欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2023, Vol. 32 ›› Issue (6): 30-44.DOI: 10.11686/cyxb2022298

• 研究论文 • 上一篇    下一篇

荒漠草原不同年限灌丛引入过程土壤细菌碳源利用特征

陈彦硕(), 马彦平, 王红梅(), 赵亚楠, 李志丽, 张振杰   

  1. 宁夏大学农学院,宁夏草牧业工程技术研究中心,西北退化生态系统恢复与重建教育部重点培育实验室,宁夏 银川 750021
  • 收稿日期:2022-07-25 修回日期:2022-09-07 出版日期:2023-06-20 发布日期:2023-04-21
  • 通讯作者: 王红梅
  • 作者简介:Corresponding author. E-mail: whm_826@163.com
    陈彦硕(1998-),男,甘肃白银人,在读硕士。E-mail: 2493193280@qq.com
  • 基金资助:
    国家自然科学基金项目(31860677);宁夏高等学校一流学科建设项目(NXYLXK2017A01)

Carbon source utilization by soil bacteria at different lengths of time after introducing shrubs to the desert steppe

Yan-shuo CHEN(), Yan-ping MA, Hong-mei WANG(), Ya-nan ZHAO, Zhi-li LI, Zhen-jie ZHANG   

  1. School of Agriculture,Ningxia University,Ningxia Grassland and Animal Husbandry Engineering Technology Research Center,Key Cultivation Laboratory of Ecosystem Restoration and Reconstruction,Ministry of Education,Yinchuan 750021,China
  • Received:2022-07-25 Revised:2022-09-07 Online:2023-06-20 Published:2023-04-21
  • Contact: Hong-mei WANG

摘要:

为探究不同年限灌丛引入对荒漠草原土壤细菌群落功能多样性的影响,利用Biolog-ECO法对封育草地(17 a)和不同年限引入灌丛地(6,15,25 a)0~20 cm土层展开土壤细菌群落的碳源利用特征研究。结果表明:荒漠草原不同年限灌丛引入后土壤全碳均有所增加,其中25 a时全碳最高,较封育草地显著增加43.5%(P<0.05),有机碳差异不显著,细菌数量与微生物生物量碳均在引入25 a最高,蔗糖酶活性随灌丛引入年限增加显著升高。土壤细菌群落随灌丛引入年限延长对碳源利用程度显著增大,平均增幅92.75%~181.73%,且对6类碳源利用能力均高于封育草地,其中糖类、氨基酸类、羧酸类是引入过程中细菌优先利用的3类碳源。灌丛引入也显著增加了土壤细菌群落功能多样性,特别是Shannon-Wiener丰富度指数、Shannon均匀度指数和Simpson优势度指数随引入年限延长而增大,且土壤全碳、全氮与细菌群落功能多样性呈显著正相关(P<0.05)。综上,近30 a灌丛引入不仅提高了土壤细菌对不同碳源的利用程度,也改变了主要碳源利用类型,从草地的氨基酸、聚合物类等转向灌丛地糖类、氨基酸类为主。

关键词: 荒漠草原, 灌丛, 引入年限, 土壤细菌功能多样性

Abstract:

The aim of this study was to explore the impact of the introduction of shrubs over recent decades on the functional diversity of soil bacterial communities in the desert steppe. Therefore, the carbon utilization characteristics of soil bacteria in the 0-20 cm soil horizon were investigated and analyzed. Soil samples were collected from fenced grassland (17 yr), and grassland at 6, 15 years, and 25 years after the introduction of shrubs. The soil samples were analyzed using the Biolog-ECO method. It was found that the soil total carbon content was up to 43.5% (P<0.05) higher in shrubland than in fenced desert grassland, but did not differ significantly among the three shrublands. The amounts of bacteria and microbial biomass carbon were highest in the 25-year shrubland. Sucrase activity in soil increased significantly with increasing number of years after shrub introduction. Compared with the soil bacterial community in enclosed desert grassland, those in the shrublands showed increased utilization of soil carbon sources (by 92.75%-181.73%). The utilization capacity of six types of carbon sources by soil bacteria was significantly higher in the shrublands than in the enclosed grassland. Sugar, amino acids, and carboxylic acids were the three types of carbon sources preferentially utilized by soil bacteria. The introduction of shrubs into the desert steppe significantly increased the functional diversity of soil bacterial communities, especially in terms of the Shannon-Wiener richness index, Shannon’s evenness index, and Simpson’s dominance index, and the values of these indexes increased with increasing number of years after shrub introduction. The soil total carbon and nitrogen contents were significantly and positively correlated with the functional diversity of soil bacteria (P<0.05) after the introduction of shrubs. To summarize, nearly 30 years after shrub introduction, the bacterial utilization of carbon sources had significantly improved, accompanied by a shift of the main types utilized from amino acids and polymers in grassland to sugars and amino acids in shrubland.

Key words: desert steppe, shrub, years of introduction, functional diversity of soil bacteria