Interspecific Association among Dominant Species in Acanthopanax senticosus Communities in Beijing, China

To clarify the species composition and interspecific association of Acanthopanax senticosus communities in Beijing, we carried out a series of typical sampling investigations. Based on the 2 × 2 contingency table, we used variance ratio (VR), χ²-test, Pearson's correlation and Spearman's rank correlation to analyze the interspecific association among 27 dominant species in A. senticosus communities. Results showed that 27 dominant species were significantly positively correlated, indicating a relatively stable succession status in the communities. The χ²-test, Pearson's correlation and Spearman's rank correlation analyses among the 351 species-pairs of the 27 dominant species showed that 191, 112 and 170 species-pairs were positively correlated, 160, 239 and 181 species-pairs were negatively correlated, and the positive and negative ratios were 1.19, 0.47 and 0.94, respectively. According to the species adaptations to the environment and the leading ecological factors, in combination with principal components analysis, the 27 dominant species were divided into four ecological species groups. The results showed high interspecific association among the A. senticosus communities. The communities also showed relative stability in species composition and development of community structure.