This work was supported by the National Natural Science Foundation of China [grant number 41871223], the 2023 Graduate Innovation Fund Project of China University of Geosciences, Beijing [grant number ZD2023YC052], the Natural Science Foundation of Hunan Province (2021JJ40012), and the Scientific Research Fund of Hunan Provincial Education Department (20A072). We thank the Nanjing University and NASA EOSDIS Land Processes DAAC for free availing dataset of NEP data and land cover data, respectively. We would like to acknowledge the Editage institution ( www.editage.com ) for language modification.