Interspecific Association Analysis of Dominant Tree Species of Rare and Endangered Plant in Keteleeria fortunei var. cyclolepis Community

Abstract:

The correlations of dominant tree species of Keteleeria fortunei var. cyclolepis community in Junzifeng Nature Reserve, Fujian Province were analyzed by using 2×2 contingency table, variance ratio (R_v), x²-test, Pearson correlation coefficient test and Spearman rank correlation coefficient test, and the ecological species groups were divided based on principal component analysis (PCA). The results showed that there was not significant negative correlations existed among the 21 dominant tree species, and Keteleeria fortunei var. cyclolepis had not significant association with other species. Among 210 species pairs, 110 species pairs were positively correlated, 81 species pairs were negatively correlated, and 19 species pairs were unrelated, with a positive-negative ratio of 1.36. Most species pairs were not significantly correlated each other, and the significantly correlated rate was only 0.48%. The results of Pearson and Spearman rank correlation coefficient test were similar. The number of negative correlation species pairs was greater than that of positive correlation species pairs, and most species pairs were not significantly, and the significantly rates were 6.19% and 7.14%, respectively. Compared with x²-test, the other two test were more sensitive. The dominant tree species could be divided into four ecological species groups by PCA two-dimensional sequence. The ecological habits and resource requirements of species in the same group were similar, most of them were positively correlated, and interde-pendence coexisted. There was a negative correlation among species in different ecological species groups, and species pairs competed with each other. The interspecific association of dominant tree species of Keteleeria fortunei var. cyclolepis community was relatively non-significant, and most species were independently distributed. The seedlings were difficult to renew, saplings face greater competitive pressure, and population size is gradually shrinking trend. In order to promote the normal growth and regeneration of Keteleeria fortunei var. cyclolepis population, the seedlings should be protected.