青藏高原特有种子植物区系特征及多样性分布格局

青藏高原拥有丰富的种子植物, 但对该地区特有植物的区系特征以及多样性还鲜有报道。本文通过植物志(书)以及在线数据库, 整理了只分布于青藏高原地区的种子植物名录及其地理分布, 分析了它们的科属特征、区系成分以及多样性空间分布格局。结果表明: 青藏高原共有特有种子植物3,764种, 隶属113科519属, 多数为草本植物(76.3%); 包含100种以上的科有菊科、毛茛科、列当科等15个, 属有马先蒿属(Pedicularis)、杜鹃花属(Rhododendron)、紫堇属(Corydalis)等7个; 从属的区系成分来看, 温带成分占主导(67.5%)。青藏高原特有植物多样性格局呈现从高原东南部向西北部逐渐递减的趋势, 其中东喜马拉雅-横断山脉的物种多样性非常丰富, 而且多数物种分布在高原的中海拔地带。理解青藏高原特有物种的特征及多样性格局对探讨高原植物区系的演化历史和物种保护有重要启示。

Floristic characteristics and diversity patterns of seed plants endemic to the Tibetan Plateau

The Tibetan Plateau (TP) harbors numerous seed plants, however, the floristic characteristics and diversity patterns of plants endemic to this region have been rarely studied. Based on several monographs and online databases, we compiled a list of seed plants that exclusively occur on the TP as well as their distribution at the county level. We further explored their characteristics, floristic composition and spatial distribution patterns. We identified 3,764 endemic seed plants belonging to 519 genera and 113 families, 76.3% of which are herbaceous plants. Among them, 15 families (e.g. Asteraceae, Ranunculaceae, Orobanchaceae) and 7 genera (e.g. Pedicularis, Rhododendron, Corydalis) contain over 100 endemic species. Floristic composition analysis indicates that 67.5% of these endemic plants are temperate species. Species diversity declined gradually from the southeast to the northwest with hotspots located within the East Himalaya-Hengduan Mountains. Vertically, most species occurred at intermediate elevations. Understanding floristic characteristics and diversity patterns of Tibetan endemic flora shed light on future studies on the evolutional history and conservation practices in this area.