1. College of Life Sciences, Shaanxi Normal University, Xi’an 710119, China
2. School of Environment and Resources, Taiyuan University of Science and Technology, Taiyuan 030024, China
3. Research Center for UAV Remote Sensing, Shaanxi Normal University, Xi’an 710119, China
4. Changqing Teaching & Research Base of Ecology, Shaanxi Normal University, Xi’an 710119, China