中文摘要：

为了解西藏东南部亚高山地带典型森林群落类型——急尖长苞冷杉林土壤生态系统线虫多样性现状，于2010年夏季至2011年春季，调查了0～30cm范围内不同深度土层的土壤线虫群落，用线虫个体密度、多样性指数和营养类群指数等特征值分析了土壤线虫群落的组成与结构特点．调查采用浅盘法分离得到土壤线虫7915条，隶属于2纲6目38科67属；线虫个体密度平均为620条·100g^-1干土；表层（0～5cm）土壤中线虫个体数量占总数的56．9％，表聚性明显．垫咽属、螺旋属及绕线属为优势属．植食性线虫是主要营养类群，非植食线虫中食真菌性线虫所占比例最大．土壤有机质以真菌分解途径为主．土壤线虫群落H’多样性指数性、J’均匀度指数、λ优势度指数及艘丰富度指数季节间差异均不显著，不同土层间的J＇均匀度指数差异不显著，H＇多样性指数、λ优势度指数及职丰富度指数土层间的差异随土壤深度加深而增大．表明色季拉山急尖长苞冷杉林生态系统成熟度较高，抵抗外界干扰的能力较强．

英文摘要：

In order to understand the present status of nematode diversity in soil ecosystem of Abies georgei var. smithii forest, the typical forest type in subalpine zone of southeastern Tibet, an investigation was made on the nematode community in different soil layers of 0-30 cm depth from the summer, 2010 to the spring, 2011. The nematode individual density, diversity index, and trophic group index were taken to analyze the composition and structural characteristics of the soil nematode community. A total of 7915 soil nematodes belonging to 2 classes, 6 orders, 38 families, and 67 genera were collected by shallow dish method. The nematode individual density was averagely 620 nematodes ·100 g^-1 dry soil, and the nematode individuals in surface soil layer （0-5 cm） accounted for 56.9% of the total, indicating the obvious surface gathering characteristics of the nematode community. Tylencholaimus, Helicotylenchus, and Plectus were the dominant genus. Plant-parasite nematode was the dominant trophic group, while fungi-feeding nematode had the largest proportion among the non plant-parasite nematodes. Soil organic matter was mainly decomposed by fungi. The ANOVA analysis indicated that there were no significant differences in the Shannon, Pielou, Margalef, and Simpson indices of soil nematode community among different seasons. The Pielou index had no significant difference among different soil layers, while the differences of Shannon, Margalef, and Simpson indices tended to be increased with increasing soil depth. It was concluded that the A. georgei var. smithii forest ecosystem in Sejila Mountain had a high maturity, with strong resistance to environment disturbances.