栓皮栎人工林主要树种种群空间分布格局

The distribution patterns of dominant tree populations in Quercus variabilis plantation

为揭示连云港地区栓皮栎人工林主要树种的种群空间分布格局及其动态变化规律,根据群落调查资料,在计算树种种群的重要值的基础上,确定栓皮栎人工林的主要树种,并应用扩散指数、负二项参数、Lloyd的平均拥挤度、聚块性指标、Morisita指数对该人工林主要树种的种群分布格局进行分析。结果表明:连云港栓皮栎人工林主要树种为栓皮栎、盐肤木、黄檀和赤松,种群分布格局都为聚集分布,聚集强度表现为:栓皮栎种群<黄檀种群<盐肤木种群<赤松种群;在不同发育阶段,主要树木种群的聚集程度不同,栓皮栎种群聚集强度随种群龄级的增加而减小,而盐肤木种群和黄檀种群的聚集强度则随种群龄级的增加而增加;种群分布规律与种群个体数的大小和种群的生物学和生态学特性有关。可以进行适当的透光伐作业改善林内的光照条件,促进伴生树种的更新。

To study the spatial distribution patterns and variations of the dominant tree populations in a Quercus variabilis plantation in Lianyungang, the important values of tree species in the Quercus variabilis plantation were calculated based on the plot data, and the dominant tree species in the forest were determined. Some indexes such as David and Moore＇ s in- dex, negative binomial parameter, Lloyd＇s index, patch index and Morisita index were applied to analyze the distribution patterns of dominant tree populations in the Quercus variabilis plantation. The results indicated that the dominant tree spe- cies of Quercus variabilis plantation included Quercus variabilis, Rhus chinensis, Dalbergia hupeana and Pinus densiflora, and these dominant tree populations appeared an aggregation distribution pattern; meanwhile, for the same tree population, the aggregation degree of populations at different age stage was significant, the aggregation strength of Quercus variabilis populations decreased as the age stage increasing, but the aggregation degree of Rhus chinensis population and Dalbergia hupeana population increased respectively as the age stage increasing. It proved that distribution patterns of the dominant tree populations in the Quercus variabilis plantation were closely related to population size, biological and ecological charac- teristics. Release cutting could enhance the light condition and promote the regeneration of associated tree species.