For selecting the populations which had stronger drought resistances, the pot cultivation experiment was conducted to study the effects of long term drought on the daily mean evapotranspiration rate, wilting coefficients, soil moisture utilization rate and SWDI of four plant populations (.Sedum roborowskii, Sedum polytrichoides, Viola prionantha and Poa pratensis ) from June to November in 2010. The results indicated that: (1) The daily mean evapotranspiration rate of two Sedum populations were significantly lower than V. Prionantha and P. Pratensis, and their survival days were far longer than V. Prionantha and P. Pratensis. (2) There were no significant differences in wilting coefficients among two Sedum populations and P. Pratensis, respectively, lower than that of V. Prionantha, significantly; the mean soil moisture utilization rate of Sedum populations was 72. 35% , higher than V. Prionantha, significantly. (3) The SWDI of two Sedum populations were significantly lower than V. Prionantha and P. Pratensis, respectively, so the drought resistances of four species were as follows : S. Roborotvskii^>S. Polytrichoides~>V. Prionantha>P. Pratensis.%于2010年6～11月期间利用盆栽试验研究了持续干旱胁迫对德国景天、中华景天、早开堇菜、草地早熟禾四种地被植物种群的日均蒸腾量及其动态、萎蔫系数、土壤水分利用率、耗水指数的影响.结果表明:两种景天种群的日均蒸腾量都显著低于草地早熟禾和早开堇菜,存活时间都远远大于后两种植物.德国景天、中华景天、草地早熟禾种群的萎蔫系数无显著差异,三者均显著低于早开堇菜.景天种群的平均土壤水分利用率为72.35％,显著高于早开堇菜.德国景天、中华景天的耗水指数显著低于其他两种植物,不同植物的抗旱性为德国景天＞中华景天＞早开堇菜＞草地早熟禾.
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