Abstract:

Soil microorganisms play a crucial role as “regulators” of soil life in maintaining the balance of forest ecosystems and soil nutrients. Picea schrenkiana forests is an important ecological barrier and precious biological resource in the Tianshan Mountains, and its carbon sequestration capacity of the ecosystem continues to improve. So, exploring the characteristics of soil microbial communities and the interaction between microorganisms and soil nutrients in P. schrenkiana forests is crucial for maintaining the quality of P. schrenkiana forests ecosystem and promoting its sustainable development. In this study, the surface soil (0-20 cm) of P. schrenkiana forests was taken as the research object, and metagenomics technology was used to explore the composition, diversity, and influencing factors of the soil microbial community in P. schrenkiana forests on the northern slope of the Tianshan Mountains in Xinjiang, China. The results showed as following: 1) The relative abundance of bacteria in the microbial community of the P. schrenkiana forests in different regions on the northern slope of Tianshan Mountain was 82.5%, with fungi accounting for 1.3%, archaea accounting for 0.5%, and other microorganisms accounting for 15.7%. 2) An alpha-diversity analysis showed no significant differences in the archaeal and fungal diversity among different regions, while the bacterial diversity differed significantly between the central-eastern and western regions (P<0.05). A beta-diversity analysis revealed significant differences between the central and western regions (P<0.05) and extremely significant differences between the central and eastern regions (P<0.01) for the archaeal community. There were significant differences between the three regions for the bacterial community (P<0.05), with an extremely significant difference between the western and eastern regions (P<0.01). An extremely significant difference was found between the central and eastern regions for the fungal community (P<0.01), and 3) The diversity of soil archaea was primarily influenced by the SOC, TN, pH, and SM. The bacterial diversity was primarily influenced by the nitrogen, pH, MAP, and MAT. The fungi diversity was primarily influenced by the MBC and MAT. Overall, soil factors and hydrothermal conditions play a significant role in the distribution of soil microbial communities in the P. schrenkiana forests on the northern slope of the Tianshan Mountains, with pH and average annual temperature serving as the dominant factors that drove the spatial differentiation among the microbial groups. This study explored the regulatory role of environmental factors on the distribution of soil microorganisms in P. schrenkiana forests and provided a basis for forest management and sustainable development in the future.

Key words: Tianshan Mountains, Picea schrenkiana, soil microorganisms, environmental factors, metagenome

摘要：

土壤微生物是维持森林生态系统平衡与土壤养分的一个重要因素。雪岭云杉林是天山重要的生态屏障和珍贵生物资源，其生态系统的固碳能力持续提升。研究雪岭云杉森林土壤微生物群落特征及微生物与土壤养分之间的互作关系，对维持雪岭云杉森林生态系统质量，促进雪岭云杉森林生态系统可持续发展至关重要。以天山北坡雪岭云杉林表层土为研究对象，利用宏基因组技术，探究天山北坡雪岭云杉林土壤微生物群落组成和多样性及其影响因素。结果表明，天山北坡雪岭云杉林土壤微生物群落特征表现为细菌相对丰度82.5%，真菌1.3%，古菌0.5%，其他15.7%。细菌Alpha多样性在中东部和西部之间有显著性差异；古菌Beta多样性在中部与西部存在显著差异，且中部和东部之间极显著；细菌Beta多样性在3个区域之间均有显著差异，其中西部与东部极显著；真菌Beta多样性仅中部与东部存在极显著差异。古菌多样性主要受有机碳、总氮、pH和土壤湿度的影响；细菌多样性主要受氮素、pH、年均降水量和年均摄氏温度的影响；真菌群落多样性主要受微生物碳和年均摄氏温度的影响。综上说明，土壤因素和水热条件在天山北坡雪岭云杉林土壤微生物群落分布中起主要控制作用，其中pH值和年均摄氏温度是微生物类群空间分异的主导因素。该研究探讨了环境因子对雪岭云杉林土壤微生物分布的调控作用，为今后森林的经营和可持续发展提供依据。

关键词: 天山, 雪岭云杉, 土壤微生物, 环境因子, 宏基因组