中亚热带南酸枣林优势种群的种间联结性

Interspecific associations of dominant plant populations in a mid-subtropical Choerospondias axillaris forest

基于方差比率法、χ~2检验、Pearson相关和Spearman秩相关检验对中亚热带南酸枣林13个乔木树种、14种灌木、16种草本植物的种间联结性进行定量研究。结果表明:乔木层、灌木层、草本层总体种间关系分别为不显著负关联、显著负关联和不显著正关联;χ2检验乔木层、灌木层、草本层均为负关联种对占较大优势,分别占总种对数的80.77%、80.22%和83.33%,正关联种对数次之,分别占总种对数的16.67%、18.68%和16.67%,无关联种对数为2对;Pearson相关检验乔木层有正关联种对41对、负关联种对37对、正负关联比为1.11,灌木层有正关联种对34对、负关联种对57对、正负关联比为0.60,草本层有正关联种对43对、负关联种对77对、正负关联比为0.56;Spearman秩相关检验乔木层有正关联种对40对、负关联种对37对、无关联种对1对、正负关联比为1.08,灌木层有正关联种对35对、负关联种对55对、无关联种对1对、正负关联比为0.64,草本层有正关联种对45对、负关联种对74对、无关联种对1对、正负关联比为0.61。

A number of statistic methods （variance ratio method, X2 test, Pearson＇ s correlation coefficient test and Spearman＇ s rank correlation coefficient test） were used to characterize inter- specific associations of 13 overstory tree species, 14 shrub species and 16 herbaceous species in a secondary natural forest of Choerospondias axillaris in mid-subtropical region at Qingyanghu Na- tional Forest Park, Hunan Province. The overall interspecific associations were non-significantly negative, significantly negative and non-significantly positive correlations among dominant plant populations in overstory, shrub and herbaceous layers, respectively. The X2 test showed that the species-pairs of negative correlation were dominant in the three layers, accounting for 80.77%, 80.22% and 83.33% of the total species-pairs in overstory, shrub and herbaceous layers, respec- tively; followed by species-pairs of positive correlation, which accounted for 16.67%, 18.68% and 16.67% in the three layers, respectively. There were few species-pairs of no correlations in the plant community. The Pearson＇ s correlation coefficient test showed that the number of spe- cies-pairs in positive association was 41, the number of species-pairs in negative association was 37, and the association ratio was 1.11 in overstory layer; the corresponding values were 34, 57 and 0.60, and 43, 77 and 0.56 in shrub and herbaceous layers, respectively. The Spearman＇ s rank correlation coefficient test showed that the number of species pairs in positive association was 40, the number of species pairs in negative association was 37, the number of species pairs innon-association was 1, and the association ratio was 1.08 in overstory layer; the corresponding values were 35, 55, 1 and 0.64, and 45, 74, 1 and 0.61 in shrub and herbaceous layers, respectively.