Abstract: The natural conditions and ecological physiology characteristics of Fahtscai (Nostoc flagelliforme Bron et Flah.) growing in 14 counties and one city of Qinghai province were reported in this paper. The research showed that N. flagelliforme grows in dry desert steppes with arid or semiarid continental climate. The soil on which N. flagelliforrne could grow well is the calcic sierolem and light chestunt soil developed from loess mother material during the quaternary period. The soil has strong alkaline reaction, with plenty of calcic deposit. In morphiology and physiology, N. flagelliforme showed strong xerophilous ecological adaptability, including drought-resistance, barren-endurance, addiction to sunshine, calcium and alkal as well as adaptation of temperature variation. The growth of N. flagelliforme exhibited an obvious water rhythm phenomenon.

Key words: Three Gorges Reservoir Area, Pinus massoniana plantation, root, litterfall, soil physical and chemical properties.