中文摘要：

紫萼藓科（Grimmiaceae）是典型的多年生旱生藓类，我国有紫萼藓属（Grimmia）22种、砂藓属（Racomitrium）23种。本文利用我国紫萼藓属172个、砂藓属180个地理分布记录，以及对应分析区的年均降雨量和年均温度数据，建立了这两个气候因子影响砂藓属和紫萼藓属种数分布的数学模型。发现砂藓属种数分布（Y）与年均降雨量（X1）符合Y=0．07038＋0．0000976X1-0．000000017X12（R=0．1916，P〈0．05），与年均温度（X2）符合Y=0．119948＋0．0114X2—0．0006X22＋0．000006X23（R=0．1604，P〈0．1）；紫萼藓种数分布（Y）与年均降雨量（X1）符合Y=2．6701X1-0．4396（R=0．3016，n=171，P〈0．01），与年均温度（X2）符合Y=0．2164-0．0074X2（R=0．3338，n=171，P〈0．001）。在此基础上，应用地理信息系统（ArcGIS 9．3），直观地展示了砂藓属与紫萼藓属植物在我国潜在的地理分布范围，发现砂藓属在我国浙江、台湾、贵州、湖北、云南、重庆、江苏等地具有较高的分布概率，表现出热带性的分布特点；紫萼藓属在我国渐江、台湾、云南、江苏、辽宁等地分布较高，表现出温带性的分布特点。

英文摘要：

Grimmiaceae was a moss family living in drought environments, with 22 species of Grimmia, and 23 species of Racomitrium in China. Currently, the distribution mathematical models of Racomitrium and Grimmia were established by using geographic distribution records of the two genera, as well as the corre- sponding annual average rainfall and temperature data. The relationship of Racomitrium species distribution （Y） with annual average rainfall （ X1 ） followed Y = 0. 070 38 ＋ 0. 000 097 6 X1 - 0. 000 000 017 X12 （ R = 0. 191 6, P 〈0.05 ）, and with the average annual temperature （X2 ） followed Y = 0. 119 948 ＋ 0. 011 4 X2 - 0. 000 6 X22 ＋ 0. 000 006 X32 （R = 0. 160 4, P 〈 0.1 ） ; and the relationships of Grimmia distribution （Y） with the annual rainfall （X1 ） followed Y = 2. 670 1X1 - 0. 439 6 （R = 0. 301 6, n = 171, P 〈 0.01 ）, with annual average temperature （X2） followed Y=0. 216 4 -0. 007 4X2（R =0. 333 8, n = 171, P 〈0. 001 ）. Based on the above relationships, geographic information system （ ArcGIS 9.3 ） was used to show the poten- tial geographic distribution of Grimmia and Racomitrium in China intuitively. The areas with higher distribu- tion probability of Racomitrium were Zhejiang, Taiwan, Guizhou, Hubei, Yunnan, Chongqing, Jiangsu, with a tropical distribution pattern, while Grimmia showed high distribution probability in Zhejiang, Taiwan, Yunnan, Jiangsu, Liaoning, Anhui, with a temperate distribution pattern.