Spatial pattern analysis and associations of different growth stages of populations of Abies georgei var. smithii in Southeast Tibet,China

Abies georgei var. smithii is an important plant species in Southeast Tibet, China. It has high ecological value in terms of biodiversity protection, as well as soil and water conservation. We analyzed the spatial pattern and associations of A. georgei var. smithii populations at different growth stages by using Ripley’s L function for point pattern analysis. The diameter structure was a nearly reverse ‘J’ shape. The amount of saplings and medium-sized trees accounts for a large part of the entire population, suggesting a high regeneration rate and an expanding population. In the transition from saplings to medium trees or to large trees, saplings show a significant aggregation distribution at small scales, while medium trees and large trees show a random distribution. There are significant inverse associations between saplings and medium trees and large trees at small scales, while there are no obvious associations between medium trees and large trees. The natural regeneration was affected by interspecific competition, and it was also affected by intraspecific competition. The joint effects of biological characteristics and environmental factors contribute to the spatial distribution pattern and associations of this A. georgei var. smithii population.