在国家“碳达峰、碳中和”战略背景下，资源枯竭型城市的生态修复正成为固碳增汇的重要途经，利用长时间序列观测数据开展固碳增汇能力定量评价，将为设计资源枯竭型城市生态修复方式提供有价值的参考。以我国东部典型资源枯竭转型城市徐州为研究区域，通过“涡度相关法”和“卫星遥感”2种方式观测分析了总初级生产力(Gross Primary Productivity，GPP)的时空变化特征。结果表明：① 在生长季植被生长旺盛的时候，MODIS卫星遥感对GPP存在低估，是由于光能利用率模型将同种植被的最大光能利用率设为定值，不能体现植被生长状态的影响，从而增加了估算光能利用率的不确定性。但MODIS GPP与涡度相关通量塔实测GPP数据变化趋势一致，有较强的相关性(R2=0.587，P=0)，因此MODIS GPP数据可用于徐州矿区生态修复前后GPP变化特征分析。② 2005—2011年，徐州煤矿开采对徐州矿区生态环境破坏严重，固碳能力持续减弱，2011年后徐州地区采取生态修复措施，GPP明显升高，到2015年GPP达到最高值(0.878 kgC/(m2·a))，2016—2020年GPP变化趋于稳定(0.85 kgC/(m2·a)左右)。③ 徐州采取的矿区关闭、煤矸石回填、生态公园建设等一系列生态修复措施，提高了原有矿区的固碳增汇能力，形成了自稳定生态系统，且未来仍有改善的趋势，证明对煤炭资源枯竭型城市进行生态修复可以在5～10 a内有效改善当地生态环境，快速提升当地的植被固碳能力，为其他煤炭资源枯竭型城市的生态修复提供参考。

In the context of the national strategy of “carbon peak and carbon neutrality”, ecological restoration in resource-depleted cities is becoming an important way to carbon sequestration and sinks. The quantitative evaluation of carbon sequestration and sink capacity using long time series observation data will provide valuable references for designing ecological restoration methods in resource-depleted cities. Taking Xuzhou, a typical resource-depleted transformation city in eastern China, as the research area, the temporal and spatial variation characteristics of Gross Primary Productivity (GPP) were observed and analyzed by “Eddy Covariance” and “satellite remote sensing”. The results show that: ① MODIS satellite remote sensing underestimates GPP during the growing season when vegetation is actively growing, because the Light Use Efficiency model sets the maximum Light Use Efficiency of the same vegetation as a constant value, which does not reflect the influence of vegetation growth state, thus increasing the uncertainty of estimating Light Use Efficiency. However, the MODIS GPP and the GPP measured by Eddy Covariance flux tower have the same trend and strong correlation (R2=0.587, P=0), so the MODIS GPP data can be used for the analysis of the GPP change characteristics before and after ecological restoration in the Xuzhou mining area. ② From 2005 to 2011, the coal mining severely damaged the ecological environment in the Xuzhou mining area, and the carbon sequestration capacity continued to weaken. After 2011, the Xuzhou area adopted ecological restoration measures, and the GPP increased significantly and reached the highest value in 2015 (0.878 kgC/(m2·a)), and the change of GPP tended to be stabilized between 2016 and 2020 (0.85 kgC/(m2·a) or so). ③ A series of ecological restoration measures such as mine closure, coal gangue backfill and ecological park construction adopted by Xuzhou have improved the carbon sequestration and sink capacity of the original mine area and formed a self-stabilizing ecosystem, and there is still a trend of improvement in the future, proving that the ecological restoration of coal depleted cities can effectively improve the local ecological environment and rapidly enhance the local carbon sequestration capacity of vegetation within 5 to 10 years, providing a reference for the ecological restoration of other coal depleted cities.