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基于木论国家级自然保护区内西南坡一条垂直样带16个样方的调查资料,运用丰富度指数、物种多样性指数和均匀度指数对木论喀斯特森林木本植物多样性的垂直格局进行研究。结果表明:(1)在16个样方中共记录植株5089个,分属48科90属120种。(2)喀斯特森林木本植物群落具有明显的垂直分布格局,采用等级聚类和非度量多维标度排序方法可将植物群落沿海拔梯度划分为3个类型,分别是:下坡位以小果厚壳桂(Cryptocarya austrokweichouensis)和灰岩棒柄花(Cleidion bracteosum)为主要优势种的群落;中坡位以长管越南茜(Rubovietnamia aristata)和罗伞(Brassaiopsis glomerulata)为主要优势种的群落;上坡位以化香树(Platycarya strobilacea)和密花树(Rapanea neriifolia)为主要优势种的群落。沿海拔梯度升高,水热组合发生变化,地带性植被以及群落内的建群种和优势种都发生了变化。(3)物种生活型方面,常绿树种所占的比例高于落叶阔叶树种,针叶树种仅出现在山顶。(4)沿海拔梯度物种丰富度及α多样性指数中的Shannon-Wiener指数曲线均符合单峰格局,峰值出现在坡腰位置。(5)β多样性指数起伏较大,总体上β多样性随着海拔的升高呈递减的趋势。
Based on the data of 16 quadrats in a vertical transect on the southwestern slope in Mulun National Nature Reserve, the vertical pattern of woody plant diversity in Karst forests was studied by using the indices of richness, species diversity and evenness the study. The results showed that: (1) A total of 5089 plants were recorded in 16 quadrats, belonging to 48 families, 90 genera and 120 species. (2) The woody plant community in karst forest has obvious vertical distribution pattern. The hierarchical clustering and non-metric multi-dimensional scale sorting method can be used to divide the plant community into three types along the altitude gradient, which are as follows: Cryptocarya austrokweichouensis and Cleidion bracteosum were the main dominant species. The mid-slope was dominated by Rubovietnamia aristata and Brassaiopsis glomerulata. The upper slope is dominated by Platycarya strobilacea and Rapanea neriifolia. Along the elevation gradient, hydrothermal combination changes, zonal vegetation and community-based species and dominant species have changed. (3) As for species life type, the proportion of evergreen species is higher than that of deciduous broad-leaved species, and conifer species only appear on the top of the mountain. (4) The Shannon-Wiener index curves along the altitudinal gradient and Shannon-Wiener index of the α diversity index all fit the unimodal pattern, with the peak appearing on the position of the slope. (5) β diversity index ups and downs, in general, β diversity showed a decreasing trend with the elevation.