陕西府谷自然保护区杜松种群的空间分布格局及其动态

Spatial distribution patterns and dynamics of Juniperus rigida population in Fugu Nature Reserve of Shaanxi Province

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, 2.79 and 1.54 respectively. With diameter class increasing, patchiness index decreased gradually and clumping degree of population decreased, trees of diameter class Ⅶ 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.