乌金山植物群落物种多样性的垂直分布格局

Vertical Distribution Pattern of Plant Community Species Diversity in Mt.Wujin

在乌金山适合地段沿海拔梯度设置11个样地,采用数量分类,对乌金山植物群落类型、物种组成和物种多样性的垂直分布格局进行调查.结果表明:(1)随着海拔的升高,森林群落依次为油松林、侧柏林、油松侧柏混交林、油松山桃山杏混交林、白皮松林、油松白皮松混交林.(2)11个样地中共调查到乔木13种,灌木16种,草本31种.(3)物种丰富度成明显的单峰分布格局,最大的丰富度出现在中海拔群落中.木本植物的物种丰富度随着海拔高度的增加而下降,草本植物的物种丰富度随着海拔高度的增加先增加后下降.(4)沿海拔梯度森林群落的最大树高、最大胸径、平均树高和平均胸径等群落结构均呈单峰分布格局.(5)α多样性沿海拔梯度变化趋势与物种丰富度相似,但没后者明显.β多样性随海拔的升高而有所降低,在低海拔较高.(6)在调查的海拔范围内,海拔梯度是影响植物群落分布的主要因子,坡度坡向为次要因子,海拔比坡度坡向对群落的结构特征、物种丰富度以及(α、β)多样性的影响更大,而在局部尺度上,人为干扰以及小地形导致的生境异质性对群落物种多样性有着重要影响.

Eleven sampling plots were established along an altitudinal gradient in Mt.Wujin,and the vertical distribution pattern of plant community,species composition,and species diversity were studied by using quantitative classification.The results show that（1）with the increase of altitude,the forest communities were mixed forest of Chinese pine forest,side of Berlin,Chinese pine and arborvitae mixed,pine Prunus davidiana wild apricot,White pine,Chinese pine and Pinus bungeana mixed;（2）A total of13 kinds of trees,15 species of shrubs,and 31 kinds of herbs were recorded;（3）Unimodal distribution pattern of species richness is significant,and the biggest richness appears in the medium altitude.Woody plant species richness declined simultaneously with the increase of altitude,herbaceous plants of the species richness increased with the increase of altitude first and then declined;（4）With the increase of altitude,the maximum height,maximum DBH,average height and average DBH of trees all showed an increasing pattern,and then a decreasing pattern with the increase of elevation;（5）The change trends of α diversity along an altitudinal gradient are similar to species richness,but not the latter obviously.β diversity have a rising trend in low altitude;（6）Elevation within the scope of this study,elevation gradient are the main factors that affect the distribution of plant communities,slope to the secondary factors,on a local scale,human disturbance and habitat heterogeneity on small terrain have an important impact on species diversity.