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草业学报 ›› 2026, Vol. 35 ›› Issue (5): 48-60.DOI: 10.11686/cyxb2025241

• 研究论文 • 上一篇    下一篇

降水变化对荒漠草原生态系统碳氮储量及固持速率的影响

杨雪琴1(), 李建平1,2,3(), 陈婧1, 连佳丽1, 韩翠1, 罗叙1, 赵莹1   

  1. 1.宁夏大学林业与草业学院,宁夏 银川 750021
    2.盐池北部荒漠草原宁夏野外科学观测研究站,宁夏 吴忠 751500
    3.宁夏圣友德实业有限公司,宁夏 灵武 751400
  • 收稿日期:2025-06-19 修回日期:2025-08-19 出版日期:2026-05-20 发布日期:2026-03-11
  • 通讯作者: 李建平
  • 作者简介:Corresponding author. E-mail: lijianpingsas@nxu.edu.cn
    杨雪琴(1998-),女,宁夏固原人,在读硕士。E-mail: 18295643570@163.com
  • 基金资助:
    宁夏自然科学基金项目(2023AAC03092);国家自然科学基金项目(32160336)

The impact of precipitation changes on carbon and nitrogen storage and retention rates in desert steppe ecosystems

Xue-qin YANG1(), Jian-ping LI1,2,3(), Jing CHEN1, Jia-li LIAN1, Cui HAN1, Xu LUO1, Ying ZHAO1   

  1. 1.School of Forestry and Grassland Science,Ningxia University,Yinchuan 750021,China
    2.Northern Yanchi Desert Steppe Observation and Research Station of Ningxia,Wuzhong 751500,China
    3.Ningxia Shengyoude Industrial Co. ,Ltd. ,Lingwu 751400,China
  • Received:2025-06-19 Revised:2025-08-19 Online:2026-05-20 Published:2026-03-11
  • Contact: Jian-ping LI

摘要:

作为陆地生态系统碳氮汇的重要贡献者,草地生态系统在调节全球碳氮源、汇及其循环过程中具有重要作用。本研究以毛乌素沙地南缘宁夏盐池县温性荒漠草原为对象,采用遮雨棚技术和人工补水措施,模拟5个水平的降水梯度,分别为自然降水量的33%、66%、100%、133%和166%(记为R33、R66、CK、R133、R166),系统研究了2018-2024年不同降水梯度下植被-土壤碳氮储量及固持速率的变化规律。经过6年降水控制模拟试验,结果表明:1)表层(0~10 cm)土壤碳氮储量受降水变化更敏感,降水减少导致表层土壤碳氮储量随处理年限增加呈下降趋势;降水增加使表层土壤碳氮储量呈上升趋势;2)降水增加时,植被碳氮储量随处理年限的增加显著上升;3)增水处理下,植被碳储量占草地生态系统碳储量的比重随时间增加呈上升趋势,2024年达到最大占比;随着降水量的减少和处理年限的增加,草地生态系统碳氮流失加剧,降水增加使草地生态系统碳氮固持速率呈上升趋势。因此,降水增加有助于植被-土壤生态系统碳氮储量增加及固持速率提高,降水减少导致碳氮流失加剧,研究结果为深入理解草地生态系统碳氮循环过程中的关键环节对降水变化的响应规律提供了参考。

关键词: 荒漠草原, 降水梯度, 碳、氮储量, 碳、氮固持速率

Abstract:

As an important contributor to carbon and nitrogen sinks in terrestrial ecosystems, grassland ecosystems play a crucial role in regulating global carbon and nitrogen sources, sinks, and cycling processes. This ongoing experiment is located on temperate desert grassland in Yanchi County, Ningxia, on the southern edge of the Mu Us Desert. The experiment treatments simulate five levels of precipitation using rain shelters and manual water replenishment (33%, 66%, 100%, 133%, and 166% of natural precipitation, coded as R33R66, CK,R133R166, respectively). Here we report changes in vegetation, soil carbon and nitrogen storage, and retention rates from 2018 to 2024 under the different precipitation regimes. After this six year period of precipitation control: 1) The carbon and nitrogen storage of surface soil (0-10 cm) has responded more than at depth to changes in precipitation; decreased precipitation has led to a decrease in surface soil carbon and nitrogen storage with this effect increasing with the number of years. Conversely, increased precipitation has led to increased surface soil carbon and nitrogen storage. 2) Increased precipitation has led to increased, vegetation carbon and nitrogen storage and this effect has significantly increased over time. 3) Under water addition treatment, the proportion of vegetation carbon storage in the total carbon storage of the grassland ecosystem shows an upward trend over time, peaking in 2024; while the opposite (depletion) has occurred in the 33% and 66% precipitation regimes. Therefore, an increase in precipitation contributes to an increase in carbon and nitrogen storage and sequestration rates in vegetation and soil components of this ecosystem, while a decrease in precipitation exacerbates carbon and nitrogen loss. These research results provide quantitative data and enhance understanding of the response patterns of key links in the carbon and nitrogen cycling process of steppe ecosystems in response to precipitation change.

Key words: desert steppe, precipitation gradient, carbon and nitrogen storage, carbon and nitrogen sequestration rate