Diversity and floristic analysis of wetland plants in the middle and lower reaches of the Yarkant River in Xinjiang

To investigate and analyze the current status of plant resources and their floristic composition in the Wetland Nature Reserve in the Middle and Lower Reaches of the Yarkant River, Xinjiang, and thereby promote the coordinated development of regional ecosystems, an investigation was conducted in the Yonganba North Reservoir, Xiaohaizi Reservoir, Yonganba South Reservoir, and Qianjin Reservoir within the Wetland Nature Reserve of the Middle and Lower Reaches of the Yarkant River in Xinjiang. This comprehensive study employed both the line transect method and quadrat method to systematically examine five vegetation type groups across different reservoirs, specifically encompassing the broad-leaved forest vegetation type group, shrub and shrub-grass vegetation type group, desert vegetation type group, meadow vegetation type group, marsh and aquatic vegetation type group. Furthermore, the characteristics of plant community diversity in the main wetlands of the wetland nature reserve were analyzed using the Patrick richness index, Shannon-Wiener diversity index, Simpson dominance index, and Pielou evenness index. The results showed that the wetland reserve contained a total of 39 families, 141 genera, and 217 species of vascular plants. Among these, angiosperms were the most abundant, accounting for 37 families, 139 genera, and 215 species, while pteridophytes and gymnosperms were the least represented, with each category comprising only 1 family, 1 genus, and 1 species. Among all vascular plants in the wetland reserve, Asteraceae and Amaranthaceae accounted for the highest proportion, both representing 16.59% of the total vascular plants, followed by Poaceae at 14.29%. These three families all held significant roles in the region’s vegetation. The distribution types of seed plant genera in the wetland reserve were dominated by temperate genera, while cosmopolitan genera accounted for the next highest proportion. The vegetation types in the wetland reserve were categorized into 6 vegetation types, 9 vegetation subtypes, and 42 formations, with the meadow vegetation type as the dominant type. Among these formations, notably, the Shannon-Wiener diversity index (1.884) and Pielou evenness index (0.734) of the Apocynum pictum formation were significantly higher than those of other formations, while the Patrick richness index of the Tamarix ramosissima formation was the lowest at 5, and the Simpson dominance index of the Astragalus contortuplicatus formation was the lowest at 0.812. These findings provide foundational baseline data for the conservation of wetland vegetation diversity in the Yarkant River Basin and furnish essential scientific information to support the conservation of wetland ecosystems within the Xinjiang region.