地衣是由低等植物中的藻类与菌类中的真菌和兰细菌共生而成的一群特殊的植物。由于耐寒耐旱对生活中的养分要求不高，在养纷贫瘠、环境恶劣的高山寒漠、平原、戈壁和沙漠中地衣都能生长，因而广泛地分布和生长在不同的生态环境中。有关新疆地衣方面的研究报道集中在物种分类水平上,对于地衣群落结构方面的研究比较少。因此,我们应用多元分析中的主分量分析及聚类分析方法对分布在天山森林生态系统中树生地衣植物群落进行数量分类并对群落结构物种多样性、相似性和均匀度等群落参数进行了比较系统的研究。结果表明, 在西部天山不同森林生态系统中树生地衣群落的分布与海拔高度和树种有密切的关系, 不同海拔的不同类型的森林生态系统中分布着不同种类的树生地衣植物。 根据多元分析结果和生境的综合特征,该地区的树生地衣可划分为4种类型: 1) 茎口果粉衣+金黄茶衣群丛Chaenotheca stemonea+Candellaria aurella Association; 2)叉小孢衣+裸扁枝衣+粉唇蜈蚣衣群丛Bryoria furcellata+Evernia esorediosa+Physcia tribacoides Association; 3)亚广开梅衣+槽梅衣+疑小梅衣群丛Parmelia fertilis+Parmelia sulcata+Parmeliopsis ambigua Association; 4)睫毛黑蜈蚣衣+黑蜈蚣衣群丛Phaeophyscia ciliata+Phaeophyscia nigricans Association。其群落多样性指数以亚广开梅衣+槽梅衣+疑小梅衣群丛为最高 (1.920) , 叉小孢衣+裸扁枝衣+粉唇蜈蚣衣群丛为最低 (1.562)。
Using principal component analysis (PCA) and cluster analysis method, the community structure and species diversity characteristics of corticolous lichen communities in a western Tianshan forest ecosystem were studied in this paper. The results showed that corticolous lichen communities differed with altitude and on different tree types. Based on the results of a multivariate analysis and universal characteristics of habitat, the corticolous lichens communities in the forest ecosystem in western Tianshan can be generalized into four major types: 1) Chaenotheca stemonea + Candellaria aurella Association; 2) Bryoria furcellata + Evernia esorediosa + Physcia tribacoides Association; 3) Parmelia fertilis + Parmelia sulcata + Parmeliopsis ambigua Association; 4) Phaeophyscia ciliata + Phaeophyscia nigricans Association. Community 3 had the highest species diversity (1.920) and community 2 had the lowest (1.562). At the same time, we found that altitude and forest canopy density were the two most important environmental factors influencing the structural patterns of corticolous lichen communities in these forest ecosystems.