长江流域资源与环境 >> 2025, Vol. 34 >> Issue (3): 641-651.doi: 10.11870/cjlyzyyhj202503014

• 生态环境 • 上一篇    下一篇

三江源高寒湿地生长季甲烷通量变化及贡献源区影响研究

李甫1,2,周秉荣1,2,马文哲3 ,王力1   

  1. (1.青海省气象科学研究所, 青海 西宁 810001;2.青海省防灾减灾重点实验室, 青海 西宁 810001;3.中国气象科学研究院,北京 100081)
  • 出版日期:2025-03-20 发布日期:2025-03-20

Changes of Methane Flux and the Influence of Flux-Source Area during the Growing Season in Alpine Wetland of the Source of the Three Rivers

LI Fu1,2, ZHOU Bing-rong1,2, MA Wen-ze3, WANG Li1   

  1. (1. Institute of Qinghai Meteorological Science Research, Xi’ning 810001, China;2. Qinghai Key Laboratory of Disaster Preventing and Reducing, Xi’ning 810001, China;3.Chinese Academy of Meteorological Sciences, Beijing 100081,China)
  • Online:2025-03-20 Published:2025-03-20

摘要: 基于三江源隆宝湿地2021年4~9月的甲烷通量观测数据,分析了三江源中部高寒湿地甲烷通量的动态变化以及环境因子对甲烷通量的影响。隆宝湿地生长季以排放甲烷为主,甲烷通量的量级介于10-2~10-3μmol·m-2·s-1,日排放和月排放的最大值均出现在8月,其中日排放最大值为92.7 mg·m-2·d-1,月排放最大值为1 870 mg·m-2·mon-1。隆宝湿地的甲烷通量表现为贡献源区在北侧时较小,而南侧时较大,其最大值是最小值的4倍。而且贡献源区会对环境因子归因分析结果产生较大影响。对于高寒湿地而言,开展环境因子对甲烷通量的影响研究时,贡献源区也是一个需要考虑的因素。

Abstract: Based on the methane flux observation data of Longbao Wetland in the source area of the three rivers from April to September 2021, the dynamic changes of methane flux in the alpine wetland of the source area of the three rivers and the impact of environmental factors on the methane flux were analyzed. The vorticity observation instruments included the CSAT3A ultrasonic anemometer and Li 7 700 open circuit infrared gas analyzer. These instruments were installed at a height of 2 meters and operated at a frequency of 10 Hz. The software of Eddypro 7.0.6 was employed to calculate the primary methane flux data. Data points with a quality level of 2, recorded during precipitation periods, and obtained during nighttime with a friction wind speed (U*) below 0.15 m/s, were excluded from the analysis. Consequently, secondary methane flux data was obtained by applying these criteria. In order to identify and remove outliers in the secondary data, the Laida criterion was utilized to eliminate data points with magnitudes ranging from 101 to 102. Following the quality control procedures, a total of 3 839 valid methane flux data points were obtained for the Longbao Wetland site. Methane emissions in the Longbao wetland predominantly occurred during the growing season, with methane flux ranging from 10-2 to 10-3 μmol · m-2 · s-1. The maximum daily and monthly emissions occurred in August, reaching a peak of 92.7 mg · m-2 · d-1 and 1 870 mg · m-2 · mon-1, respectively. The Longbao Wetland demonstrated a differential methane flux pattern, with lower fluxes associated with the Flux-Source Area located on the north side, and higher fluxes observed on the south side. The maximum flux was four times greater than the minimum flux. The Flux-Source Area had a significant impact on the results of attribution analysis. By measuring the average methane flux at an interval of 0.1 Hpa in saturated water vapor pressure and an interval of 1 °C in temperature, a fitting model was established to relate these variables to the methane flux in the two contributing source regions. It was worth noting that the determination coefficients and parameters of the model exhibited considerable differences when the contributing source regions were altered. For alpine wetlands ecosystems, the Flux-Source Area was also a factor that needed to be incorporated in the relationship between environmental factors and methane flux.

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