天山一号冰川岩面生地衣群落的分类和排序

Quantitative Classification and Ordination of Saxicolous Lichen Communities in Tianshan No.1 Glacier,Xinjiang,China

保护高山地区地衣物种多样性,查明地衣群落物种组成特征是地衣生态学的热点问题。根据野外调查和实验数据,用双向指示种分析(TWINSPAN)和除趋势对应分析(DCA)对天山一号冰川岩面生地衣进行数量分类,并采用典范对应分析(CCA),分析岩面生地衣物种组成与环境变量的关系。结果表明:TWINSPAN分析和DCA排序将一号冰川的46种岩面生地衣分为7个群丛。其中,群丛-3和群丛-5的Simpson’s和Shannon-Wiener多样性指数最大,群丛-3和群丛-5的Simpson’s多样性指数分别为0.93、2.95,Shannon-Wiener多样性指数分别为0.93、2.87;其次群丛-2的Simpson’s和Shannon-Wiener多样性指数分别为0.92和2.68;群丛-7的多样性最低,Simpson’s和Shannon-Wiener多样性指数分别为0.78和1.82。群丛-1和群丛-3的相似性指数最大为0.72;其次,群丛-1和群丛-2、群丛-3和群丛-5的相似性指数均为0.67;群丛-2和群丛-7、群丛-5和群丛-7的相似性最低,相似性指数分别为0.25、0.26。天山一号冰川岩面生地衣的分布与海拔高度、坡度和岩石大小有关;坡向、岩石颜色、风化程度和光照强度对地衣种类分布的影响不显著。

The protection of the alpine lichen species diversity and understanding lichen community species composition characteristics is one of the hot issues of lichen ecological research.By the filed investigation and laboratory experimental data analysis,we classified saxicolous lichens communities in Tianshan No.1 glacier using two way indicators species analysis(TWINSPAN) and detrended correspondence analysis(DCA) methods,the relationship between the overall species composition of saxicolous lichens communities and environmental variables were analyzed with canonical correspondence analysis(CCA).The saxicolous lichen community can be divided into seven association according to the TWINSPAN and DCA analysis.The Simpson’s and Shannon-wiener diversity of Associations 3 and 5 were the highest(0.93,2.95 and 0.93,2.87),followed by Association 2(0.92,2.68),and Association 7(0.78,1.82).The similarity index showed that the maximum similarity of Associations 1 and 3 was 0.72,followed by Associations 1 and 2,and Associations 3 and 5 were 0.67,respectively.The lowest similarity of Association 2 and 7 and Associations 5 and 7 was 0.25 and 0.26,respectively.The CCA ordination results showed that the species composition and distribution pattern of saxicolous lichens were most strongly influenced by altitude,slope and rock size,and did not significantly correlate with aspect,radiation and weathering.