Bryophytes are widely distributed and constitute an important part in vegetation diversity.More than 20,000 species of bryophytes are found worldwide.Bryophytes play important roles in the ecosystem,particularly in water balance and nutrient accumulation.However,bryophytes are smaller than vascular plants and are often ignored in ecological studies.Spatial patterns of species diversity along the elevation gradient are of great significance in illuminating community ecology.What is the distribution pattern of bryophyte species diversity along an elevation gradient? We do not find the related research in China.The Xiaoqinling National Nature Reserve is located in Lingbao (34°23′-34°31′N,110°23′-110°44′ E,Henan Province,China).This nature reserve covers 31 km from east to west and 12 km from north to south,and spreads over a total area of 15,160 km2.The reserve harbors the highest peak in Henan,with an elevation of 2413.8 m.The area has rich biological resources with a diverse and complex vegetation composition.We constructed 53 plots in a 400m2 area (20 m × 20 m) along the altitudinal gradient in Xiaoqinling,collected all bryophyte species encountered in these 53 plots,and recorded habitat types such as ground,tree trunks,roots,and rotten wood.Investigators carefully checked every comer of each plot to collect all bryophyte species growing on the plot.A total of 1378 specimens were collected.All specimens were transported back to the laboratory and identified.The bryophyte community was classified using multiple regression trees.Ordination analysis was conducted by canonical correspondence analysis,and the generalized linear model was used to study the distribution pattern of species diversity along elevation gradients.Results were as follows.(1) The collected 1378 bryophyte specimens belonged to 33 families,89 genera,and 240 species,including 226 species of mosses and 14 species of liverworts.(2) The bryophyte community was divided into four categories by cross validation:Ⅰ:Brachythecium populeum + Plagiomnium succulentum + Plagiomnium vesicatum;Ⅱ:Brachythecium albicans + Brachythecium curtum + Thuidium kanedae + Mnium laevinerve;Ⅲ:Thuidium kanedae + Jungermannia leiantha + Leskea polycarpa + Trachyphyllum inflexum;Ⅳ:Brachythecium curtum + Plagiothecium nemorale + Plagiomnium integrum.(3) The interpretation of the elevation,slope,and aspect to the distribution of the bryophyte species was 7.29％.(4) The bryophyte species diversity increased with the increase in altitude.In this study,we examined the species composition,classification,and distribution range along elevation gradients of the bryophyte species in Xiaoqinling.The diversity of the bryophyte species along the altitude showed an increasing tendency and differed from the distribution patterns of trees,shrubs,and herbs.Thus,this study provides a reference for research on bryophyte species coexistence and protection of species diversity.Vascular plants and bryophytes coexist in an ecosystem and the relationship between vascular plants and the bryophyte community is complex.However,we did not consider the effect of vascular plants on the bryophyte community and these factors need further analysis.Environmental factors,such as climatic conditions,physical and chemical properties of bark,and light intensity,must also be considered in future studies.%苔藓物种多样性沿海拔梯度呈什么样的分布格局？基于53个20 m×20 m样地,采集并鉴定了样地内所有生境中的苔藓物种;采用多元回归树(multivariate regression trees,MRT)对苔藓植物进行分类;采用典范对应分析(canonical correspondence analysis,CCA)进行排序分析;用广义线性模型(Generalized Linear Model,GLM)研究苔藓物种多样性沿海拔的分布格局.结果如下:(1)采集的1378份苔藓植物标本经过鉴定,共有33科89属240种,其中藓类226种,苔类14种;(2)经交叉验证认为本区苔藓植物可分为4类,Ⅰ长肋青藓(Brachythecium populeum)+大叶匐灯藓(Plagiomnium succulentum)+圆叶匐灯藓(Plagiomnium vesicatum)群落,Ⅱ灰白青藓(Brachythecium albicans)+宽叶青藓(Brachythecium curtum)+短肋羽藓(Thuidium kanedae)+平肋提灯藓(Mnium laevinerve)群落,Ⅲ短肋羽藓(Thuidium kanedae)+光萼叶苔(Jungermannia leiantha)+薄罗藓(Leskea polycarpa)+叉肋藓(Trachyphyllum inflexum)群落,Ⅳ宽叶青藓(Brachythecium curtum)+垂蒴棉藓(Plagiothecium nemorale)+全缘匐灯藓(Plagiomnium integrum)群落;(3)海拔、坡度和坡向对苔藓物种分布的解释量为7.29％;(4)苔藓物种多样性随海拔的变化成明显的上升格局.通过研究了解了小秦岭国家级自然保护区苔藓物种组成、群丛划分以及每种苔藓植物的海拔分布范围;苔藓物种多样性随海拔的上升呈显著的上升格局,与乔木、灌木和草本的分布格局不同.希望此研究能为苔藓植物生态学研究和物种多样性保护提供参考.
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