海南六连岭省级自然保护区建立于1981年,掌握其植物群落的分类排序对植物保护与生态管理具有重要意义。为揭示海南六连岭省级自然保护区的植物组成、植物群落与环境因子之间的关系,根据典型样地的调查数据和有效环境数据,采用双向指示种分析(TWINSPAN分类)和典范对应分析(CCA二维排序)对自然保护区内调查到的植物群落进行数量分类和排序。结果表明:1)自然保护区主要由热带低地次生林组成,在样地内记录到的植物有72科145属211种,其中,乔木层127种,灌木层50种,草本层34种。2)TWINSPAN分类结果表明,自然保护区内的次生林可以划分为5个群落,分别为岭南山竹子-白颜树-大白藤+山骨罗竹群落、岭南山竹子+单叶豆群落、黄杞+岭南山竹子群落、黄桐+白颜树-鹅掌柴+小盘木-海南轴榈+露兜草群落和鹅掌柴+美叶菜豆树群落,乔木植物在群落中占主导地位。3)CCA二维排序结果表明,年均降水量、年平均气温和海拔是影响该区域植物群落分布的主要环境因子;年均降水量、年平均气温和海拔等重要环境因子对植物群落的乔木层优势种存在一定的影响。

The Hainan Liulianling Provincial Nature Reserve(LPNR)was established in 1981,and mastering the classification and ordination of plant communities in the reserve is of great significance for plant protection and ecological management.To reveal the species composition of plants in the LPNR and the ecological relationships between plant communities and environmental factors,we conducted a numerical classification and ordination of the surveyed plant communities using two-way indicator species analysis(TWINSPAN classification)and canonical correspondence analysis(CCA two-dimensional ordination)with typical plot survey data and valid environmental data.This study analyzed the distribution patterns of plant communities in relation to environmental factors.The results indicated that:1)LPNR was mainly composed of tropical lowland secondary forests.A total of 211 plant species from 145 genera and 72 families were recorded in the survey plots,including 127 species in the tree layer,50 species in the shrub layer,and 34 species in the herb layer;2)According to the TWINSPAN classification method,the secondary forests within the reserve were divided into five communities,namely the Garcinia oblongifolia-Gironniera subaequalis-Calamus faberii+Schizostachyum hainanense,Garcinia oblongifolia+Ellipanthus glabrifolius,Engelhardia roxburghiana+Garcinia oblongifolia,Endospermum chinense+Gironniera subaequalis-Heptapleurum heptaphyllum+Microdesmis caseariifolia-Licuala hainanensis+Pandanus austrosinensis,and Heptapleurum heptaphyllum+Radermachera frondosa.All these communities were dominated by woody plants;3)The results of the CCA two-dimensional ordination showed that annual precipitation,annul mean temperature,and altitude were the main environmental factors influencing the distribution of plant communities in this area.Additionally,the biplot of t-values indicated that these significant environmental factors,such as annual precipitation,annul mean temperature,and altitude,had certain impacts on the dominant species in the tree plant communities.