祁连山典型亚高山草甸生态系统碳交换的季节动态  

Seasonal dynamics of carbon exchange in a typical subalpine meadow ecosystem of the Qilian Mountains

作　　者：高天胜 付宇鹏 陈生云 戎战磊 赵传燕 GAO Tiansheng;FU Yupeng;CHEN Shengyun;RONG Zhanlei;ZHAO Chuanyan(College of Geography Science,Qinghai Normal University,Xi’ning 810008,Qinghai,China;Xining Center of Natural Resources Comprehensive Survey,China Geological Survey,Xi’ning 810000,Qinghai,China;Observation Station of Subalpine Ecology Systems in the middle Qilian Mountains,Zhangye 734000,Gansu,China;Cryosphere and Eco-Environment Research Station of Shule River Headwaters/State Key Laboratory of Cryospheric Science/Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;College of Grassland Agriculture,Northwest A&F University,Yangling 712100,Shaanxi,China;College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,Gansu,China)

机构地区：[1]青海师范大学地理科学学院,青海西宁810008 [2]中国地质调查局西宁自然资源综合调查中心,青海西宁810000 [3]祁连山中部亚高山生态系统野外科学观测研究站,甘肃张掖734000 [4]中国科学院西北生态环境资源研究院/冰冻圈科学国家重点实验室/疏勒河源冰冻圈与生态环境综合监测研究站,甘肃兰州730000 [5]西北农林科技大学草业与草原学院,陕西杨凌712100 [6]兰州大学草地农业科技学院,甘肃兰州730020

出　　处：《草业科学》2025年第3期537-548,共12页Pratacultural Science

基　　金：国家自然科学基金项目(41871064);中国地质调查局地质调查项目(DD20220883);青海省重点研发与转化计划项目(2020-SF-146)。

摘　　要：分布在海拔2500~3800m的亚高山草甸是祁连山区分布面积最大的陆地生态系统,为区域碳固持发挥了重要作用。然而,对于亚高山草甸生态系统碳交换的季节动态特征至今缺乏较系统的研究。本研究利用2021年全年的涡度相关系统连续监测数据分析了祁连山中部天涝池小流域典型亚高山草甸生态系统碳组分通量的变化特征。结果表明:1)亚高山草甸净生态系统碳交换(NEE)平均通量呈单谷曲线,生态系统呼吸(Reco)、生态系统总初级生产力(GPP)平均通量变化均呈单峰曲线,且均在11:00-13:00达到碳吸收峰值,夜晚则是碳排放;2)逐步回归分析表明,在日尺度上NEE受5 cm土壤温度(Ts)控制,Reco与空气温度(Ta)、土壤温度和5 cm土壤含水量(SWC)极显著相关(P<0.01),GPP与Ts、SWC极显著相关;3)在月尺度上,Reco、NEE、GPP均与叶面积指数(LAI)表现出显著的相关关系(P<0.01),随着生长季开始,NEE、Reco、GPP逐渐增大,随着生长季结束,各通量组分迅速减小。年NEE为-267.9 g·(m^(2)·a)^(-1),碳汇作用较强。研究结果为祁连山北麓区域围封禁牧的亚高山草甸生态系统固碳服务评估提供了科学依据。The alpine grassland ecosystem is the largest terrestrial ecosystem type in the Qilian Mountains region and has a significant impact on the regional carbon cycle.This study analyzed the variation characteristics of CO_(2) flux components in the subalpine meadow ecosystem in the middle of the Qilian Mountains based on continuous observational data from an eddy covariance system and meteorological data from the year 2021.Correlation and regression analysis were performed to explore the relationships between the flux components and environmental factors.The results showed that:1)the ecosystem respiration(Reco),the net ecosystem carbon exchange(NEE),and the gross primary productivity(GPP)of the subalpine meadow all displayed unimodal curves in their average half-hourly flux changes throughout the year.On a daily scale,the peak carbon absorption of the ecosystem occurred during 11:00-13:00,whereas negative carbon absorption(i.e.,carbon emission)occurred at nighttime;2)Stepwise regression analysis showed that on a daily scale,NEE was controlled by the soil temperature(Ts)at a 5 cm soil depth,Reco showed a significant relationship with air temperature,soil temperature,and soil moisture content(SWC)at a 5 cm soil depth(P<0.01),whereas GPP significantly correlated(P<0.01)with Ts and SWC;3)On a monthly scale,Reco,NEE,and GPP all demonstrated a significant relationship with leaf area index(LAI),with distinct seasonal variations.The annual NEE of the subalpine meadow ecosystem was-267.9 g·(m^(2)·a)−1,indicating a strong carbon sink.The results provide a scientific basis for the assessment of carbon sequestration services in the subalpine meadow ecosystems of Qilian Mountains.

关 键 词：祁连山 亚高山草甸 涡度相关 生态系统呼吸 总初级生产力 净生态系统碳交换 碳汇 

分 类 号：Q94[生物学—植物学]