哀牢山植物多样性垂直分布格局

以设于哀牢山各植物群的样地调查材料为依据,分析了哀牢山东、西坡不同海拔高度地带性植物群落乔木层林木的高、径垂直分布特征,植物群落生物多样性指数的垂直分布态势。结果表明:该山地植物群落乔木层和灌木层的植物物种多样性沿海拔梯度呈单峰型分布格局,以中山湿性常绿阔叶林乔木层林木的最大和平均树高、最大胸径值和物种多样性指数最大;而灌木层植物物种多样性指数最大值出现在中山湿性常绿阔叶林带下的季风常绿阔叶林和半湿性常绿阔叶林带内;而草本层植物的物种多样性指数则沿海拔梯度上升呈整体减小的趋势;累加其植物群落乔、灌、草3层植物的物种多样性指数,哀牢山东、西坡植物群落的Shannon-Weiner指数和物种丰富度最大值出现在海拔高度2000 m左右。在相同海拔高度处,西坡植物群落的植物物种多样性高于东坡,季风常绿阔叶林的物种多样性大于半湿性常绿阔叶林,而山顶苔藓矮林的植物物种多样性最小。

Vertical Distribution Patterns of Plant Species Diversity in Ailao Mountains

Based on the data from sampling plots,the vertical distribution patterns of plant community and species diversity index in eastern and western Mt.Ailao were studied.The results showed that the distribution of species diversity of both tree layer and shrub layer was single peak pattern along altitude gradients.The biggest and average tree height,the biggest DBH of trees and species diversity in mid-montane moist evergreen broadleaved forest was the biggest.The highest value of species diversity of shrub layer occurred in the transit area of mid-montane moist evergreen broadleaved forest,monsoon evergreen forest and semi-moist evergreen broadleaved forest,and the species diversity of grass layer showed the decreasing tendency with the increase of altitude.The Shannon-Weiner index and maximum value of species richness of both eastern and western Mt.Ailao occurred in the altitude around 2000 m.The species diversity of western slope was higher than that of eastern slope,the species diversity of monsoon evergreen broadleaved forest was higher than semi-moist evergreen broadleaved forest,the minimum species diversity was observed in mountain mossy dwarf forest.