Interspecific relationship of woody plants in Quercus wutaishanica community in Wulu Mountain Nature Reserve, Shanxi Province of China: A quantitative analysis

Based on 2 × 2 contingency table, and by using quantitative analysis methods, this paper studied the interspecific relationship among 351 species pairs of 27 dominant woody species in Quercus wutaishanica community in Wulu Mountain Nature Reserve. Variance analysis showed that the interspecific correlation of the 27 dominant populations was not significant, and the distribution of the species was relatively independent. The χ2 test showed that among the 351 species pairs, 154 pairs were positively while 188 pairs were negatively correlated, and the correlation ratio was 0.82. Pearson’s correlation coefficient test showed that 124 pairs were positively while 226 pairs were negatively correlated, and the correlation ratio was 0.55. Spearman’s rank correlation coefficient test showed that 151 pairs were positively while 200 pairs were negatively correlated, and the correlation ratio was 0.76. Compared with χ2 test, the Pearson’s correlation coefficient and Spearman’s rank correlation coefficient tests had higher sensitivity. For vast majority of the 351 species pairs, their interspecific relationship did not reach significant level, indicating that the Q. wutaishanica community in Wulu Mountain Nature Reserve was of obviously secondary succession. According to the adaptation to the environment and the leading ecological factors, and assisting with principal components analysis, the 27 dominant populations were divided into three ecological species groups.