya County, Sichuan Province was studied. A total of 13 550 specimens were collected, belonging to 6 phyla, 13 classes, and 26 orders. Acarina, Nematoda, Collembola were the dominant groups, and Enchytraeidae was the frequent one. The group and individual numbers of meso-micro soil fauna varied with seasons, being the maximum in autumn or winter, fewer in summer, and the minimum in spring. The density of meso-micro soil fauna in soil profile decreased rapidly with increasing soil depth, but a converse distribution was observed from time to time in 5 - 10 cm and 10 - 15 cm soil layers. The meso-micro soil fauna collected by Baermann＇ s and Tullgren＇ s method had a density of 3. 333 ×10^3 - 2. 533 × 105 ind · m^ 2 and 1. 670 × 10^2 -2. 393 × 10^5 ind ·m^-2, respectively, and the decreasing rate of the density with the increase of soil depth was higher for those collected by Tullgren＇ s method. The density-group index of mesomicro soil fauna in the E. grandis plantation was the lowest in spring, but the highest in autumn or summer. There were no significant differences in the density of meso-micro soil fauna and in the density-group index between E. grandis plantation and Quercus acutissima secondary forest.