广西桉树人工林的植物物种组成与区系特征研究

Species Composition and Floristic Characteristics of Eucalyptus spp.Plantations in Guangxi,South China

基于野外调查和文献资料,分析广西桉树人工林维管植物的物种组成及属的区系特征。结果表明,广西桉树人工林中有维管植物120科369属584种,包含蕨类植物15科28属49种、裸子植物4科4属6种和被子植物101科337属529种,分别占广西维管植物科、属、种总数的38.83%、18.35%和6.37%,表明桉树人工林的植物物种多样性较低。桉树人工林中植物以灌木(201种)为主,藤本(91种)最少。在科、属水平上,以大科、中等科、单种属和少种属为主,大多数植物属和种趋于大科及单种属、少种属内,表明植物区系具有一定的分化潜能,科属组成较分散。优势科属种含有丰富的原始类群,表明区系成分具有一定的古老性。属分布区类型共有14个分布型和15个变型,热带与温带性质属的比值(R/T值)达5.37,以热带成分为主,其中泛热带成分占最大优势。区系中出现中国特有分布类型仅2属2种。总的来看,广西桉树人工林植物的区系成分复杂,热带性质明显,起源古老,但特有成分缺乏,分化程度较低。该研究结果可用于指导开展广西桉树人工林植物物种多样性和区系特征分析,可为桉树人工林的科学管理提供理论依据。

Through integrating field surveys and literature data,this study analyzed the species composition and floristic characteristics of vascular plants in Eucalyptus plantation in Guangxi.The results showed that there were 584 species from 369 genera and 120 families of vascular plants in the Eucalyptus plantation of Guangxi.Among them,ferns consisted of 49 species from 28 genera and 15 families,gymnosperms included 6 species from 4 genera and 4 families,and angiosperms comprised 529 species from 337 genera and 101 families.These values account for 38.83%,18.35%,and 6.37%of the total number of vascular plant families,genera,and species in Guangxi,respectively,indicating relatively low plant diversity in Eucalyptus plantation.Shrubs(201 species)dominated the vegetation,while lianas(91 species)were the least represented.At the family and genus level,this flora was dominated by plurimotypic families,mesotypic family,oligotypic genera and monotypic genera.The vascular plant genera and species tended to be concentrated in plurimotypic families,oligotypic genera and monotypic genera,indicating that the flora had a certain differentiation potential and the composition of families and genera was relatively scattered.The abundant primitive taxa of dominant families,genera,and species indicate that the floristic components had a certain degree of antiquity.There were a total of 14 distribution types and 15 subtypes in the genus distribution area.The ratio of tropical to temperate genera(R/T value)was 5.37,with tropical components being the main component,with pan tropical components being the most dominant.Only 2 genera and 2 species were endemic to China in the flora.Overall,the flora of Eucalyptus plantation in Guangxi exhibited complex composition,apparent tropical characteristics,ancient origins,but lacked unique elements,and had relatively low differentiation.These research findings could be utilized to guide the analysis of plant diversity and floristic characteristics in Eucalyptus plantation in Guangxi.