Abstract: The east southeast of Tibetan Plateau is the distribution center of Rheum palmatum.The species is found in scrubsand grassland from 2500 to 4400 meters above sea level and suitable to develop its populations in fertile and good -textured soils.For Rheum palmatum,P content in soil is largely lower than that in both leaves and rhizomes,and Fe content is soil>rhizomes>leaves.Amang them ,there is no significant difference between rhizomes and leaves but Fe content in soil is 50-110times higher than that of rhizomes and leaves.Contents of Na,Mn and Cu are soil>leaves>rhizomes,and Ca content is soil

Key words: Rheum palmatum, Distribution center, Element content, Net photosynthesis rate

摘要： 掌叶大黄(Rheum palmatum L．)主要以青藏高原东部和东南部为其分布中心，多见于海拔2500－4400m的林缘、灌丛和草地。适生于土壤肥沃、质地疏松的阴坡或半阴坡。掌叶大黄土壤P的含量远低于大黄根茎和叶，Fe含量则为土壤＞根茎＞叶，其中，根茎与叶相差不大，但它们与土壤相差50－110倍；Na、Mn、Gu的含量表现为土壤＞叶＞根茎，Ca的含量为土壤＜叶＜根茎。掌叶大黄净光合速率日变化在晴天呈现出典型的单峰曲线，这主要缘于在植物生长季节，高原上的光照和温度的合理搭配有利于光合作用。

关键词: 掌叶大黄, 分布, 元素含量, 净光合速率