生物多样性 ›› 2023, Vol. 31 ›› Issue (8): 23136.  DOI: 10.17520/biods.2023136

• 研究报告: 微生物多样性 • 上一篇    下一篇

不同退化阶段亚高山草甸土壤原生生物群落多样性特征及驱动因素

罗正明1,2, 刘晋仙2, 张变华1, 周妍英3, 郝爱华1, 杨凯1, 柴宝峰2,*()   

  1. 1.忻州师范学院地理系, 山西忻州 034003
    2.山西大学黄土高原研究所, 黄土高原生态恢复山西省重点实验室, 太原 030006
    3.忻州师范学院生物系, 山西忻州 034003
  • 收稿日期:2023-05-04 接受日期:2023-06-29 出版日期:2023-08-20 发布日期:2023-07-05
  • 通讯作者: *E-mail: bfchai@sxu.edu.cn
  • 基金资助:
    山西省应用基础研究计划(202203021221225);山西省应用基础研究计划(202203021222306);山西省高等学校科技创新项目(2021L465);山西省高等学校人文社会科学重点研究基地项目(2022J027);山西省“1331工程”提质增效建设计划项目(2023WTS04)

Diversity characteristics and driving factors of soil protist communities in subalpine meadow at different degradation stages

Zhengming Luo1,2, Jinxian Liu2, Bianhua Zhang1, Yanying Zhou3, Aihua Hao1, Kai Yang1, Baofeng Chai2,*()   

  1. 1. Department of Geography, Xinzhou Normal University, Xinzhou, Shanxi 034003
    2. Institute of Loess Plateau, Shanxi University, Shanxi Key Laboratory of Ecological Restoration on Loess Plateau, Taiyuan 030006
    3. Department of Biology, Xinzhou Normal University, Xinzhou, Shanxi 034003
  • Received:2023-05-04 Accepted:2023-06-29 Online:2023-08-20 Published:2023-07-05
  • Contact: *E-mail: bfchai@sxu.edu.cn

摘要:

原生生物在草地生态系统养分循环、微生物群落稳定和土壤肥力维持方面发挥着重要作用。为了揭示亚高山草甸退化过程中土壤原生生物群落组成和多样性变化格局及环境驱动机制, 本文利用18S rDNA高通量测序技术研究了五台山不同退化阶段(未退化(nondegraded, ND)、轻度(lightly degraded, LD)、中度(moderately degraded, MD)和重度退化(heavily degraded, HD))亚高山草甸土壤原生生物群落组成和多样性的变化特征。结果表明: 丝足门、褐藻门、纤毛门、叶足亚门、锥足亚门、绿藻门和顶复门是亚高山草甸土壤原生生物的优势门(相对丰度 > 1%)。纤毛门、叶足亚门、绿藻门、Choanoflagellida和Perkinsea的相对丰度在4种不同退化程度草甸中存在显著差异(P < 0.05)。LEfSe分析显示未退化草甸中主要富集了Perkinsea类群, 轻度退化草甸中富集了盾纤目类群, 中度退化草甸中富集了变形虫纲和卵菌纲类群, 中度退化草甸中主要富集了绿藻纲和硅藻纲类群等光合自养原生生物。随着亚高山草甸退化加剧, 土壤原生生物群落α多样性呈下降的趋势(P < 0.05)。总氮、植物Shannon-Wiener指数、地上生物量、土壤含水量和铵态氮是土壤原生生物群落结构变化的主要预测因子。方差分解分析(variance partitioning analysis, VPA)结果表明土壤理化因子和植被参数共同解释了原生生物群落结构变异的38.44%, 且土壤理化因子(20.69%)解释度大于植被参数(7.85%)。五台山亚高山草甸退化过程中土壤原生生物群落α多样性和结构均发生了明显的变化, 土壤环境因子是影响原生生物群落结构变化的重要因素。本研究结果加强了原生生物群落作为指示草地退化指标的潜力, 可为科学全面地评价亚高山草甸土壤生态系统健康状况提供数据支撑与参考。

关键词: 亚高山草甸, 草地退化, 原生生物群落, 微生物多样性, 高通量测序

Abstract

Aims: Protists play an important role in nutrient cycling, microbiome stability and soil fertility maintenance. Compared with bacteria and fungi, the change characteristics and driving factors of soil protist community composition and diversity in degraded grassland ecosystems remain unclear. The aim of this study was to explore the community dynamics of soil protists during the degradation of subalpine meadow in Mount Wutai and its driving factors, and to provide basic data and decision-making references for further research on subalpine meadow ecosystem health monitoring and ecological restoration.
Methods: In this study, high-throughput sequencing technology was used to study the change characteristics and environmental driving factors of soil protist community composition and diversity in subalpine meadow of Mount Wutai under nondegraded (ND), lightly, moderately and heavily degraded (LD, MD and HD) conditions. The α diversity of community was analyzed by Shannon-Wiener index and richness index. Non-metric multidimensional scaling analysis (NMDS) based on Bray-Curtis distance was used to assess the overall structural changes of the protist community. Linear discriminant analysis (LDA) combined with LEfSe analysis was used to determine the biomarkers of statistical difference among four different degradation stage of subalpine meadows. The relationship between protist community structure and environmental variables were analyzed by redundancy analysis (RDA). Variance partitioning analysis (VPA) quantified the effects of soil physicochemical properties and plant variables on the changes of protist community structure.
Results: The results showed that the dominant phyla (relative abundance > 1%) of soil protist in subalpine meadows were Cercozoa, Ochrophyta, Ciliophora, Lobosa, Conosa, Chlorophyta and Apicomplexa. There were significant differences in the relative abundances of Ciliophora, Lobosa, Chlorophyta, Choanoflagellida and Perkinsea among the four different degradation stage of subalpine meadows (P < 0.05). LEfSe showed that the ND meadow was mainly enriched with the phylum Perkinsea group, the LD meadow was enriched with the order Scuticociliatida group, the MD meadow was enriched with the Tubulinea and Oomycota groups, and the HD meadow was mainly enriched with the phototrophs, the Chlorophyta and Bacillariophyta groups. The α diversity of soil protists decreased with the deterioration of subalpine meadow (P < 0.05). NMDS results indicated that there were significant differences in the community structure of soil protists in four degradation stages of subalpine meadow (P < 0.05). Total nitrogen, plant Shannon-Wiener index, aboveground biomass, soil water content and ammonium nitrogen were identified as the top predictors for the composition of protist communities (P < 0.05). VPA showed that both physicochemical factors and vegetation parameters jointly accounted for 38.44% of the variation of the protist community, and soil physicochemical factors (20.69%) had a greater explanation than vegetation parameters (7.85%).
Conclusion: The diversity and community structure of soil protists have changed obviously in the process of subalpine meadow degradation in Mount Wutai. Soil environmental factors are important factors affecting the changes of the protist community structure. The results of this study strengthen the potential of protists as indicators of grassland degradation and provide experimental data for scientific and comprehensive evaluation of soil ecosystem health in subalpine meadow.

Key words: subalpine meadow, grassland degradation, protist community, microbial diversity, high-throughput sequencing