采用方差/均值比率法和5个聚集度指标研究了陕西府谷自然保护区杜松(Juniperus rigida Sieb.etZucc.)种群15个样地的空间分布格局及动态特征。结果表明,杜松种群的空间分布格局为聚集分布,其v/m值、负二项参数、聚块性指数、丛生指数、平均拥挤度和Morisita指数分别为1.98、1.84、1.54、0.98、2.79和1.54。随着径级的增大,聚块性指数逐渐减小,种群的聚集程度也减小,Ⅶ级大树呈随机分布,该种群表现出明显的扩散趋势。调查发现,人为干扰对杜松种群的空间分布格局有较大影响。 

Spatial distribution patterns and dynamics of fifteen plots of Juniperus rigida Sieb.et Zucc. population in Fugu Nature Reserve of Shaanxi Province were studied by using methods of variance/mean ratio and five clustering indexes. The results showed that spatial distribution patterns of J. rigida population were clumping, and v/m ratio, negative binomial parameter, patchiness index, clumping index, mean crowing index and Morisita's index were 1. 98, 1. 84, 1. 54, 0. 98, 2. 79and 1. 54 respectively. With diameter class increasing, patchiness index decreased gradually and clumping degree of population decreased, trees of diameter classⅦ distributed randomly, so the population emerged obvious spreading trend. It is concluded that human disturbance can effectively affect spatial distribution patterns of J. rigida population.