中文摘要：

应用双向指示种分析和除趋势对应分析对阿尔泰山两河源国家级自然保护区的朽木生地衣群落进行了数量分类。初步结果表明，该自然保护区朽木生地衣共有43种，隶属于5日、14科、20属，它们组成了以下4个地衣群落。群落（I）：分布在样点1、2、3、4、5中，包括15种地衣种类，命名为对开蜈蚣衣＋半羽蜈蚣衣＋红心黑蜈蚣衣群落。群落（Ⅱ）：分布在样点6、7、8、9、11中，包括25种地衣，命名为尖头石蕊＋粉石蕊＋矮石蕊群落。群落（Ⅲ）：由样点10、12、13、14、16组成，常见的地衣种类有19个种，命名为蜡黄橙衣＋茎口果粉衣＋冷杉粉衣群落。群落（Ⅳ）：包括样点15、17、18、19和20，由22个地衣种组成。命名为疑小梅衣＋同色黄烛衣＋脱落网衣群落。群落I和群落Ⅱ的相似性最高为0．723，其次为群落I和群落Ⅲ为0．609，群落Ⅲ和群落Ⅳ之间的相似性最低为0．262。群落Ⅲ的多样性最大为1．954；其次为群落Ⅱ和群落I，分别为1．742和我1．685，群落Ⅳ的多样性最低为0．543。各群落的相似性和多样性之间的差异与其所处环境和朽木树种的多样性有关。同时发现在研究地区的朽木生地衣群落的分布与海拔高度、朽木腐蚀程度、朽木大小、森林郁闭度等因子具有密切的关系。

英文摘要：

The community structure and species diversity of the dead wood dwelling lichens in forest ecosystem of Altay Two River Sources National Natural Reserve were studied using two-way indicator species analysis and detrended correspondence analysis methods. The relation between the lichen species distribution pattern and environmental factors were analyzed according to ca- nonical correspondence analysis results. Forty-three dead wood dwelling lichens species belonging to 20 genera and 14 families of 5 orders were found in this ecosystem. According to the quantitative analysis results, the lichen communities were divided into the following four types： community Ⅰ ： Physcia dimidiate＋Ph, semipinnata＋Phaeophyscia erythrocardia; community Ⅱ： Cladonia subulata＋CI, fimbriata＋CI, humilis; community Ⅲ： Caloplaca cerina＋Calicium abietinum＋Chaenotheca stemonia; community IV Parmeliopsis ambigua＋Candelaria concolor＋Lecidea elabens. The similarity index of community I and Ⅱ was and that of community I and Ⅲ （0.609） ranked second; the lowest similarity occurred between community Ⅲ community Ⅲ holds the highest rank in species divers munity Ⅳ ranks lowest （0.543）. It was found that, the ity （1 dead 954）, then community Ⅱ （1.742） and community I wood dwelling lichen species composition and distr the highest （0.723）, and IV（0.262）. The （1.685）, while com- bution were mainly affected by the factors such as altitude, dead wood decayed degree, canopy density and dead wood volume