Characteristics of the Ramet Population of Epimedium brevicornum and Analysis of Spatial Point Pattern for E. brevicornum and E. sagittatum

Epimedium brevicornum was sampled from Jinchengshan , a mountain of Nanchong , Sichuan province at altitudes of 560m, 653 m and 774m 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)、Cassie 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 0. 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 .