Interspecific relationships of Vitex negundo var. heterophylla community of Taihang Mountain in Shanxi Province

The interspecific association and correlation of 26 dominant species in Vitex negundo var. heterophylla community were analyzed by using x2test, Pearson's coefficient and Spearman's coefficient. The results showed that those dominant species composed 525 speciespairs; among these speciespairs, the extreme significant association or correlation were 5, 14, 15 respectively; and the significant association or correlation were 10, 6, 13, respectively. Speciespair, showing positive association or correlation, might have similar biological characteristics and similar ecoadaptability and niche overlapping. Speciespairs showing negative association or correlation might have different ecological characters, different adaptation and niche separation.