Population structure and distribution pattern of Cycas bifida in Chongzuo of Guangxi

The population of Cycas bifida was investigated in Chongzuo，Guangxi. The population structure of C. bifida was analyzed by age structure and survivorship curve. The pattern of C. bifida was studied by using dispersal index，clump intensity，mean crowding，patchiness index，cassie index，etc. The results showed that the population dynamics belonged to growth type because there were lots of seedlings，and the population structure was relatively stable. It was found that the blooming plant was very few，only 5 in the population. There was no seeding plant. Spatial distribution pattern of C. bifida population conformed to clumped distribution，which closely related to its ecological and biological characteristics，as well as affected by its habitat heterogeneities.