中文摘要：

为了了解蓑藓属（Macromitrium）和木灵藓属（Orthotrichum）这两个木灵藓科中的大属在中国的分布式样及影响其分布的因子,作者基于19个生物气候因子和植被覆盖率数据,以及中国境内蓑藓属131个、木灵藓属66个地理单位的分布数据,应用最大熵算法模型（MaxEnt3.3.2）和地理信息系统（ArcGIS9.3）软件,在属的水平上预测了它们在中国的潜在分布区域。根据综合生境适宜指数,蓑藓属在浙江、台湾、海南等14个省区有较高的生境适宜性,在西北、华北和东北各省区的分布概率很低;木灵藓属在云南、北京、辽宁等13个省区有较高的分布概率,而在华南地区的分布概率较低。随着最湿月份、最冷季度和最湿季节的雨量以及年降雨量的增加,蓑藓属分布概率呈上升趋势;对于木灵藓属而言,其分布概率在年降雨量低于200mm时随着降雨量的增加迅速增高,但是当年降雨量超过200mm时,其分布概率则随着降雨量上升而降低,在最热季节平均温度为15-20℃时达到最高。蓑藓属植物种数（Y）与年均降雨量（X1）的关系符合Y=-0.0369＋0.0003X1（r=0.5347,P〈0.001,n=131）,与年均温度（X2）的关系符合Y=0.0831e0.001X2（r=0.5525,P〈0.001,n=131）;木灵藓属植物种数（Y）与年降雨量（X1）的关系符合Y=1.0008-0.1184lnX1（r=0.4199,P〈0.001,n=66）,与年均温度（X2）符合Y=1/（0.1309X2＋3.4581）（r=0.2524,P〈0.01,n=66）。基于以上函数模拟得到两属植物在中国的种数分布,其中蓑藓属在华南、东南和中南地区,以及云南东南部、西藏东南部有较多的种数分布,木灵藓属在西北、青藏高原、内蒙古、黑龙江等地区有较多的种数分布。

英文摘要：

A maximum entropy algorithm modelling program （MaxEnt 3.3.2） and a GIS software system （ArcGIS9.3） were used to study and model the distribution of 131 occurrences of Macromitrium and 66 occurrences of Orthotrichum in China in relation to 19 bioclimatic variables and percent tree cover. The information obtained can help predict the potential distribution range of these species in China, and also provide an understanding of factors influencing their current geographical distribution patterns so as to achieve better conservation of species diversity in the future. The species occurrence data were obtained from field work, relevant literature and herbarium specimens examined. Based on the integrated habitat suitability indices calculated, results show that Macromitrium have higher habitat suitability in the southeast and some southern provinces of China, i.e., in Zhejiang, Taiwan, Hainan, Fujian, Chongqing, and lower distribution probability in northwest, northeast and some northern provinces. Likewise, Orthotrichum has higher habitat suitability in Yunnan, Beijing, Liaoning, Jilin, Guizhou, Shanxi, Sichuan and Hebei, and lower distributional probability in the southwest. The distribution probability of Macromitrium increases with increased annual precipitation, precipitation in the wettest month, and in both the coldest and wettest quarter of the year. The distribution probability of Orthotrichum increases rapidly with increasing annual precipitation upto 200 mm, and then decreases when annual precipitation exceeds 200 mm. The distribution probability of Orthotrichum reaches its highest peak when the mean temperature of the warmest quarter is between 15 and 20~C. The relationship between species number （Y） of Macromitrium and annual rainfall 0（1）is described by the equation Y = -0.0369＋0.0003）（1 （r = 0.5347, P〈0.001, n = 131）, and with the annual temperature 0（2） by Y = 0.0831e~~~1x2 （r = 0.5525, P〈0.001, n = 131）. The relationship between species number （Y） of Orthotrichum