Arid regions, by definition, receive little precipitation (<25 cm of rain per year). They occupy about 35% of the Earth's land surface (Tchakerian, 2015). The Asian interior arid zone is the largest desert landform system in the Northern Hemisphere. In China, the arid region is concentrated in the northwest, including Xinjiang, the western region of Inner Mongolia, and Gansu, Ningxia and Qinghai provinces, with about 2.5 million km 2 or one-quarter of the entire Chinese territory (Wang et al., 2015). Northwest China is one of the driest regions in the world at this latitude. Most of the region has a temperate continental climate with low precipitation and a high drought frequency. It covers a climate gradient ranging from arid to hyperarid conditions with various desert habitats, including