Abstract: This paper studied the size characters of rainfall in south edge of Ga rbantunggut Desert and the responses of different life-form plants there to sma ll rainfall events. Based on the analysis of the precipitation data in 1998〖KG-*2〗-〖KG-*7〗2007, the study area had a high frequency but low amount of precipitation. Rainfall events occurred every 6 days averagely, and most (898%) of the events were ≤5 mm. Sixteen representative plant species were selected and their leaf relative water content (RWC) was used as the parameter to investigate the respon ses of different life-form plants in the area to small rainfall events (1, 2, 3 , 4, and 5 mm). The results showed that all 11 herb species had different degr ees of responses to 2〖KG-*2〗-〖KG-*7〗5 mm rainfall, and only one shrub species Ceratoides late ens responded to 4 mm rainfall significantly. The leaf RWC of the 12 species inc reased significantly after one day of rainfall, suggesting that these species ha d significant responses to small rainfall events (≤5 mm). Sub-shrub (Seriphi dium santolinum), shrub (Haloxylon ammodendron, Tamarix ramosissima), and small tree (Haloxylon persicum) did not respond to the rainfall events ≤5 mm. Small rainfall events mainly benefited herb species, and the hi gh frequency but low amount of rainfall partially explained the relatively high vegetation cover in this area.

Key words: MtXiaowutai, Subalpine meadow, Habitat effective temperature, Species distribution