河西走廊荒漠土壤微生物群落结构及环境响应

Microbial Community Structure and Environmental Response of Desert Soil in Hexi Corridor

荒漠土壤中微生物生存适应机制及其生态系统功能对揭示干旱区物质转化过程具有重要意义。沿河西走廊东南至西北自然降水递减梯度下设置16个样带,采用高通量测序技术探究土壤细菌和真菌群落多样性特征,揭示微生物多样性、优势菌群与土壤机械组成、养分关系。结果显示:河西走廊荒漠土壤细菌中厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)为优势群落,部分样带厚壁菌门相对丰度最高达85%;真菌中子囊菌门(Ascomycota)和担子菌门(Basidiomycota)为优势群落,其相对丰度均大于>5%。相关性分析显示:粗粉粒(0.05~0.02mm)、细粉粒(0.25~0.10 mm)、黏粒(<0.002 mm)、有效磷(AP)和解碱氮(AN)对细菌多样性影响极显著,细粉粒(0.25~0.10mm)、黏粒(<0.002mm)、有效磷(AP)和解碱氮(AN)对真菌多样性影响极显著(P<0.01)。冗余分析显示:细粉粒(0.25~0.10 mm)、有效磷(AP)和有机碳(SOC)对细菌群落影响显著,黏粒(<0.002 mm)和有效磷(AP)对真菌群落影响显著(P<0.05)。研究表明了河西走廊荒漠土壤微生物群落结构的组成、变化及影响因子,解释了土壤环境对微生物分布的影响及微生物对土壤生态系统系统发展的作用,为保护生物多样性及荒漠生态服务提供理论参考。

【Objective】The survival and adaptation mechanisms of microorganisms in desert soils and their ecosystem functions are of great significance for revealing the process of material transformation in arid areas. 【Method】In this study, 16 transects were set up along the gradient of natural precipitation from the southeast to northwest of the Hexi Corridor. High-throughput sequencing technology was used to explore the characteristics of soil bacterial and fungal community diversity, revealing microbial diversity, dominant flora and soil mechanical composition, and nutrients relationship.【Result】The results showed that Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the dominant communities in the desert soil bacteria of the Hexi Corridor. The abundance of Firmicutes is up to 85%. Ascomycota and Basidiomycota are the dominant fungi communities,and their relative abundances are both greater than >5%. Correlation analysis showed that: coarse powder particles(0.05–0.02mm), fine powder particles(0.25–0.10 mm), clay particles(<0.002 mm), available phosphorus(AP) and alkalization nitrogen(AN) have a great influence on bacterial diversity Significantly, fine powder(0.25–0.10 mm), clay(<0.002 mm), available phosphorus(AP) and alkalization nitrogen(AN) have a significant impact on fungal diversity(P<0.01). Redundant analysis showed that fine powder(0.25–0.10 mm), available phosphorus(AP) and soil organic carbon(SOC) had significant effects on bacterial communities, while clay particles(<0.002mm) and available phosphorus(AP) had significant effects on fungal communities(P<0.05).【Conclusion】The results of this study explored the composition, changes and influencing factors of the desert soil microbial community structure in the Hexi Corridor, explained the influence of the soil environment on the distribution of microbes and the role of microbes on the development of the soil ecosystem, and served to protect biodiversity and desert ecosystem Provide theoretical reference.