Acknowledgements

Funding was provided by the State Key Research Development Program of China (Grant No. 2016YFC0501803 and 2016YFC0501802), the Second Tibetan Plateau Scientific Expedition and Research (Grant No.2019QZKK0405), and the Open Project of the Qinghai Provincial Key Laboratory of Restoration Ecology in Cold Area(2020-KF-05). We gratefully acknowledge the Beijing Municipal Education Commission for their financial support through Innovative Transdisciplinary Program ”Ecological Restoration Engineering”.