生物多样性 ›› 2022, Vol. 30 ›› Issue (12): 22208.  DOI: 10.17520/biods.2022208

所属专题: 土壤生物与土壤健康

• 研究报告 • 上一篇    下一篇

降水格局对北方温带草原土壤微食物网结构的影响

肖宇珊1, 杨昌娆1, 郑国1, 武鹏峰1, 张士秀2, 崔淑艳1,*()   

  1. 1.沈阳师范大学生命科学学院, 沈阳 110034
    2.中国科学院东北地理与农业生态研究所黑土农业生态重点实验室, 长春 130012
  • 收稿日期:2022-04-21 接受日期:2022-07-14 出版日期:2022-12-20 发布日期:2022-08-08
  • 通讯作者: *E-mail: cui.shu.yan@163.com
  • 基金资助:
    国家自然科学基金面上项目(31970410);辽宁省重点研发计划项目(2018103004);辽宁省兴辽英才计划项目(XLYC2002083);辽宁省自然科学基金(2020-BS-150)

Effects of precipitation regime on the structure of soil micro-food web in the grassland of northern China

Yushan Xiao1, Changrao Yang1, Guo Zheng1, Pengfeng Wu1, Shixiu Zhang2, Shuyan Cui1,*()   

  1. 1. College of Life Science, Shenyang Normal University, Shenyang 110034
    2. Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130012
  • Received:2022-04-21 Accepted:2022-07-14 Online:2022-12-20 Published:2022-08-08
  • Contact: *E-mail: cui.shu.yan@163.com

摘要:

全球气候变化背景下, 降水格局发生改变, 呈现降水总量不变, 但降水强度增加、降水频率降低的趋势, 影响了地下生态系统的结构和功能。土壤微食物网作为地下生态系统的重要组成部分, 在驱动生态系统多功能性方面起着重要作用。降水格局的变化能够通过土壤微食物网的改变对生态系统产生影响。然而, 以往研究多关注于降水量的变化对微食物网的影响, 降水格局变化对其影响的研究较少。因此, 本研究在内蒙古温带草原开展连续8年的降水添加控制试验(控制降水总量不变, 降水频率及强度改变), 包括5个降水强度处理(2 mm、5 mm、10 mm、20 mm和40 mm), 通过磷脂脂肪酸法(PLFA)确定微生物含量, 高通量测序法(16S和ITS)确定微生物多样性及群落结构, 线虫形态学鉴定确定线虫群落组成及结构。结果表明在降水总量不变降水强度改变的背景下, 高降水强度(20 mm)促进了北方温带草原真菌含量的增长, 适度降水强度(10 mm)促进了微生物的多样性。而线虫的多度随着降水强度的增加而增大, 中高降水强度下线虫多样性最高。土壤微食物网的变化进一步影响了生态系统多功能性, 主要通过提高真菌生物量、食真菌线虫多度和线虫多样性, 从而提高了生态系统多功能性。

关键词: 降水强度, 降水频率, 土壤微生物, 土壤线虫, 生态系统多功能性

Abstract

Aims: Due to global climate change, precipitation regimes in arid and semi-arid regions are exhibiting a trend of increase in rainfall intensity with a reduction in frequency. These changes in precipitation patterns can affect belowground communities and ecosystem functions. However, previous studies mainly focused on the effects of precipitation amounts on soil micro-food web, the changes of precipitation intensity and frequency on soil micro-food web were relatively few, especially in ecosystem function.
Methods: We performed a field experiment initiated in 2012 to examine the effects of changes in the precipitation regime (i.e. precipitation intensity: 2 mm, 5 mm, 10 mm, 20 mm, and 40 mm). Microbial communities were determined by phospholipid fatty acid (PLFA) and high throughput sequencing (16S and ITS). The composition and structure of the nematode community was determined by morphological identification.
Results: Different precipitation intensities significantly affected soil fungal PLFA, which was highest under the 20 mm treatment. Furthermore, fungal diversity had different responses to precipitation intensity treatment. The abundance of nematodes in each trophic group responded differently to precipitation intensity, and the abundance of bacterivores increased monotonically with the increase in precipitation intensity (P = 0.012). The abundance of fungivores (P < 0.001) and plant parasites (P = 0.046) were both significantly higher in medium (10 mm), high (20 mm) and extrem precipitation intensities (40 mm) than in low precipitation intensities (2 mm and 5 mm). Different precipitation intensities significantly affected soil nematode diversity. All the diversity indices were the highest under medium and high-intensity precipitation (10 mm or 20 mm). The soil nematode community composition was similar between moderate precipitation intensity (10 mm) and extreme precipitation intensity (40 mm). Changes in precipitation patterns increased soil water content, fungal PLFA, and fungivore diversity, thus improving ecosystem multifunction.
Conclusion: High precipitation intensity promoted fungal PLFA in the northern temperate steppe, while moderate precipitation intensity promoted microbial diversity. The abundance of nematodes increased with precipitation intensity, and the diversity of nematodes was highest under moderate and high precipitation intensity. The changes in soil micro-food web further affected ecosystem multifunction, mainly through increasing fungal biomass, abundance of fungivores nematodes, and nematode diversity.

Key words: precipitation intensity, precipitation frequency, soil microbial community, soil nematode community, ecosystem multifunctionality