新疆博格达山地面生地衣群落数量分类及物种多样性

根据对新疆博格达山地面生地衣群落27个样点(20 m×20 m)调查的数据,以各地衣种的盖度为指标结合双向指示种分析方法(TWINSPAN)和除趋势对应分析法(DCA)对博格达山地面生地衣群落进行数量分类并分析了群落结构特征及其多样性和相似性。采用典范对应分析法(CCA)对各群落的物种分布格局与环境因子的关系进行了探讨。结果表明,TWINSPAN分析和DCA排序将分布在博格达山的37种地面生地衣分为以下5个群丛。群丛1:膜地卷(Peltigera membranacea)+伴藓大孢蜈蚣衣(Physconia muscigena)群丛;群丛2:地卷(Peltigera rufescens)+伴藓大孢蜈蚣衣(Physconia muscigena)群丛;群丛3:裂边地卷(Peltigera degenii)+平盘软地卷(Peltigera elisabethae)群丛;群丛4:喇叭石蕊(Cladonia pyxidata)+犬地卷(Peltigera canina)群丛;群丛5:盾鳞衣(Placidium squamulosum)+缠结茸枝衣(Seirophora contortuplicata)群丛。物种多样性以群丛4最大为3.427;群丛1最小为0.672;群丛1和群丛4间的相似性最高为0.889,群丛3和群丛4相似性系数最低为0.607。CCA排序结果反映,该地区地面生地衣的分布受到森林植被郁闭度、人为干扰、光照强度的影响,而地表植被盖度和土壤pH等因素的影响不大。

Numerical classification and species diversity of terricolous lichen communities in Bogda Mountain of Xinjiang, China

Based on the 27 quadrat (20 m×20 m) investigation data of terricolus lichen communities in Bogda Mountain, the quantitative classification of species was carried out by two way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DCA). The communities'' structure characteristics, species diversity and similarity index were also analyzed. The relationship between species distribution of terricolous lichens and seven environmental factors was studied by canonical correspondence analysis (CCA). The results show that the terricolous lichen community can be divided into the following five associations according to the TWINSPAN analysis and DCA ordination. They are Association 1 (Assoc. Peltigera membranacea + Physconia muscigena); Association 2 (Assoc. Peltigera rufescens + Physconia muscigena); Association 3 (Assoc. Peltigera degenii + Peltigera elisabethae); Association 4 (Assoc. Cladonia pyxidata + Peltigera canina); and Association 5 (Assoc. Placidium squamulosum+Seirophora contortuplicata). Association 4 had the highest species diversity of 3.427 and Association 1 had the lowest diversity of 0.672; similarity between the Association 1 and 4 was the highest of 0.889 and Association between 3 and 4 was the lowest of 0.607. The CCA ordination result showed that the species composition and distribution pattern of terricolous lichens were most strongly influenced by light intensity, canopy density and human disturbance; the distribution patterns of lichen community were not significantly correlated with vegetation coverage and soil pH.