Abstract: To explore the horizontal distribution patterns and driving factors of soil fungal communities in degraded alpine meadows,in this study we employed a nested sampling approach within a 1 000 m×1 000 m area of moderately degraded meadow. We comprehensively analyzed the variation in species diversity and functional composition of soil fungal communities at different sampling distances and identified the main environmental factors that driving the distribution of soil fungal communities. The results indicated that there were significant differences in α-diversity and community structure of soil fungi at different sampling distances,suggesting that the heterogeneity of degraded meadow environments leads to the changes in fungal communities. Functional predictions using FunGuild revealed an increase in saprotrophic and pathogenic soil fungi in degraded meadows,indicating that changes in above-ground vegetation communities during meadow degradation resulted in the shifts in the nutritional types of soil fungi. Furthermore,soil nutrient composition emerged as the primary environmental factor driving the horizontal distribution patterns of soil fungal communities in the degraded meadows. These findings indicate that the spatial distribution of microbial diversity is influenced by various environmental factors,with alterations in soil nutrient composition being particularly impactful on microbial spatial distribution in degraded grassland ecosystems.

Key words: Degraded meadow, Soil fungi, Community composition, Functional composition, Spatial distribution

摘要： 为探讨退化高寒草甸土壤真菌群落水平分布格局及驱动因子，本研究采用嵌套式取样方法在1 000 m×1 000 m的中度退化草甸区域内，综合分析了土壤真菌群落在不同取样距离上物种多样性和功能组成的变化规律及驱动土壤真菌群落分布的主要环境因子。结果表明：在不同取样距离上，土壤真菌的α多样性和群落结构存在显著的差异，退化草甸环境异质性可导致真菌群落的变化。FunGuil功能预测表明草甸退化使得腐生型和病理性土壤真菌增加，草甸退化过程中地上植被群落的改变可导致土壤真菌营养型的变化。此外，土壤营养成分是驱动退化草甸土壤真菌群落水平分布格局的主要环境因子。因此，微生物多样性空间分布受控于不同的环境因素，而土壤营养成分的改变容易引起退化草地生态系统中微生物的空间分布变化。

关键词: 退化草甸, 土壤真菌, 群落组成, 功能组成, 水平分布