Interspecific Association of Dominant Tree Species in Castanopsis carlesii Community with Different Regeneration Modes

A typical secondary forest community of Castanopsis carlesii was selected with different regeneration methods (artificial promoted regeneration,natural regeneration) in central Fujian,and the variance ratio was used to measure the overall connectivity,while χ² test was used to determine interspecific association. The interspecific association of dominant tree species was assessed using a combination of the Pearson correlation coefficient and Spearman rank correlation coefficient. The results showed that the overall correlation of 18 dominant species in Castanopsis carlesii artificial promoted regeneration forest and 16 dominant species in natural regeneration forest was negative correlation,not significant and the proportion of the significant species pairs of χ² test was less than that of Pearson and Spearman correlation analysis. The positive and negative ratio of correlation of χ² test for artificially promoted regeneration forest was 0.85,and that for natural regeneration forest was 0.69. The positive and negative ratio of correlation of Pearson and Spearman showed little difference,and most species pairs were negative correlation. The combination of the three methods suggested that the two stands were in the climax stage of immature succession. The three null model qualitative judgments based on the percentage of permutation similarity analysis,combined with the quantitative analysis of the DNCI index,showed that the construction of the Castanopsis carlesii community in two different ways of regeneration was dominated by dispersal processes. The comprehensive analysis results showed that the artificial promotion regeneration measures had a positive effect on the interspecific relationship of Castanopsis carlesii community,which could accelerate the development of community succession in the direction of stable coexistence of species. The tree species with significant positive relationship could provide reference for tree species configuration in forest management or ecological restoration.