2.1. Site description
This study was conducted in Ganchaitan, close to Haibei station (101°19′E, 37°37′N, 3335 m), and included two neighboring sites (i.e., shrubs site and grassland site, the distance between them was 460 m) in the northeastern Qinghai-Tibet Plateau, located in Qinghai Province, China, (Figure 1). The region is in a semiarid, cold, high-altitude climate zone (Dai et al., 2019b). The mean annual precipitation is approximately 562 mm. Almost 80% of the annual precipitation falls during the growing season (i.e., from May to September). The mean annual air temperature is approximately -1.7℃, with the maximum temperature occurring in July (9.8 ℃) and the minimum temperature occurring in January (-14.80℃) (Dai, et al., 2021). The soil type in the study area was classified as Mollic Gryic Cambisols based on the classification of soil systems in China (Liu et al., 2018). Vegetation characteristics of the sampling sites were investigated and shown in Table 1.
Table1 Vegetation characteristics of the sampling sites.