[目的] 研究老秃顶子冰缘地貌植物群落的多样性特征,为其上植被的保护提供科学依据. [方法] 基于48个样地的群落调查数据,采用物种丰富度指数和α多样性指数,对石海、石河、石流坡3种冰缘地貌植物群落的多样性进行定量研究,并对其影响因素进行分析. [结果] (1) 植被划分为22个群系,6种植被类型,其中石河地貌上植被类型以落叶阔叶林、针阔混交林为主;石海地貌上以灌丛、灌草丛为主;石流坡地貌上以针阔混交林为主,22个群系对应分布于3种地貌,有些群系具有专有性,有些具有共有性.(2) 3种冰缘地貌群落总体综合多样性指数大小依次为:石河 >石流坡 >石海,乔木层、灌木层综合多样性指数变化均次为:石河 >石流坡 >石海;草本层依次为石海 >石流坡 >石河.(3) 不同植被类型、不同植物群系的物种多样性因所处的生境特征不同而出现差异.(4) 地形因子中的海拔对植物群落物种多样性指数影响最大,且灌木层的物种多样性对海拔敏感程度最小. [结论] 研究区植物群落的多样性特征较好,海拔是影响多样性指数的主导因子.
[Objective] The objective of the paper is to investigate the plant community diversity in Periglacial Landform of Mount Laotudingzi in order to provide the scientific basis for plant protection in this area. [Methods] Based on the data collected from 48 sample plots, we used species richness index and α diversity index to analyze the species diversity of the plant communities in rock stream, rock block field and rock glacier slope of Mount Laotudingzi. We also analyzed the related envitonmental factors. [Results] (1) Plant communities can be divided into 16 forest formations and 6 bushy formations belonging to 6 vegetation types which were broadleaved deciduous forest, theropencedrymion, dark coniferous forest, elfin forest, bush wood and meadow thicket. Of them, the theropencedrymion, broadleaved deciduous forest and dark coniferous forest mainly distributed in landform of rock stream; The bush wood and meadow thicket, the theropencedrymion and elfin forest mainly distributed in landform of rock block fields. The theropencedrymion, broadleaved deciduous forest, bush wood, elfin forest mainly distributed in landform of rock glacier side. Among 22 formations, some were distributed very locally, some may occur in all three habitats.(2) The value of comprehensive biodiversity index of plant community was: rock stream> rock glacier slop > rock block field; The value of biodiversity index of tree layer and shrub layer was also: rock stream> rock glacier slop > rock block field; The value of biodiversity index of herb layer was: rock block field> rock glacier slop > rock stream; (3) Species diversity was significantly different between different vegetation types;(4) Among the topographic factors, the altitude had the greatest impact on species diversity index, and the diversity index of shrub layer was the least sensitive to the elevation change. [Conclusion] The study area has relative high diversity, altitude is the dominant factor affecting the diversity pattern.