If movement of people try banned by plateaus which can be detrimental to An excellent

cerana survival, populations in adjacent valleys are more likely to undergo genetic differentiation as a result of the blockage of gene flow. This study indeed showed genetic differentiation between A. cerana populations in different valleys of the Qinghai-Tibet Plateau. Based on the conducted PCoA and DAPC, A. cerana in different valleys showed obvious differentiation. Furthermore, the FST of microsatellites and mitochondria ranged from 0.04–0.29 to 0.06–0.76, respectively. According to Wright (Wright, 1978) and compared to other A. cerana research (Xu et al., 2013a; Yin and Ji, 2013), these results indicate population genetic differentiation. The highest reported elevation for a A. cerana population in the literature is 3250 m (Hepburn et al., 2001; Yang, 2001; Radloff et al., 2005). The observations of A. cerana at 3,040 m reported here are consistent with previously reported observations (Zhu et al., 2017). Based on this information, it could be inferred that the upper limit of the hospitable zone for A. cerana does not exceed 3,500 m. The valleys that were chosen in this study are separated by mountains with elevations > 4,000 m, such as the Boshula and Taniantaweng Mountains (Liu et al., 2016; Yang et al., 2016). Two main environmental characteristics are specific for this area. The first is that the area lacks vegetation, and is mostly covered by bare rock. The second is the presence of plateau meadows.