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草业学报 ›› 2026, Vol. 35 ›› Issue (8): 14-21.DOI: 10.11686/cyxb2025420

• 研究论文 • 上一篇    下一篇

土壤水分对黄土高原温性草原凋落物分解及土壤有机碳形成的影响

罗欢1(), 蒋玉奇2, 牛得草2, 郭丁2, 李旭东2()   

  1. 1.甘肃农业职业技术学院,甘肃 兰州 730030
    2.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
  • 收稿日期:2025-10-18 修回日期:2025-11-12 出版日期:2026-08-20 发布日期:2026-06-22
  • 通讯作者: 李旭东
  • 作者简介:Corresponding author. E-mail: lixudong@lzu.edu.cn
    罗欢(1982-),女,甘肃两当人,硕士。E-mail: 42442746@qq.com
  • 基金资助:
    甘肃省科技计划(22JR5RA400);甘肃省林业和草原局甘肃省草原监测评价科技支撑项目(HT-GSZYTC-ZCJC-21009);甘肃省林业和草原局甘肃省草原监测评价项目(GSZYTC-ZCJC-21010)

The impact of soil moisture on litter decomposition and soil organic carbon deposition in the temperate grasslands of the Loess Plateau

Huan LUO1(), Yu-qi JIANG2, De-cao NIU2, Ding GUO2, Xu-dong LI2()   

  1. 1.Gansu Vocational College of Agriculture,Lanzhou 730030,China
    2.State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China
  • Received:2025-10-18 Revised:2025-11-12 Online:2026-08-20 Published:2026-06-22
  • Contact: Xu-dong LI

摘要:

凋落物分解是影响土壤有机碳(SOC)形成的重要过程,而土壤水分条件会对这一过程产生重要影响。研究土壤水分变化对草地凋落物分解及其对土壤有机碳形成的影响,有助于阐明气候变化背景下土壤碳库的动态变化及其稳定机制。本研究以黄土高原温性草原优势物种长芒草为对象,通过将其叶片(SL)和根系(SR)在不同水分条件下[W1:土壤年平均含水量(质量含水量为7.16%);W2:土壤田间持水量的50%(质量含水量为23.55%)]与土壤共同培养3年,分析不同水分条件下凋落物的分解特征以及土壤有机碳和团聚体有机碳的变化。结果表明:与W1相比,W2条件下SL和SR处理的土壤微生物量碳显著增加了25.2%和40.7%,进而显著提高了凋落物的分解速率,同时也显著增加了SOC含量(P<0.05)。另外,土壤水分的增加显著提高了<0.053 mm团聚体的新碳形成效率,SL和SR处理在W2条件下的新碳形成效率较W1分别显著增加6.5%和8.0%(P<0.05)。说明在半干旱区温性草原,土壤水分的增加可促进凋落物的分解,并使凋落物碳分解后更多地向<0.053 mm团聚体中分配,进而促进了矿质结合态有机碳的形成。

关键词: 土壤水分, 凋落物, 分解速率, 土壤团聚体, 碳稳定性

Abstract:

Litter decomposition is a key process affecting the formation of soil organic carbon (SOC), and soil moisture conditions exert a significant influence on this process. Investigating the effects of soil moisture changes on grassland litter decomposition and its role in soil organic carbon formation is conducive to clarifying the dynamic changes in soil carbon pools and their stabilization mechanisms in the context of climate change. In this study, Stipa bungeana, a dominant species in the temperate grasslands of the Loess Plateau-was selected for study. S. bungeana leaves (SL) and S. bungeana roots (SR) were co-cultured with soil for 3 years under different moisture conditions [W1: annual average soil moisture content (gravimetric water content of 7.16%); W2: 50% of soil field capacity (gravimetric water content of 23.55%)]. The decomposition characteristics of litter and the changes in soil organic carbon and organic carbon in soil aggregates under the different moisture conditions were analyzed. It was found that, compared with W1, the soil microbial biomass carbon in the SL and SR treatments in the W2 treatment increased (P<0.05) by 25.2% and 40.7%, respectively. The W2 treatment not only significantly accelerated the litter decomposition rate but also significantly increased the SOC content (P<0.05). In addition,adequate moisture conditions facilitate the formation of mineral-associated organic carbon in soils of semi-arid regions. Specifically, in the W2 treatment, the new carbon formation efficiency of the SL and SR treatments increased significantly by 6.5% and 8.0% respectively compared with W1P<0.05). These findings indicate that in the temperate grasslands of semi-arid regions, an increase in soil moisture can not only promote litter decomposition, but also promote a greater allocation of litter carbon to soil aggregates <0.053 mm, thereby facilitating the formation of mineral-associated organic carbon.

Key words: soil moisture, litter, decomposition rate, soil aggregates, carbon stability