Interspecific Relations of the Dominant Plant Populations at Mt. Jincheng, Sichuan, China

Methods of χ2-test for 2×2 contingency table, Pearson correlation coefficient test and Spearman rank correlation coefficient test were used to study the interspecific correlations among 276 species pairs of 24 dominant plant populations at Mt. Jincheng. The result showed that 15, 23 and 24 species pairs were positively correlated, while 3, 1 and 5 species pairs had negative correlations, and the ratios of positive and negative correlations were 5.0, 23.0 and 4.8. The proper conclusion of this study depended upon the proper combination of the χ2-test with Ochiai association index. Compared with Pearson correlation coefficient test, Spearman rank correlation coefficient test was more sensitive. According to the adaptability to the environment and the relationships between plants and environment, 24 species were divided into four ecological species groups and the different species in the same ecological species groups showed a positive association and correlation, which indicated that they had similar resource-utilizing ways and ecological requirements, while the negative association and correlation occurred among the species had different biological features, e.g., different adaptabilities to habits or segregated niches in some degree. Those species including Alnus cremastogyne, Carpinus funebris, Rubrs coreanus, Caytatia japonica and Smilax mucrophylla were found independently distributing. Fig 4, Tab 4, Ref 19