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): 58-70.DOI: 10.11686/cyxb2022267

• 研究论文 • 上一篇    下一篇

封育对蒿类荒漠草地土壤有机碳及土壤微生物生物量生态化学计量特征的影响

李思媛1(), 崔雨萱1, 孙宗玖1,2,3(), 刘慧霞1, 冶华薇1   

  1. 1.新疆农业大学草业学院,新疆 乌鲁木齐 830052
    2.西部干旱区草地资源与生态教育部重点实验室,新疆 乌鲁木齐 830052
    3.新疆草地资源与生态自治区重点实验室,新疆 乌鲁木齐 830052
  • 收稿日期:2022-06-20 修回日期:2022-09-21 出版日期:2023-06-20 发布日期:2023-04-21
  • 通讯作者: 孙宗玖
  • 作者简介:Corresponding author. E-mail: nmszj@21cn.com
    李思媛(1997-),女,新疆塔城人,在读硕士。E-mail: breezes09@163.com
  • 基金资助:
    国家自然科学基金项目(32060408);新疆维吾尔自治区自然科学基金(2020D01A60)

Effect of grazing exclusion on soil organic carbon and stoichiometry characteristics of soil microbial biomass in sagebrush desert

Si-yuan LI1(), Yu-xuan CUI1, Zong-jiu SUN1,2,3(), Hui-xia LIU1, Hua-wei YE1   

  1. 1.College of Grassland Science,Xinjiang Agricultural University,Urumqi 830052,China
    2.Key Laboratory of Grassland Resources and Ecology of Western Arid Region,Ministry of Education,Urumqi 830052,China
    3.Xinjiang Key Laboratory of Grassland Resources and Ecology,Urumqi 830052,China
  • Received:2022-06-20 Revised:2022-09-21 Online:2023-06-20 Published:2023-04-21
  • Contact: Zong-jiu SUN

摘要:

为了厘清封育过程中退化荒漠草地土壤微生物生物量生态化学计量学特征、土壤有机碳积累特征及其关系,对天山北坡新源县、博乐市、玛纳斯县、呼图壁县、奇台县封育4~7年的蒿类荒漠草地0~50 cm土层土壤有机碳(SOC)、土壤微生物生物量碳(MBC)、氮(MBN)、磷(MBP)含量及其化学计量比进行了分析,并用结构方程模型解析了SOC与土壤MBC、MBN、MBP及其化学计量比间的关系。结果表明:1)封育后0~50 cm土层蒿类荒漠草地SOC含量较对照显著降低15.52%(P<0.05),而土壤MBC、MBN、MBP、MBC/MBN、MBC/MBP、MBN/MBP总体变化不显著。2)SOC与MBC、MBN、MBP均呈显著正相关(P<0.01),与MBC/MBN、MBC/MBP呈负相关,且封育后SOC与MBN/MBP间的关系由显著正相关转为负相关(P<0.01)。3)结构方程分析表明,土壤MBC、MBN、MBP及其计量比对SOC积累的直接解释率为46%,且MBN对土壤有机碳的作用效应最强(P<0.001),封育降低了土壤MBC、MBN对土壤有机碳积累的影响,增加了土壤MBP的直接影响。总之,封育4~7年对蒿类荒漠草地土壤微生物生物量生态化学计量特征影响不显著,且MBN是影响土壤有机碳积累的主要因素。

关键词: 蒿类荒漠, 土壤有机碳, 土壤微生物生物量, 化学计量特征, 封育

Abstract:

This research aimed to clarify soil microbial biomass eco-stoichiometry characteristics in desert montane grassland in the years following grazing exclusion. Soil organic carbon accumulation and its relationship in degraded desert grassland to soil organic carbon (SOC), soil microbial biomass carbon (MBC), nitrogen (MBN), phosphorus (MBP)and their stoichiometric ratios were analyzed in the 0-50 cm soil layer of sagebrush desert grasslands from Xinyuan, Bole, Manasi, Hutubi and Qitai counties on the northern slopes of the Tianshan Mountains for 4-7 years following grazing exclusion. The relationships between soil organic carbon (SOC), soil MBC, MBN, MBP and their stoichiometric ratios were analyzed by structural equation modeling (SEM). It was found that the SOC content of sagebrush desert grassland in the 0-50 cm soil horizon after grazing exclusion was significantly reduced by 15.52% compared with the control (P<0.05), while the overall changes of soil MBC, MBN, MBP, MBC∶MBN, MBC∶MBP and MBN∶MBP were not significant. SOC was significantly positively correlated with MBC, MBN, and MBP (P<0.01), and negatively correlated with MBC∶MBN and MBC∶MBP, and the relationship between SOC and MBN∶MBP changed from significantly positive to negative after grazing exclusion (P<0.01). SEM showed that soil MBC, MBN, MBP and their stoichiometric ratios data directly explained 46% of data variation for SOC accumulation, and MBN had the strongest effect on soil organic carbon (P<0.001), while grazing exclusion reduced the effect of soil MBC and MBN on soil organic carbon accumulation and increased the direct effect of soil MBP. In conclusion, the effects of 4-7 years of grazing exclusion on soil microbial biomass eco-stoichiometry characteristics of sagebrush desert grassland were not significant, and MBN was the most influential determining factor for soil organic carbon accumulation.

Key words: sagebrush desert, soil organic carbon, soil microbial biomass, stoichiometric characteristics, grazing exclusion