Spatio-Temporal Patterns of Ecosystem Services Provided by Urban Green Spaces and Their Equity along Urban-Rural Gradients in the Xi'an Metropolitan Area, China. - Lixian Peng; Liwei Zhang; Xupu Li; Pengtao Wang; Wudong Zhao; Zhuangzhuang Wang; Lei Jiao 006; Hao Wang (Remote. Sens., 2022)