Abstract: We explored the interspecific association of main species and the coexistence mechanism of evergreen and deciduous species in Lushan National Nature Reserve of Jiangxi Province, aiming at providing scientific basis for biodiversity conservation and vegetation restoration. The variance ratio test, χ² test, association coefficient (AC) and Spearman’s rank correlation coefficient test were used to analyze the associations of 32 main species with high importance value. Meanwhile, the niche similarity and niche overlap of evergreen and deciduous species were mea-sured. The overall association was significantly positive among the main species. Results of the χ² test showed that 263 species-pairs were positive and 230 species-pairs were negative, while 3 species-pairs had no association. The ratio of positive and negative association was 1.143, with a rate of 27.42% passing significance test. Results of the Spearman’s rank correlation coefficient test showed that 222 species-pairs were positive and 274 species-pairs were negative and that the ratio of positive and negative correlation was 0.81 with a rate of 34.68% passing significance test. The AC value of species-pairs was relatively low, with 345 species-pairs ranging from -0.6 to 0.6 and accoun ting  for 69.56% of the total species-pairs. There were 110 species-pairs with positive correlation and 137 species-pairs with negative correlation between evergreen and deciduous tree species. The ratio of positive and negative correlation was 0.80 with a rate of 34.41% passing significance test. The degree of niche similarity and niche overlap was generally low, but there were some positively correlated species-pairs with large niche overlap. Together, our results suggest that the evergreen broad-leaved forest in Lushan Nature Reserve was at the later stage of stable succession. The loose interspecific association indicated that the distribution of species was relatively independent. Habitat selection, resource demand complementarity or mutualism were the main reasons for the coexistence of evergreen and deciduous species.

Key words: interspecific association, evergreen broad-leaved forest, niche, coexistence mechanism, Lushan Mountain.