<正>研究了脱水对青冈栎（Cyclobalanopsis glauca）、山杜英（Elaeocarpus sylvestris）、无患子（Sapindus mukorossi）、观光木（Tsoongiodeneron odorum）、香叶树（Lindera communis）和金叶含笑（Michelia foveolata）等6种林木种子浸出液相对电导率、发芽率和发芽指数的影响。结果表明：除无患子外，随脱水时间的延长，其他5个树种种子浸出液相对电导率均有逐渐升高的趋势，发芽指数有比较显著的下降；随着脱水程度的不断加深，6个树种种子的发芽率均有下降的趋势，但树种不同，种子发芽率下降程度和下降过程均有很大差别。6个树种中，无患子种子可归为次正常性种子，其他5个树种种子介于正常性与顽拗性之间，其中青冈栎的耐脱水性最高，山杜英次之，观光木、金叶含笑和香叶树的耐脱水性较差。

Based on the samples data, 6 factors to form an assessment index system were selected and art assessment model of ecological fragile degree with the euclidean distance formula was established. The weights of factor were calculated through respective apparent and recessive Karst types using the method of stratification analysis. Result showed that vegetation and area of bare-rock had more weight and effects among 6 indexes. According to the calculated results of ecological fragile degree, frangibility of 64 samples was assessed and divided into 5 grades, which were slight(≤0.2), light(0.21～0.4), medium(0.41～0.60), strong (0.61～0. 80) and ultra strong(>0. 80). The result also showed that the geologic background was frangible essential to Karst environment and its frangibility degree of environment was decided by vegetation status if other conditions were the same.