青海省陆地生态系统碳汇潜力及空间特征  

The Assessment and Spatial Pattern of Potential Terrestrial Ecosystem Carbon Sink Strengths in Qinghai Province

作　　者：张法伟[1,2] 仪律北 李杰霞 王军邦[4] 李英年[1,2] 周华坤[1,2,5] Zhang Fawei;Yi Lubei;Li Jiexia;Wang Junbang;Li Yingnian;Zhou Huakun(Institute of Sanjiangyuan National Park,Chinese Academy of Sciences,Xining 810001,China;Key Laboratory of Adaptation and Evolution of Plateau Biota,Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810001,China;Forestry Carbon Sequestration Service Center,Qinghai Forestry and Grassland Bureau,Xining 810008,China;Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100105,China;Qinghai Provincial Key Laboratory of Restoration Ecology in Cold Region,Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810001,China)

机构地区：[1]中国科学院三江源国家公园研究院,西宁810001 [2]中国科学院西北高原生物研究所高原生物适应与进化重点实验室,西宁810001 [3]青海省林业和草原局林业碳汇服务中心,西宁810008 [4]中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室,北京100105 [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,西宁810001

出　　处：《青海科技》2023年第1期31-36,共6页Qinghai Science and Technology

基　　金：国家林业和草原局经济发展研究中心业务委托(JYFL-2021-00020);中国科学院-青海省人民政府三江源国家公园联合研究专项(LHZX-2020-07);青海省自然科学基金创新团队项目(2021-ZJ-902)。

摘　　要：青藏高原是中国陆地生态系统的一个重要的碳汇功能区,但其碳汇强度及潜力的估算存在很大的差异,不利于区域碳中和目标的实现。基于涡度相关技术观测的原生高寒草地生态系统CO_(2)通量的40个站点年数据,结合2000年~2018年的年均气温、年均降水和年最大归一化植被指数(NDVIm)等因子,构建增强回归树模型以研究青海省陆地生态系统碳汇潜力及空间特征。结果表明增强回归树模型能够较好地模拟原生高寒草地碳汇强度的时空变异(R2=0.61),碳汇强度的观测值与模拟值的均方根误差和平均绝对误差分别为33.78 g C/m^(2)和26.63 g C/m^(2)。年均气温和NDVIm是高寒草地碳汇强度时空变异的主要影响因子,二者的相对贡献分别为48.6%和39.0%。青海省陆地生态系统每年的碳汇潜力平均为44.82±22.57 g C/m^(2)(平均值±标准差),高值区集中在海北州的中部及黄南州、果洛州和玉树州的东南部,低值区分布在海西州、海南州和海东市。青海省陆地生态系统每年的碳汇潜力总和为16.60 Mt C,其中高寒草甸和高寒草原分别为11.48 Mt C和3.13 Mt C,是青海省碳汇功能维持和提升的重点保育对象。研究结果可为青海省陆地生态系统的功能评估及率先实现碳中和目标提供数据支撑。The Qinghai-Tibetan Plateau plays an important role in China’s terrestrial ecosystem carbon sequestration,but there are remarkable differences in estimating carbon sink strengths and potentials,which have substantially impacted the achievement of regional“carbon neutrality”goal.Based on 40 site-year CO_(2)flux data of healthy alpine grassland ecosystems observed by the eddy covariance techniques,combined with the annual air temperature,precipitation,and maximum normalized difference vegetation index(NDVIm)from 2000 to 2018,the boosted regression trees model of the potential carbon sink capacity of terrestrial ecosystems were calibrated to explore its spatial pattern in Qinghai Province.The results showed that the boosted regression trees model could better simulate the spatiotemporal variations of carbon sink strengths of alpine grassland(R~2=0.61),and the root mean square error and mean absolute error of observed values and predicted values of carbon sink strengths are 33.78 g C/m^(2)and 26.63 g C/m^(2)respectively.Annual air temperature and NDVImare the main drivers and accounted 87.6%of the spatiotemporal variations of the carbon sink strengths of alpine grasslands.The potential annual carbon sink capacity of Qinghai’s terrestrial ecosystem was estimated 44.82±22.57 g C/m^(2)(mean±standard deviation).The high values were concentrated in the middle of Haibei Prefecture and the southeast of Huangnan Prefecture,Guoluo Prefecture and Yushu Prefecture,while the low values were distributed in Haixi Prefecture,Hainan Prefecture and Haidong City.The potential annual carbon sink capacity of Qinghai’s terrestrial ecosystem was accumulated 16.60 Mt,in which the alpine meadows and alpine grasslands were 11.48 Mt C and 3.13 Mt C respectively,which are the key conservation objects for the maintenance and promotion of carbon sink function in Qinghai Province.The findings can provide data support for the functional assessment of the terrestrial ecosystem and the first achievement of the carbon neutrality goal in Q

关 键 词：高寒草地 碳汇强度 空间特征 增强回归树模型 碳中和 

分 类 号：X171.1[环境科学与工程—环境科学]