Variation of Soil Carbon, Nitrogen and Phosphorus and Ecological Stoichiometric Characteristics During Land Degradation in Coal Mining Subsidence AreaYangnan Guo, Xin Zhang, Jianhong Chang and Xiaolong WangE3S Web of Conf., 406 (2023) 01043DOI: https://doi.org/10.1051/e3sconf/202340601043