Abstract:

Point pattern analysis of species in a community is important in gaining a better understanding of the underlying ecological processes controlling the observed structure. In this paper, univariate and bivariate spatial point pattern analysis based on the pair-correlation function were used to evaluate the spatial patterns of Quercus variabilis. We compared the spatial patterns and associations of Q. variabilis at four different growth stages, and the relationships between standing trees and snags of Q. variabilis in two fully-mapped 1-ha forest plots in the Baotianman National Nature Reserve. We found that: (1) Aggregation was the main pattern type of Q. variabilis in the plots, with one plot showing stronger aggregation and the other exhibiting more randomness. (2) At different growth stages of Q. variabilis in the two plots, aggregation was found in younger stages and randomness in the older. (3) Positive interactions were found between the different growth stages of Q. variabilis in Plot I, and negative interactions in Plot II. (4) There are positive associations between standing trees and snags of Q. variabilis in Plot I, and spatial segregation in Plot II. Our study suggests that the spatial distribution of Q. variabilis may be influenced by environmental heterogeneity. This is important because the spatial distribution of this species in turn affects self regeneration of Q. variabilis populations in Baotianman National Nature Reserve.

Key words: spatial pattern, Quercus variabilis, Baotianman National Nature Reserve