Spatial distribution pattern and correlation analysis of Cyclobalanopsis glauca dominant population in karst hills of Guilin

Abstract

The spatial distribution pattern of population is an important means to describe population characteristics, interspecific interactions, and the relationship between population and environment. Cyclobalanopsis glauca is a constructive population of climax community in karst ecosystems, in order to further understand the spatial distribution pattern of its populations, according to the sample plot investigation specification, a sample plot of 60 m × 60 m was set up, and the woody plants in the plot were spatially located and investigated for each tree. The C. glauca population was divided into three different diameter classes in the study, belonging to seedling (DBH<2 cm), sapling (2 cm≤DBH<10 cm), adult tree (10 cm≤DBH). Using the point pattern analysis method, g (r) and L12(r) functions based on Ripley’s K function were used for the analysis of the spatial distribution pattern and correlation analysis of C. glauca population in different diameter classes. The results were as follows: (1)The diameter class structure of C. glauca population was in an inverted “J” type distribution. (2) On the small scale, the stage of seedlings, saplings and adult trees, the spatial distribution pattern tended to cluster distribution，and the saplings, adult trees tended to random distribution on the medium and large scales. (3) The performances of spatial correlation between different diameter classes were different, the seedlings and saplings were positively related on the scale of 0-15 m; saplings and adult trees reflected on the scale of 0-10 m were no correlation, and there was a positive correlation on the scale of 10-15 m; seedling and adult trees reflected on the scale of 0-2 m were no correlation, and there was a positive correlation on the scale of 2-15 m. Therefore, the spatial distribution pattern and correlation of C. glauca population in the karst area of Guilin change with the spatial scale and development stage, which was the result of the combined effects of the population’s biological characteristics, intraspecific and interspecific relationships, and environmental conditions. The results of the study can provide basic information for the formation and maintenance mechanism of plant community and resource utilization research of karst hills.

Keywords

• cyclobalanopsis glauca population
• diameter class
• spatial point pattern
• spatial correlation
• karst hills