【摘要】 为揭示拉萨河下游流域外来入侵植物的种类及分布特征，并为保护该区域生物多样性和防治外来入侵植物。通过实地调查、文献查阅和标本数据分析，在拉萨河下游流域共发现59种外来入侵植物，隶属于18科48属，其中菊科（21种）、豆科（8种）和禾本科（6种）为优势科；苋属（Amaranthus L.）、飞蓬属（Erigeron L.）和苦苣菜属（Sonchus L.）为优势属。植物区系分析显示，外来入侵植物中世界广布的科数量占据绝对优势，在属上则以温带分布类型为主，北温带分布类型最为丰富。危害等级从1级至5级分别有7种、15种、3种、24种和10种，其中出现频度最高的种类依次为牛膝菊（Galinsoga parviflora Cav.）、苦苣菜（Sonchus oleraceus L.）、欧洲千里光（Senecio vulgaris L.）。外来入侵植物引入途径主要为无意引入，主要来源于美洲。分段线性回归分析结果表明，随着海拔升高外来入侵植物种类数量显著减少。更多还原

【Abstract】 This study aims to identify alien invasive plants species and their distribution characteristics in the lower reaches of Lhasa River to provide theoretical support for biodiversity conservation and prevention of invasive plants in the region. Through field surveys combining with literature review and specimen data analysis, a total of 59 alien invasive plant species were identified belonging to 18 families and 48 genera, in the study area.Asteraceae(21 species), Fabaceae(8 species), and Poaceae(6 species) were the dominant families and Amaranthus L., Erigeron L., and Sonchus L. were the dominant genera. The result of floristical analysis revealed that the families of alien invasive plants were dominated by wide world distributed type of family and the majority of genera show temperate distribution type, particularly northern temperate distribution type. The risk levels of these invasive species were categorized from 1 to level 5, with 7, 15, 3, 24 and 10 species, respectively. Species of Galinsoga parviflora Cav., Sonchus oleraceus L. and Senecio vulgaris L. have the highest occurrence frequency. The main introducing pathway of invasive plants was unintentionally and originated from the Americas primarily. The result of piecewise linear regression analysis showed that the number of alien invasive plant species decreased significantly with increasing altitude. The ecological environment in the lower reaches of Lhasa River face a potential threat from alien invasive plants with the ongoing process of globalization and the rise in human activities.It is recommended that relevant authorities, research institutions, and universities should prioritize this issue to enhance regulation, public awareness and effective control measures.更多还原