Numerical Analysis of Interspecific Relationship of Species of Community in Huangfuchuan Watershed

20 dominant species in Huangfuchuan watershed were analysed by X2 test,Pearson's correlation coefficient and Spearman's rank correlation coefficient test.The results indicated that:positive association coefficients of 31 species-pairs for the X2 test were significant(p0.05) or highly significant(p0.01),and negative association coefficients were significant or highly significant in 27 other species-pairs;In Pearson′s correlation coefficient test,16 species-pairs had positive relationship,and 13 species-pairs had negative relationship;In spearman′s rank correlation coefficient test,there were positive relationship between 36 species-pairs and negative relationship between 27 species-pairs.The results showed that dominant species have interspecific relationships and independent distribution pattern.Based on the results,20 species in the community were divided into three ecological groups.