The vertical distribution pattern of alpine vegetation in the Rongbu River Basin of Mount Qomolangma

<p indent="0mm">Vegetation on the Qinghai-Xizang Plateau exhibits a distinctive “three-dimensional” distribution along latitudinal, longitudinal, and vertical gradients. However, due to ecological limitations and accessibility challenges, previous vegetation surveys were primarily conducted along roads, railways, or foothill areas. These surveys often inferred montane vertical zonation based on relationships between vegetation and climatic factors in baseline regions, introducing significant uncertainty. In this study, we selected four baseline elevations and surveyed eight mountains (including both shady and sunny slopes) in the Rongbu River Basin of Mount Qomolangma to assess plant composition across the entire vertical band. We examined the effects of different baseline elevation survey scenarios on plant composition and vegetation types. Our findings revealed significant differences in community species composition under 4 baseline conditions, with shifts in species dominance. Specifically, plant composition and vegetation types at high-altitude foothills differed markedly from those at similar altitudes near mountain summits. Moreover, incomplete slope surveys severely distorted the vertical distribution of montane vegetation. In particular, surveys conducted at 1/4, 2/4, and 3/4 of the baseline underestimated the vertical distribution height of the alpine shrub zone by 527, 336, and 268 m, respectively, while overestimated the alpine meadow zone by 440, 329, and 271 m, respectively. These results indicate that vegetation types derived from foothill elevations do not accurately reflect the vertical species composition and vegetation distribution of the mountains.