**5. Conclusions**

This study applied multiple statistical methods and long-time series remote sensing data to determine the spatial heterogeneity and controls of autumn phenology on the Qinghai-Tibetan Plateau. The results are summarized as follows. (1) EOS turning points exhibit notable spatial heterogeneities. (2) The climatic controls of the EOS before and after the turning points varied in different subregions on the Qinghai-Tibetan Plateau. (3) Changes in the turning points are controlled by the joint effects of climate and human activities (grazing and economic development). This study is the first to demonstrate the spatial heterogeneity of turning points at a pixel scale and discuss their controls on the Qinghai-Tibetan Plateau, which is useful for exploring the mechanism of EOS changes and developing regional ecosystem conservation measures.

**Author Contributions:** Conceptualization, Y.Y. and N.Q.; methodology, N.Q.; validation, N.Q., J.Z., X.W. and L.K.; writing—original draft preparation, Y.Y. and N.Q.; writing—review and editing, N.M., Z.L., B.W., J.M. and R.L.; project administration, H.Z.; funding acquisition, H.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by The Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (Grant No. 2019QZKK0307), the National Natural Science Foundation of China (41925005, 41701051, and 41801181) and Special Program of Research Center for Eco-environmental Sciences, CAS (RCEES-TDZ-2021-11).

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The GIMMS 3g NDVI data presented in this study are openly available at the National Qinghai-Tibetan Plateau Data Center at [http://poles.tpdc.ac.cn/en/data/9775f2b4 -7370-4e5e-a537-3482c9a83d88/. Accessed on 1 May 2021]. The climate data were downloaded from A Big Earth Data Platform for Three Poles with a spatial resolution of 0.1◦ and temporal resolution of 3h[http://poles.tpdc.ac.cn/zh-hans/data/7a35329c-c53f-4267-aa07-e0037d913a21/. Accessed on 1 May 2021].

**Conflicts of Interest:** The authors declare no conflict of interest.
