摘要:生物多样性的海拔分布格局与维持机制是生物多样性与生态系统功能研究的热点领域。尽管微生物驱动着地球上许多重要的生物地球化学循环，但与大型生物体相比，对微生物多样性海拔梯度分布格局知之甚少。运用Illumina Miseq高通量测序技术，全面分析了五台山亚高山生态系统（海拔2000-3058 m范围内）土壤真菌群落组成和多样性变化特征。结果表明，子囊菌门（Ascomycota）、担子菌门（Basidiomycota）、接合菌门（Zygomycota）、壶菌门（Chytridimycota）为主要的优势菌门。非度量多维尺度分析（NMDS）和相似性分析（ANOSIM）表明真菌群落组成和结构在海拔梯度上存在显著的差异（P<0.05）。典范对应分析（CCA）显示pH、植物丰富度、总碳含量与土壤真菌群落结构存在显著相关性（P<0.05）。局域海拔尺度上，土壤真菌多样性与植物多样性（α和β多样性）呈显著正相关关系（P<0.05）。方差分解分析（VPA）和偏Mantel分析表明土壤真菌群落构建过程中，环境因子和空间变量都起作用，并且环境因子占绝对的优势。土壤真菌群落之间的Bray-Curtis距离与海拔距离呈显著正相关关系（P<0.05），说明环境选择是亚高山土壤真菌海拔分布格局的决定因素。总之，五台山亚高山沿海拔梯度土壤真菌群落结构和多样性产生明显的变化，群落构建主要由确定性过程和随机过程驱动，但确定性过程占主导地位。土壤pH、植物丰富度、总碳含量是影响土壤真菌群落结构的重要因素。



Abstract:The elevational distribution pattern and maintenance mechanism of biodiversity are critical issues for the comprehensive study of biodiversity and ecosystem functioning. Compared with macroorganisms, we know very little about the patterns of microbial diversity across elevational gradients, though microbes drive many important biogeochemical cycles on earth. In this paper, we used Illumina Miseq high-throughput sequencing technology to comprehensively analyze the variation characteristics of soil fungal community composition and diversity in the subalpine ecosystem of Mount Wutai (altitude of 2000-3058 m above sea level). The results showed that Ascomycota, Basidiomycota Zygomycota, Chytridimycota were the dominant soil fungal phyla. Non-metric multidimensional scaling (NMDS) and similarity analysis (ANOSIM) indicated that the compositions and structures of fungal communities were significantly different among the elevation gradients (P<0.05). Canonical correspondence analysis (CCA) showed that there were significant correlations between pH, plant richness and total carbon content and soil fungal community structure (P<0.05). There was a significantly positive correlation between soil fungal diversity and plant diversity (α and β-diversity) at local elevation scale (P<0.05). Variance partitioning analysis (VPA) and partial Mantel analysis showed that both environmental factors and spatial variables played roles in the assembly of soil fungal community, and environmental factors were dominant. The Bray-Curtis distance between soil fungal communities was significantly and positively correlated with the elevation distance (P<0.05), indicating that environmental selection was the determinant of the elevation distribution pattern of soil fungal communities. In conclusion, there were significant differences in the structure and diversity of soil fungal communities along the elevation gradient of Mount Wutai, and the assembly mechanism of fungal communities was mainly determined by deterministic processes. The soil pH, plant richness and total carbon content may be the most important factors affecting the soil fungal community structure.





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