Abstract:

Species composition, quantitative dynamics and effects of gap age and gap size on species compositions were studied in the tropical montane rain forest of Bawangling Natural Reserve, Hainan Island. The results show that the species compositions of gap fillers in tropical montane rain forest are complex and the individual numbers are not uniform among species. There are 116 species in 27 gaps, in which 10 species with larger individual numbers account for 43.03% of all individual numbers, but 58 species with few individual numbers only account for 6.02% of all individual numbers. Gap size makes significant effects on the species composition and number of seedlings; seedling individual density and seedling species density decrease with the increasing of gap size. Few differences are found in density of saplings and mature trees in different size gaps. Seedlings have visible higher individual density and species density in mature gaps than in young gaps and in middle age gaps. The transition rate of seedlings to saplings is higher in large and mature gaps than in small and young gaps. Tree species can be classified into 4 groups according to the quantitative dynamics of tree seedling in different gaps.

Key words: Tropical montane rain forest, Gap, Seedling bank, Hainan Island