中文摘要：

从秦岭太白山南、北坡采集的40个土壤样品中分离纯化得到土壤淡色丝孢真菌16属，利用物种丰富度、Shannon—Wiener多样性指数、均匀度、生态位宽度及生态位重叠等指标对太白山南、北坡不同林带土壤淡色丝孢真菌的群落结构进行了研究．结果表明：土壤淡色丝孢菌各物种在南、北坡各林带中的分布具有明显的环境梯度格局．海拔和植物林带类型是决定太白山土壤淡色丝孢菌分布的主要因素．淡色丝孢真菌物种丰富度和多样性指数随着海拔的升高呈明显降低的趋势；群落的均匀度随海拔的升高呈一定的升高趋势，但规律不明显．对淡色丝孢菌各物种的生态位研究结果表明，太白山南、北坡青霉属、曲霉属、轮枝孢属、拟青霉属、枝顶孢属等物种生态位宽度值较大，与其他各属的生态位重叠较高，说明上述各属真菌在太白山南、北坡分布较广泛．而单端孢属、粘帚霉属、绿僵菌属的生态位宽度较窄，与其他各属的生态位重叠较小，说明这些属的真菌分布受海拔高度及植被类型的影响较大，仅在某些特殊林带中出现．

英文摘要：

Sixteen genera of soil moniliaeeous hyphomyeetes were isolated from 40 soil samples collected from the southern and northern slopes of Taibai Mountain, and the indices Shannon-Wiener diversity index, evenness, niche breadth, and niche overlap were used to analyze the community structure and niche of soil moniliaeeous hyphomyeetes in different forest types on the southern and northern slopes of Taibai Mountain. The results showed that the distribution of soil moniliaeeous hyphomyeetes on the study area had an obvious environmental gradient pattern. Altitude and forest type were the main determinants of the fungal community distribution. The species richness and diversity index of soil moniliaceous hyphomyeetes decreased significantly with increasing altitude, but the community evenness represented an increasing trend. Among the genera of soil moniliaceous hyphomycetes, Penicillium, Aspergillus, Verticillium, Paecilomyces and Acremonium had larger niche width and greater niche overlap with other genera, suggeting that these genera had wide distribution on the southern and northern slopes of Taibai Mountain. As for Trichothecium, Gliocladium and Metarhizium, their niche width was narrower, and their niche overlap with other genera was smaller, indicating that the distribution of these genera was more affected by altitude and vegetation, with the occurrence only in special forest types.