Structure and distribution patterns of dominant populations in an evergreen broadleaved forest in north Guangdong Province.

Field data were obtained by sampling contiguous grid quadrat method in the 2 hm2 evergreen broadleaved forest permanent plot established in Chebaling National Nature Reserve,Shixing County,north Guangdong Province.Through analyses of dominant population structure,distribution pattern and niche characterislics,community dynamics and its underlying relations to the tree layer were discussed.The results indicated that 1) the most dominant tree species in the community was Castanopsis carlesii and the size-class distribution of the dominant species showed an L-shaped structure,showing that the community was in a growing and stable increasing period;2)as for the vertical distribution structure and niche breadth,it was found that Castanopsis carlesii and Schima superba,which were abundant in individuals and sapling reserves,had greater niche breadth and more superior in resource utilization.The resource utilization ability of some species including Neolitsea chuii and Styrax suberifolia were less,while Eurya acuminata was the least;and 3)the distribution pattern of dominant populations analyzed using t-test of variance to mean ratio,Lloyd's index and negative binomial parameter,were clumped as a whole.However,the distribution patterns changed from clumped into random with the time during development period,while the clumped intensity of different populations reduced gradually,which was not only closely related to ecological and biological characteristics of species,but also to its environment.