高原农业2026，Vol.10Issue(4)：421-437,17.DOI:10.19707/j.cnki.jpa.2026.04.001
西藏杜鹃花属植物空间分布格局解析
Unraveling the Spatial Distribution Patterns of Rhododendron Species in Xizang
摘要
Abstract
This study aimed to elucidate the patterns of spatial aggregation,elevational distribution,and taxonomic compositional differentiation of Rhododendron in Xizang.Field-collected specimen information and records obtained from the Chinese Virtual Herbarium were used to analyze taxon richness,horizontal range size,elevational spectra,and β-diversity components across mountain segments.The taxonomic nomenclature and geographical information of 2,175 valid specimen records were standardized,and the records were assigned to seven mountain segments.Taxon incidence matrices were then constructed at the mountain-segment and elevational-band scales.Analyses included taxon-richness statistics,county-level horizontal range size,elevational midpoint and range breadth,spatial distribution patterns,Jaccard dissimilarity,Sørensen β-diversity partitioning,principal coordinates analysis(PCoA),and unweighted pair-group method with arithmetic mean(UPGMA)clustering.A total of 222 Rhododendron taxa were documented in Xizang,comprising 183 species,25 varieties,and 14 subspecies.The Eastern Himalayas-Yarlung Zangbo Grand Canyon segment,Hengduan Mountains segment within Qamdo and Zayu,and west-central Nyainqêntanglha Mountains segment had the highest taxon richness,with 140,125,and 80 taxa,respectively.The Hengduan Mountains and Eastern Himalayas-Yarlung Zangbo Grand Canyon segments harbored the greatest concentrations of infraspecific taxa and taxa restricted to a single mountain segment.In terms of horizontal distribution,taxa in the narrow-range and restricted-range categories collectively accounted for 68.47%of all the taxa.Elevational richness peaked at 3,700-3,900 m,while the elevational midpoints of most taxa were concentrated between 3,000 and 4,500 m.β-diversity among mountain segments and between adjacent elevational bands was generally dominated by the turnover component.However,the eastern mountainous region of the Northern Xizang Plateau and high-elevation bands had extremely low taxon richness;when compared with those of taxon-rich units,their compositional differences were dominated by the nestedness-resultant component associated with richness differences,indicating compositional impoverishment.The conclusion shows Rhododendron in Xizang exhibits a multiscale differentiation pattern,with the Eastern Himalayas-Yarlung Zangbo Grand Canyon and Hengduan Mountains segments serving as its principal geographical centers and the middle-to high-elevation belts forming its elevational center.The displacement between the richness peak of species and those of varieties and subspecies suggests that middle-to high-elevation belts may represent an important zone of taxonomic differentiation within the genus.The two core mountain segments share a common mid-elevation species pool,whereas their segment-specific elements diverge toward the warm,humid low-elevation end and the cold,humid high-elevation end.This pattern is an important reason why compositional differences among mountain segments and elevational bands are dominated by species replacement(turnover).By contrast,peripheral areas such as the eastern mountainous region of the Northern Xizang Plateau and high-elevation bands are subject to strong environmental filtering,resulting in sharply reduced taxon richness.Their compositional differences from taxon-rich units are therefore expressed primarily as nested impoverishment driven by richness differences.Overall,taxon replacement and environmental filtering in marginal habitats jointly shape the contemporary distribution patterns of Rhododendron in Xizang,with turnover constituting the principal process maintaining spatial and elevational compositional differentiation.关键词
杜鹃花属/喜马拉雅山脉/横断山脉/海拔梯度/水平分布幅度/β多样性Key words
Rhododendron/Himalayas/Hengduan Mountains/elevational gradient/horizontal range size/β-diversity分类
农业科技引用本文复制引用
罗大庆,刘昌胜,薛矗,马智远,李子卓,宋玉..西藏杜鹃花属植物空间分布格局解析[J].高原农业,2026,10(4):421-437,17.基金项目
西藏杜鹃花属野生植物资源评价与利用(XZ202502JD0009). （XZ202502JD0009）
