Abstract: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 th...