草地学报 ›› 2026, Vol. 34 ›› Issue (6): 1976-1989.DOI: 10.11733/j.issn.1007-0435.2026.06.002

• 研究论文 • 上一篇    

冻融交替加速冰缘带垫状植被生态系统氮素气态损失

张永智1, 陈哲1,2,3, 陈季贵4, 马瑷珲1, 陈裕1, 唐遵严1, 王世雄1,2,3, 关晋宏1,2,3, 王文颖1,2,3, 周华坤5, 谢惠春1,2,3, 郭志英4, 金艳霞1, 云世明1   

  1. 1. 青海师范大学生命科学学院/青藏高原地表过程与生态保育教育部重点实验室, 青海 西宁 810016;
    2. 高原科学与可持续发展研究院, 青海 西宁 810016;
    3. 青海省青藏高原生物多样性形成机制与综合利用重点 实验室, 青海 西宁 810016;
    4. 青海省海北州门源县草原站, 青海 海北州 810300;
    5. 中国科学院西北高原生物研究所青海省寒区恢复生态学重点实验室, 青海 西宁 810008
  • 收稿日期:2025-11-23 修回日期:2025-12-31 发布日期:2026-06-02
  • 通讯作者: 陈哲,E-mail:chenzhe@qhnu.edu.cn
  • 作者简介:张永智(1999-),男,汉族,甘肃武威人,硕士研究生,主要从事高寒草地生态系统生态学研究,E-mail:1061611658@qq.com
  • 基金资助:
    青海省自然科学基金(2024-ZJ-707);国家自然科学基金(32260288);国家重点研发计划(2023YFF1304300)资助

Alternating Freeze-Thaw Accelerates the Gaseous Loss of Nitrogen in the Pad-like Vegetation Ecosystem of the Periglacial Zone

ZHANG Yong-zhi1, CHEN Zhe1,2,3, CHEN Ji-gui4, MA Ai-hui1, CHEN Yu1, TANG Zun-yan1, WANG Shi-xiong1,2,3, GUAN Jin-hong1,2,3, WANG Wen-ying1,2,3, ZHOU Hua-kun5, XIE Hui-chun1,2,3, GUO Zhi-ying4, JIN Yan-xia1, YUN Shi-ming1   

  1. 1. College of Life Sciences/Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining, Qinghai Province 810016, China;
    2. Academy of Plateau Science and Sustainability, Xining, Qinghai Province 810016, China;
    3. Qinghai Key Laboratory of Biodiversity Formation Mechanism and Comprehensive Utilization of the Qinghai-Tibetan Plateau, Xining, Qinghai Province 810016, China;
    4. Menyuan County's Grassland Station, Haibei, Qinghai Province 810300, China;
    5. Northwest Institute of Plateau Biology, Chinese Academy of Sciences/Qinghai Provincial Key Laboratory of Restoration Ecology for Cold Regions, Xining, Qinghai Province 810008, China
  • Received:2025-11-23 Revised:2025-12-31 Published:2026-06-02

摘要: 为探究季节性冻融是否促进流石滩垫状植被生态系统氧化亚氮(N2O)排放,并加速氮素气态损失,本研究以祁连山东部岗什卡雪峰海拔4000~4400 m囊种草(Thylacospermum caespitosum)垫状植被为研究对象,连续两年监测土壤(0~30 cm)温湿度、养分动态特征及N2O通量。结果表明:土壤全年经历约70次昼夜冻融循环,主要分布在四个时期:不稳定融化期(25次)、稳定融化期、不稳定冻结期(45次)、稳定冻结期。海拔每升高100 m,土壤冻融起止时间平均推迟或提前3.88天。不稳定融化期(持续时间仅占全年5.5%~6.8%)N2O排放最显著,累积排放量(225.97 g·hm-2)占全年35.88%,最大排放速率达24.52 μg·m-2·h-1,平均通量(13.63 μg·m-2·h-1)是年均值的1.39倍,除稳定融化期外的非生长季N2O累积排放量总占比高达74.09%。排放受土壤水热、pH值主导,底物匮乏致生产量偏低。气候变暖下,冻融驱动冰缘带N2O氮素气态损失加剧,需深入研究水热条件与氮转化机制。

关键词: 气候变化, 高山冰缘带, 垫状植被, 冻融作用, 氧化亚氮

Abstract: To investigate whether seasonal freeze-thaw promotes the emission of nitrous oxide (N2O) and accelerates the gaseous loss of nitrogen in the talus plateau vegetation ecosystem, this study focused on the grassland (Thylacospermum caespitosum) pad vegetation at an altitude of 4000-4400 m on the Gangshigacha snow peak in the eastern part of the Qilian Mountains. The soil (0-30 cm) temperature, humidity, nutrient dynamic characteristics, and N2O flux were monitored continuously for two years. The results showed that the soil experienced approximately 70 daily freeze-thaw cycles throughout the year, divided into four periods: unstable thawing period (25 times), stable thawing period, unstable freezing period (45 times), and stable freezing period. For every 100-meter increase in altitude, the average start and end time of soil freeze-thaw was delayed or advanced by 3.88 days. The N2O emission was the most significant during the unstable thawing period (accounting for only 5.5%-6.8% of the entire year), with a cumulative emission (225.97 g·hm-2) accounting for 35.88% of the annual total, a maximum emission rate of 24.52 μg·m-2·h-1, an average flux of 13.63 μg·m-2·h-1, which was 1.39 times the annual average, and the cumulative emission during the non-growing seasons (excluding the stable thawing period) accounted for as high as 74.09%. The emission was dominated by soil water and heat, pH, and substrate scarcity, leading to low production. Under climate warming, the freeze-thaw driven nitrogen gas loss of N2O in the ice margin zone intensified, and further research on the water and heat conditions and nitrogen transformation mechanism is needed.

Key words: Climate change, Alpine periglacial zone, Cushion vegetation, Freeze-thaw action, Nitrous oxide

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