植被状况对乔木幼苗物种多样性的影响

EFFECT OF VEGETATION STATUS ON SPECIES DIVERSITY OF TREE SEEDLINGS IN A SUBTROPI CAL EVERGREEN FOREST

摘要:

运用灰色关联度分析亚热带常绿阔叶林植被状况对乔木幼苗物种多样性的影响。结果表明，所选取的植被状况参数对乔木幼苗物种多样性有不同的影响，对乔木幼苗物种多样性影响较大的是草本层的Simpson指数、灌木层Simpson指数和灌木层盖度，影响较小的为草本层盖度和灌木层Shannon-Wiener指数。乔木幼苗4个物种多样性指数受植被状况影响的顺序为：Pielou均匀性指数＞Shannon-Wiener指数＞物种丰富度指数＞Simpson指数。草本层、灌木层和乔木层对乔木幼苗的物种多样性有不同的影响，其影响方式也不一样。

Abstract:

Grey correlation analysis was used to study the efects of vegetation status on species diversty of tree seedlings in a subtropical evergreen forest in Dujiangyan (Sichuan Province)．Twenty-two plots with 5 m×5 m each in a sample site of 10 m×55 m were investigated． Data obtained included plant species，number of individuals，plant height，diameter at breast height，and canopy coverage in tree layer；plant species density and coverage in shrub and herb layers；and species, individuals and plant age of tree seedlings above 13 m．Species abundance index (S)，Simpson index (D)，Shannon-Wiener index (H), and Pielou evenness index (E) were used in α-diversity analysis. The results indicate that the parameters of vegetation status affecting species diversib, of tree seedlings are greater in D in herb layer, and H and coverage in shrub layers；but less in H in shrub layer an dcoverage in herb layer．The effect of vegetation status on the four species-diversty indexes are in the order Pielou evenness index>Shannon-Wiener index>species abundance index>Simpson index．