Abstract:

In order to protect, develop and utilize plant resources on the Qinghai-Tibet Plateau and improve the ecological environment, 167 species, 43 families and 121 genera of psammophytes were found through the field investigation of psammophytes in 44 sample plots in the middle basin of Yarlung Zangbo River. Except for 1 species of Fungus, 2 species of Gymnosperms and 4 species of Ferns, Angiosperms are the main components, and dicotyledonous plants are the main groups of Angiosperms. There are 138 species of herbaceous plants, with perennial herbaceous plants as the main life type. Qushui County of Lhasa City is the main distribution area of psammophytes. The species similarity in each distribution area was low, and only 7.69% of the species with the similarity coefficient above 0.4 were found in the two districts. The vertical distribution showed an "intermediate expansion" altitude distribution trend, and most species were mainly distributed between 3501-4100 m; only 28.74% of the species distributed in two or more elevations. Psammophyte species in this area are relatively abundant, and their distribution varies greatly in different counties (districts) or altitude scales. This study can provide a scientific basis for the use of native plants to breed and cultivate excellent sand-fixing plants for the restoration of vegetation in the desertification land of Qinghai-Tibet Plateau.

Key words: middle basin of Yarlung Zangbo River, psammophytes, diversity, similarity, Qinghai-Tibet Plateau, ecological restoration, vegetation distribution