Floristic characteristics of seed plants in low mountain deserts in the upper and middle reaches of the Manas River in Xinjiang

Through a field survey of low mountain deserts in the upper reaches of the Manas River in Xinjiang, it was found that there were 294 species of seed plants belonging to 174 genera in 44 families, including one gymnosperm species, 43 angiosperm families, and 173 angiosperm genera, in 293 species. Among the families, there are 38 single-species or oligospecies (2～10 species) families (86.37%), and six larger (21～50 species) and medium-sized families (11～20 species). The number of species is 62.93% of the total, which is the main body of the flora; the dominant families are mainly Compositae, Chenopodiaceae, Cruciferae, Gramineae, and Leguminosae. Among the genera, Salsola and Astragalus, represented only by 11～20 species, are the dominant genera in this area. There are 269 species of 172 genera in two to six species and single genera families, accounting for 98.85% and 91.50% of the total genera and species, respectively, which are the main components of the floristic characteristics. Life style is based on herbs (254 species), containing 139 species (including 66 species of short-lived plants) of herbs from 1～2 years old, followed by 110 species of perennial herbs (including 11 species of short-lived plants). Among them, there are five species of parasitic plants, 26 species of shrubs, 12 species of semi-shrubs, and two species of trees. Ecotypes are dominated by mesophytes (198 species), accounting for 67.35%, but xerophytes are mostly the dominant genera and species in this area. The geographical distribution of the flora in this area is complex, exhibiting eight distributional types and 11 subtypes at the genera level, which mainly corresponded to variants in temperate floral distributions (75 genera, accounting for 51.73%), which have a close relationship with the Mediterranean and West Asia to Central Asia distribution area types and their variants (42 genera, accounting for 28.97%).