Abstract: The spatial heterogeneity of species diversity in dry south-slope of in North Mountain of Hebei was studied by Geostatistics method. The results show that the richness index,Simpson diversity index,Shannon-Weiner diversity index and Pielou evenness index were in normal distribution,and the coefficient of variation (CV) ranged from 11.1% to 27.7%,suggesting a moderate variability. The variogram of four diversity indices can be well fitted to the exponential model. Pielou evenness index behaved obvious anisotropy,and other 3 indices showed isotropic spatial correlation. The variable range of richness index is 84 m,so the distance between the plots used to investigate species biodiversity should be over 84 m to eliminate the plots correlation. Within the variable range,the structural factors were dominant for the spatial variation of 4 indices,ranging from 50.1% to 67.6%,suggesting that environmental factors are the dominant factors determine the spatial distribution of species diversity. Spatial distribution of 4 indices were characterized by strip and patch,and they decreased from up slope to down slope vertically,and the west was higher than the east in richness horizontally.

Key words: Species diversity, Spatial heterogeneity, Variogram, South-slope

摘要： 采用地统计学方法对冀北山地干旱阳坡草本植物物种多样性的空间异质性进行了研究。结果表明，丰富度指数、Simpson指数、Shannon-Weiner指数和Pielou均匀度指数均服从正态分布，变异系数CV为11.1%~27.7%，均属中等变异性；4个多样性指数的变异函数均为指数模型，丰富度指数、Simpson指数、Shannon-Weiner指数具有中等强度的各向同性空间相关性，Pielou均匀度指数具有明显的各向异性特点；丰富度指数的变程为84 m，在对该地区山地植被进行多样性调查时，样地之间的距离应在84 m以上，以消除取样时样地间的相关性；在变程范围内，各物种多样性指数空间变异的结构性因子占主导地位，所占比例为50.1%~67.6%，环境因素是决定物种多样性空间分布的主导因素；4个多样性指数在空间上均呈条带状及斑块状分布，垂直方向上，4个多样性指数在从上坡到下坡的环境梯度上呈逐渐下降的趋势，水平方向上，丰富度指数总体上西部明显高于东部。

关键词: 物种多样性, 空间异质性, 变异函数, 阳坡