Acknowledgments
This research was financially supported by the National Natural Sciences Foundation of China (No. U1603105 and No. 41730638) and the Key Research Project of Frontier Sciences, CAS (No. QYZDJ-SSW-DQC014). We thank the staff at the Fukang Station of Desert Ecology for their excellent assistance. We would like to thank Dr.Larry Bowman at Yale University for his assistance with English language and grammatical editing.