为研究柳杉Cryptomeria fortunei人工林不同坡位土壤动物群落结构特征，采用手捡法和干湿漏斗法在四川盆周西缘山地3个不同坡位（海拔分别为1088 m，987 m和830 m）的柳杉人工林设置样地（分别为样地Ⅰ，样地Ⅱ和样地Ⅲ）进行土壤动物群落调查。结果显示：试验所采集到的土壤动物平均密度为3.46×104只·m－2，隶属于5门13纲94类，其中，土壤动物密度和类群数均以样地Ⅲ最高，分别为6.53×104只·m－2和66类，以样地Ⅰ最低，分别为1.35×104只·m－2和38类，土壤动物密度和类群数呈现出随坡位高度增加而减少的趋势；从垂直分布来看，各土层土壤动物密度均随着坡位的上升而减少，各样地有大于43%的土壤动物个体分布在0~5 cm土层（凋落物层除外），有大于72%的土壤动物类群分布在凋落物层；除Simpson优势度指数（C）外，土壤动物多样性指数均以样地Ⅲ最高，同时，各样地间土壤动物群落Sorenson相似性系数较Morisita-Horn相似性系数波动更大，表明坡位对柳杉人工林下土壤动物群落各类群的相对数量影响较类群数的影响大。图3表5参20%Soil fauna, an important comp onent of soil ecosystems, plays an important role in decomposition of biological remains, affects soil properties, and enhances material recycling and energy conversion in the soil. Understanding the impacts of slope elevation on soil fauna is essential to achieve sustainable Cryptomeria for-tunei artificial stand management and biodiversity conservation; therefore, an investigation on soil fauna was carried out in Cryptomeria fortunei plantations. Three sample plots were set at three slope elevations (Plot Ⅰ-1 088 m, Plot Ⅱ-987 m, and Plot Ⅲ-830 m). Macrofauna samples (n=3) were picked up by hand in each sampled slope with the area of 50 cm × 50 cm (0.25 m2). After recording the types of soil fauna, the samples were put into a container with alcohol and transported to laboratory for detailed classification to family level. Mesofauna was collected by steel core (r=5 cm, v=100 cm3) and store in soil fauna sealing black bags. The collected samples then were transported to laboratory within 12 h and subsequently separated by Baermann method (for nematodes) and Tullgren method (for mesofauna) over a period of 48 h, respectively. All collected soil fauna were calculated and classified by microscope, and identified to the family level following Pictorial Keys to Soil Animals of China. Analysis was conducted using the following indexes: Sorenson, Morisita-Horn,Shannon-Wiener, Pielou, Simpson, and Density-groups. Results showed a total of 94 soil fauna orders belonging to 5 phyla and 13 classes with an average density of 3.46 × 104 individuals·m-2. The density and number of groups in Plot Ⅲ at lower elevation are significant higher than that in the rest of two plots (P<0.05), and there is no significant difference between the Plots Ⅰ and Ⅱ (P>0.05). Compared to Plots Ⅰ and Ⅱ, the soil fauna density in litter layer and 10~15 cm soil layer of Plot Ⅲ is significantly higher than that in Plots ⅠandⅡ (P<0.05). The vertical study showed that more than 43%of the individuals was found in the 0-5 cm layer and more than 72% of the group number was found in the litter layer in each plot. Plot Ⅲ had the high-est soil fauna density for Phylum Nematoda, and Classes Insecta, Arachnida, and Diplura. The Sorenson and Morisita-Horn indexes showed that slope elevation had a stronger effect on soil fauna density than soil fauna group type. Also, the highest Shannon-Wiener, Pielou, and Density-groups indexes were found in Plot Ⅲ at the lower elevation. Thus, slope elevation affected distribution and diversity of soil fauna in Cryptomeria fortunei plantations, and to reserve litter layer is the key to keep the soil fauna diversity.
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