Studies on certain ecological characteristics of Rheum likiangense in Yushu,Qinghai
青藏高原丽江大黄某些生态学特性的研究

Rheum likiangense was distributed in a limestone region from alt.3500 to 4400 meters and the contiguous area of Sichuan,Qinghai and Tibet.It belongs to a high cold scrub meadow zone and montane cold temperate coniferous forest zone.The spatial distribution pattern of Rheum likiangense population showed contagious when the sampling scale was greater than 1.5m 2 and random when less than 1.5m 2.Daily variation of net photosynthesis rate of the plant showed typical mono peak curve,differing from that of plants in plains at low altitudes,because the compensation of light and temperature in the plateau was helpful to the net photosynthesis of plants in growing season.For Rheum likiangense ,P content in soil was lower than that in both leaves and rhizomes,and Fe content fitted soil>rhizomes>leaves,without significant difference between rhizomes and leaves.Ca,Na,Mn and Cu contents appeared soil>leaves>rhizomes.