遂昌乌溪江流域山蜡梅生境群落特征与物种多样性

Habitat community characteristics and species diversity of Chimonanthus nitens in Wuxi River Basin,Suichang

【目的】山蜡梅Chimonanthus nitens是中国特有的茶药两用野生珍稀植物。随着对山蜡梅药用功能的开发和市场需求的增加,野生资源受到严重破坏。研究山蜡梅种群生境群落的结构特征及物种多样性,探讨山蜡梅的适生环境,可为山蜡梅种群的保护和开发利用提供科学依据。【方法】在实地踏查的基础上,于遂昌乌溪江流域选取山蜡梅典型群落,设置5块400 m^(2)样地,调查分析该群落的植物区系特征、物种组成、群落结构及物种多样性。【结果】(1)山蜡梅生境群落区系组成物种以泛热带分布、东亚和北美洲间断分布、北温带分布为主,热带与温带分布属比例分别为50.70%和40.85%,具有典型中亚热带植物区系特点。(2)2000 m^(2)样地内共有维管植物47科80属105种,科属种类丰富、组成分散,优势科为樟科Lauraceae、蔷薇科Rosaceae、壳斗科Fagaceae、豆科Fabaceae和茜草科Rubiaceae。(3)山蜡梅种群和生境群落径级结构均呈倒“J”型,为增长型结构,乔木层重要值前5位的树种为杉木Cunninghamia lanceolata(11.67%)、山蜡梅(11.63%)、苦槠Castanopsis sclerophylla(9.05%)、檵木Loropetalum chinense(7.28%)和石栎Lithocarpus glaber(7.08%)。群落垂直结构层次丰富。运用K-means聚类,乔木层胸径≥1 cm的个体根据树高可分为5个林层,山蜡梅主要位于乔木Ⅰ层[1.0,4.5)m和乔木Ⅱ层[4.5,7.0)m。(4)不同样地物种多样性指数差异较大,Margalef指数、Shannon-Wiener指数、Simpson指数、Pielou均匀度指数及优势度指数分别为1.98~3.84、1.56~2.37、0.72~0.87、0.69~0.86、1.98~3.85。【结论】遂昌乌溪江流域山蜡梅生境群落物种组成丰富,垂直结构复杂,小、中径级林木占绝大多数,为增长型群落,物种多样性整体较高。建议在保护现有群落生境前提下,在乌溪江流域开展山蜡梅仿野生栽培试验,合理开发利用山蜡梅资源。

[Objective]Chimonanthus nitens is a rare wild plant unique to China both for tea and medicine.The wild resources have been seriously damaged with the development of its medicinal function and the increase of market demand.This study aims to explore the structure characteristics and species diversity of the habitat community of C.nitens population,as well as its suitable living environment,so as to provide a scientific basis for the protection,development and utilization of C.nitens population.[Method]Based on the field survey,the typical community of C.nitens was selected in Wuxi River Basin of Suichang,and five 400 m^(2) plots were set up to investigate and analyze the flora,species composition,community structure and species diversity of the community.[Result](1)The flora of C.nitens community was dominated by pantropical distributions,disjuncted distribution in East Asia and North America,and northern temperate distribution.The proportions of tropical and temperate genera were 50.70%and 40.85%,respectively,with typical characteristics of mid-subtropical flora.(2)There were 105 species in the 2000 m^(2) sample plots,belonging to 80 genera and 47 families.The families and genera were rich in species and dispersed in composition.The dominant families were Lauraceae,Rosaceae,Fagaceae,Fabaceae and Rubiaceae.(3)The diameter class structure of C.nitens population and habitat community was an inverted“J”type,indicating a growth type.The top 5 tree species with important values of the arbor layer were Cunninghamia lanceolata(11.67%),Chimonanthus nitens(11.63%),Castanopsis sclerophylla(9.05%),Loropetalum chinense(7.28%)and Lithocarpus glaber(7.08%).The vertical structure of the community was rich.K-means clustering showed that individuals with DBH≥1 cm in the tree layer could be divided into five forest layers according to the tree height.The main location of the community was in the tree layerⅠ[1.0,4.5)m and tree layerⅡ[4.5,7.0)m.(4)The species diversity index varied greatly in different regions.Margalef index,Shannon-Wiener index,Simpson index,Pielou index and Dominance index were 1.98−3.84,1.56−2.37,0.72−0.87,0.69−0.86 and 1.98−3.85,respectively.[Conclusion]The community of wild Chimonanthus nitens in Wuxi River Basin of Suichang has rich species composition and complex vertical structure.Small and medium diameter trees account for the vast majority,which is an increasing community with high species diversity as a whole.Under the premise of protecting the existing community habitat,it is suggested to carry out experiments imitating wild cultivation to rationally develop and utilize the wild resources of Chimonanthus nitens.