淫羊藿分株种群特征及其与箭叶淫羊藿空间分布的点格局分析

Characteristics of the Ramet Population of pimedium brevicornum and Analysis of Spatial Point Pattern for brevicornum and sagittatum

对四川省南充市金城山3个不同海拔梯度(560 m、653 m、774 m)上的淫羊藿分株种群特征以及用聚块性指标(m*/m)、聚集指数、Cassie指标、扩散系数和点格局分析法,分别对淫羊藿基株种群与海拔771 m处箭叶淫羊藿基株种群的空间分布格局进行了研究.结果显示:在低海拔梯度560 m处淫羊藿分株种群密度达到最大,随着海拔的升高,淫羊藿分株种群密度显著减小.不同海拔高度下,淫羊藿分钻种群根冠比在774 m处最高.3种海拔梯度上,淫羊藿基株种群空间分布格局为集群分布;箭叶淫羊藿基株种群在尺度(t)0～0.01之间呈随机分布,在0.01～0.5之间呈集群分布.最后,结合保护淫羊藿和箭叶淫羊藿的药用资源以及点格局分析方法在研究草本植物种群空间分布格局中的优越性展开了讨论.

Epimedium brevicornum was sampled from Jinchengshan, a mountain of Nanchong, Sichuan province at altitudes of 560 m, 653 m and 774 m respectively for investigation of its ramet population variation. The results showed that the ramet population density decreased remarkably and its ratio of root to shoot increased with increasing elevation e.g, at 774 m the ratio of root to shoot was significantly higher than that at 560 m. The spatial distribution pattern of E. brevicornum at three different altitudes and E. sagittatum at the altitude 771 m were also investigated respectively with Congregation index （m^＊/m）, Clump index （Ⅰ）, Cnssie index （CA）, Dispersal index （C） and spatial point pattern analysis. The results revealed that the populations of E. brevicornum was clumped at all of the spatial scales, whereas the population of E. sagittatum was randomly distributed at the small spatial scales, and was clumped at the most spatial scales which ranged from O. 1 m to 5 m. Finally, we discussed the protection of E. brevicornum and E. sagittatum and advantage to use point pattern analysis in the investigation of the spatial pattern of herb plant.