生物多样性 ›› 2021, Vol. 29 ›› Issue (1): 0-0.DOI: 10.17520/biods.2020137

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土壤细菌群落特征对高寒草甸退化的响应

李世雄1,2,3  王彦龙1,2,3  王玉琴1  尹亚丽1,3*   

  1. 1 (青海大学畜牧兽医科学院/青海省畜牧兽医科学院, 西宁 810016)

    2 (三江源区高寒草地生态教育部重点实验室, 青海大学, 西宁 810016)

    3 (青海省高寒草地适应性管理重点实验室, 青海大学, 西宁 810016)

  • 收稿日期:2020-04-03 修回日期:2020-08-10 出版日期:2021-01-20 发布日期:2020-09-30
  • 通讯作者: 尹亚丽

Response of soil bacterial community characteristics to degradation of alpine meadow

Shixiong Li1,2,3, Yanlong Wang1,2,3, Yuqin Wang1, Yali Yin1,3*   

  1. 1 Academy of Animal and Veterinary Science, Qinghai University / Qinghai Academy of Animal and Veterinary Science, Xining 810016

    2 Key Laboratory of Alpine Grassland Ecosystem in the Three-River-Source (Qinghai Univestity), Ministry of Education, Xining, Qinghai Province 810016

    3 Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland, Xining 810016

  • Received:2020-04-03 Revised:2020-08-10 Online:2021-01-20 Published:2020-09-30
  • Contact: ya liyin

摘要: 为明确高寒草甸土壤细菌物种组成及功能结构对草地环境恶化的响应规律, 采用高通量基因检测技术对高寒草甸未退化、轻度退化、中度退化、重度退化和黑土滩退化草地土壤细菌的组成、格局和功能进行了研究。结果表明:高寒草甸土壤优势细菌为变形菌门、酸杆菌门、浮霉菌门、疣微菌门和放线菌门, 在土壤细菌中占比分别为23%‒29%、16%‒18%、9%‒12%、12%‒14%和11%‒12%。草地退化土壤细菌物种组成明显改变, 变形菌门细菌丰度降低, 酸杆菌门和浮霉菌门丰度增加, 不同草地科水平细菌丰度差异因土层而异。草地退化对细菌Chao1指数无影响, 轻度退化提高了细菌Simpson指数, 重度退化草地土壤细菌Shannon指数最高。Faprotax细菌功能分组以化能异养、硝化作用、亚硝酸盐氧化及硫代谢作用为主, 草地退化改变了微生物介导的碳循环、氮循环、硫循环、铁循环和锰循环。重度及黑土滩退化提高了细菌氨氧化功能作用, 降低了硫化物、亚硝酸盐氧化及尿素水解作用; 草地退化过程中细菌化能异养、芳香族化合物降解及反硝化作用功能等均呈先降低后升高的变化趋势, 中度退化阶段是微生物群落生态功能结构转变的拐点。高寒草甸退化改变了土壤细菌的群落及功能结构, 土壤含水量、pH、总有机碳、全氮、全钾和有效氮磷比是土壤细菌群落及功能结构变化的主要驱动因子。

关键词: 退化高寒草甸, 土壤细菌, 物种组成, 群落特征, 生态功能结构

Abstract:

To clarify the response of species composition and functional structure of soil bacteria to grassland environmental degradation in the alpine meadow, the bacteria composition, pattern and function in non-degraded, lightly-degraded, moderately-degraded, severely-degraded and extremely-degraded alpine meadows at the three rivers source region, were studied by high-throughput gene detection techniques. The results showed that the dominant bacteria in alpine meadow soil were Proteobacteria, Acidobacteria, Planctomycetes, Verrucomicrobia and Actinobacteria, and they were accounting for 23%29%, 16%‒18%, 9%‒12%, 12%‒14% and 11%‒12%, respectively. The soil bacterial species compositions changed obviously by grassland degradation, the Proteobacteria abundance decreased, while the abundance of Acidobacteria and Planctomycetes increased significantly, and the species on genus level were different at diverse soil layers in degraded alpine meadows. Grassland degradation had no effect on bacterial Chao1 index, lightly-degradation increased bacterial Simpson index, and soil bacterial Shannon index in severly-degraded grassland was the highest. The FAPROTAX functions are mainly composed by Chemoheterotrophy, nitrification, nitrite oxidation and sulfur metabolism. Grassland degradation changed the cycle of carbon, nitrogen, sulfur, iron and manganese, which mediated by microorganisms. Severe and extreme degradation increased the bacterial ammonia-oxidizing function, and decreased the functions of sulfide, nitrite oxidation and ureolysis. In the process of grassland degradation, the bacteriological Chemoheterotrophy, aromatic compounds degradation and the denitrification functions all showed a trend of decreasing first and then increasing variation trends, and the moderate degradation stage was the turning point of the bacterial community ecological functional structure changes. The degradation of alpine meadow changed the soil bacterial community and functional structures. Soil moisture content, pH, total organic carbon, total nitrogen, total potassium, and the ratio of available nitrogen and phosphorus were the main driving factors for the differences in soil bacterial community and functional structures.

Key words: Degraded alpine meadow, soil bacteria, species composition, community characteristics, ecological functional structures