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草业学报 ›› 2026, Vol. 35 ›› Issue (3): 43-51.DOI: 10.11686/cyxb2025177

• 研究论文 • 上一篇    下一篇

土壤碳饱和度对黄土高原温性草原凋落物分解及土壤碳固存的影响

蒋玉奇1(), 郭鑫2, 姜佳昌3, 刘兴明3, 梁春燕4, 文海燕1, 牛得草1, 李旭东1()   

  1. 1.草种创新与草地农业生态系统全国重点实验室,兰州大学草地农业科技学院,甘肃 兰州 730020
    2.甘肃省兰州生态环境监测中心,甘肃 兰州 730000
    3.甘肃省草原技术推广总站,甘肃 兰州 730010
    4.甘肃省兰草新生态科技有限公司,甘肃 兰州 730050
  • 收稿日期:2025-05-07 修回日期:2025-07-10 出版日期:2026-03-20 发布日期:2026-01-19
  • 通讯作者: 李旭东
  • 作者简介:Corresponding author. E-mail: lixudong@lzu.edu.cn
    蒋玉奇(2001-),男,山东泰安人,在读硕士。E-mail: jiangyq2023@lzu.edu.cn
  • 基金资助:
    甘肃省自然科学基金重点项目(22JR5RA400);甘肃省自然科学基金项目(22JR5RA464);2023年提前批中央财政林业改革发展资金草原科技支撑项目“河西走廊脆弱生态区草原生态健康评估”和甘肃省林业和草原局甘肃省草原监测评价科技支撑项目(〔2021〕794号)资助

Impact of grassland soil carbon saturation on litter decomposition and soil carbon sequestration

Yu-qi JIANG1(), Xin GUO2, Jia-chang JIANG3, Xing-ming LIU3, Chun-yan LIANG4, Hai-yan WEN1, De-cao NIU1, Xu-dong LI1()   

  1. 1.State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China
    2.Lanzhou Monitoring Center of Ecology and Environment of Gansu Province,Lanzhou 730000,China
    3.Gansu Grassland Technology Promotion Station,Lanzhou 730010,China
    4.Gansu Lancao New Ecological Technology Corporation,Lanzhou 730050,China
  • Received:2025-05-07 Revised:2025-07-10 Online:2026-03-20 Published:2026-01-19
  • Contact: Xu-dong LI

摘要:

植物凋落物是土壤有机碳(SOC)的重要来源,SOC的形成及其稳定性不仅与植物碳输入直接相关,同时也受到土壤碳饱和度的影响。本研究选取黄土高原温性草原优势物种长芒草的叶片和根系为凋落物材料,将其与不同碳饱和度的土壤(SOC含量分别为9.02,5.28和2.64 g·kg-1)在室内共同培养3年,通过分析不同碳饱和度条件下凋落物的分解速率以及全土和各粒径土壤团聚体中SOC的变化,以明确土壤碳饱和度对凋落物分解以及SOC固存的影响。结果表明:随着土壤碳饱和度的降低,土壤微生物量碳逐渐增加,凋落物分解速率显著升高,全土及各粒径团聚体中的新碳形成效率也逐渐升高,SOC含量显著增加。说明碳饱和度较低的土壤对外源有机碳具有更高的固存效率。在0.25~2.00 mm、0.053~0.250 mm和<0.053 mm这3个粒径土壤团聚体组分中,随着土壤碳饱和度的降低,凋落物碳分解后更多地向<0.053 mm的团聚体分配,进而有利于生成稳定性高的矿物结合态SOC。

关键词: 凋落物, 土壤碳饱和度, 土壤团聚体, 土壤碳稳定性

Abstract:

Plant litter is an important source of soil organic carbon (SOC). The formation and stability of SOC are not only directly related to plant carbon input but also affected by soil carbon saturation. In this study, leaves and roots of Stipa bungeana, a dominant species in the temperate grassland of the Loess Plateau, were selected as litter materials. They were co-cultured in the laboratory for 3 years with soils of different carbon saturation levels (with SOC contents of 9.02, 5.28, and 2.64 g·kg-1, respectively). The aim was to clarify the impact of soil carbon saturation on litter decomposition and SOC sequestration by analyzing the decomposition rate of litter and the changes in SOC in bulk soil and soil aggregates of various particle sizes under different carbon saturation conditions. The results showed that with decrease in soil carbon saturation, soil microbial biomass carbon gradually increased, while the litter decomposition rate significantly increased, the new carbon formation efficiency (NCE) in the bulk soil and the proportions of aggregates of all particle sizes also gradually increased, and the SOC content significantly increased. This indicates that soils with lower carbon saturation have a higher sequestration efficiency for exogenous organic carbon. Among the three soil aggregate fractions of decreasing size, 0.25-2.00 mm, 0.053-0.25 mm, and <0.053 mm, as soil carbon saturation decreased, more decomposed litter carbon was allocated to the <0.053 mm aggregates, which is conducive to the formation of mineral-associated organic carbon with high stability.

Key words: litter, soil carbon saturation, soil aggregates, soil carbon stability