DYNAMICS OF ASSOCIATIONS BETWEEN TREE SPECIES IN A SECONDARY TROPICAL MONTANE RAIN FOREST AT JIANFENGLING ON HAINAN ISLAND

The pattern of association of tree (DBH7. 0 cm) species was examined in forty-eight 10 m X 5 m permanent plots during 10 years of succession in a secondary-growth tropical montane rain forest at Jianfengling on Hainan lsland using the variance test and 2 X 2 contingency table methods. Field observations commenced in 1989 when the forest was 25 years old. Three hypothesies were tested concerning the dynamics of species interactions through succession and the following results were obtained. 1)The variance test reveals that all tree species in the forest showed a non-significant pattern of positive association. The observed index of species association (V) ranged from 1. 00 to 1. 21 (close to V= 1 under the null hypothesis of no association) over the 10 years of succession suggests that tree species were mostly independently distributed. 2) The proportion of species pairs showing positive and negative associations compared to those showing no associations declined with time. In addition, while the level of significance of negative associations remained unchanged, that of positive associations declined with time. 3) No negative associations were found between the early-established species (pioneer or canopy species) and the later invading species (tolerant or subcanopy species), or between the later invading species. All positive associations between the early-established species and the later invading species were not significant, while those between the later invading species were significant.