To clarify the community structure， distribution pattern of wild vascular plants in wetlands of the National Nature Reserve for Black-necked Cranes in the Lhasa River Basin and their relationship with environmental factors， the study conducted field surveys on 23 typical plots in the reserve from 2022 to 2023， using methods such as TWINSPAN classification， CCA ordination， and diversity index analysis， to systematically investigate community type classification， spatial distribution characteristics， environmental driving mechanisms， and the coupling relationship with black-necked crane habitats. Results showed that a total of 114 species of wild vascular plants belonging to 83 genera and 34 families were recorded in the study area， with dicotyledonous herbs as the main components； TWINSPAN classified the communities into 7 types， among which the communities were mainly composed of herbaceous plants， with fewer arbor plants. CCA ordination indicated that longitude， mean annual precipitation ， slope gradient ， and slope aspect were the key environmental factors driving community distribution. Diversity analysis showed that the Shannon-Wiener index （1.31-2.95） and Simpson index （0.37-0.99） were significantly different among communities （P<0.05）， and the Mantel-test confirmed that mean annual precipitation had the most significant impact on the Pielou evenness index and Shannon-Wiener index . Further quantification by RDA analysis showed that longitude， mean annual precipitation， slope aspect， and slope gradient were the core factors regulating community diversity. Among them， the Shannon-Wiener index and Pielou index were positively correlated with mean annual precipitation， and the Simpson index responded significantly to the longitude gradient. The results revealed the adaptation patterns of plateau wetland plant communities to hydrothermal gradients， providing a theoretical basis for the protection of black-necked crane habitats and wetland ecosystem management.

Black-necked crane national nature reserve  /  Quantitative classification  /  Ordination  /  Community diversity  /  Environmental factors