Inter-Specific Correlations among Dominant Populations of Woody Syringa reticulata Communities in Wulu Mountain Nature Reserve,Shanxi Province of China

We selected 34 dominant species according to frequency and studied interspecific associations and correlations using variance ratio(VR) analysis of the overall association and χ2-test,Pearson correlation coefficient and Spearman rank correlation coefficient based on 2 ×2 contingency tables of species presence/absence data.No significant negative correlations were observed among the 34 dominant species,which suggested that the forest was not stable.Interspecific correlations among 561species-pairs of the 34 dominant species showed that 216,149 and 206 species-pairs were positively correlated,345,412 and 365 species-pairs were negatively correlated,and the positive and negative correlation ratios were 0.626,0.362 and 0.564,based on χ2-test for 2 ×2 contingency table.Spearman rank correlation was more sensitive than the Pearson correlation.