In order to provide a theoretical basis for the water cycle and rocky desertification control of karst ecosystems, this paper studies the water retention and absorption abilities of five moss species, i.e. Erythrodontium julaceum, Barbula unguiculata, Bryum argenteum, Eurohypnum leptothollum and Racomitrium japonicum, which are commonly seen in the rocky desertification area of Puding, Guizhou Province. The results show that, the reserve mass of five epilithic mosses ranges from 0.71 t·hm-2 to 3.91 t·hm-2, with the largest reserve of 3.91 t·hm-2 for E. julaceum.The highest water retention capacity is 761.9％ for R. japonicum, E. leptothollum is the second of 653.8％, and the smallest is 551.7％ for B. argenteum. E. julaceum and E. leptothollum are the dominant species with the highest water retention capacity.The highest water retention rate was 38.2％ for E. leptothollum, R. japonicum ia the second of 33.6％ and the lowest is 15.2％ for B. argenteum. The water absorption processes of the five mosses include two ways, i.e. external and internal water absorptions. There are differences in the time of water absorption and saturation for the moss species. Five species had the same water absorption dynamic reflected by the S type saturation curve. When the water content is below 25 g, the water absorption rate of the plants is directly proportional to the amount of water added. When the external water content increases to or above 25 g, the water absorption rate of the plants gradually trends to reach the maximum.%选择贵州普定石漠化区域常见的石生穗枝赤齿藓 (Erythrodontium julaceum) 、扭口藓 (Barbula unguiculata) 、真藓 (Bryum argenteum) 、美灰藓 (Eurohypnum leptothollum) 和东亚砂藓 (Racomitrium japonicum) 为对象, 研究它们的持水性能和吸水特征, 为喀斯特生态系统水循环和石漠化治理提供理论依据.结果表明:5种石生苔藓植物的储量在0.71～3.91 t·hm-2之间, 以穗枝赤齿藓的3.91 t·hm-2储量最大;东亚砂藓的最大持水率最高, 为761.9％, 美灰藓的653.8％次之, 真藓的551.7％最小;最大持水能力穗枝赤齿藓和美灰藓占据较大的优势, 保水率美灰藓38.2％最强, 东亚砂藓为33.6％次之, 真藓15.2％最弱.5种石生苔藓的吸水过程包括外和内吸水两种途径, 其吸水饱和的时间物种间存在差异;吸水动力学曲线均表现为S型饱和曲线, 水分在25 g以下时, 植物水分吸收速度与水分加入量成正比, 当外界水分增加到25 g以上后, 植物水分吸收速度逐渐趋于达到最大值.
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