Abstract:In order to understand the community structure of Castanopsis hystrix and Acacia mangium broad-leaved mixed forest in Longyandong Forest Farm in Guangzhou, its species diversity was analyzed. The results showed that the species richness was in the order of tree layer > shrub layer > herb layer > interlayer plant layer. The Simpson and Shannon-Wiener indices of tree layer were 0.945 and 0.237, respectively, with the density of 2 671 ind./hm2. Castanopsis hystrix, A. mangium, Melicope pteleifolia, Triadica cochinchinensis and Acacia confusa had high importance values of 12.79%, 10.98%, 8.08%, 7.78% and 7.02%, respectively. Among the 35 shrub species, the important values of Litsea rotundifolia var. oblongifolia (14.95%), Psychotria asiatica (12.60%) and Cratoxylum cochinchinense (10.17%) were more than 10%. The dominant family of interlayer speciess was Rubiaceae, followed by Apopynaceae. The density of herb species was about 38 000 ind./hm2, and Poaceae was the dominant family, which consists of 9 species. Castanopsis hystrix community was transited from young age to middle age, the dominant population was growth type, while Acacia mangium community was transited from near maturity age or mature age to over maturity age. Compared with similar forests in different region, the biodiversity of mixed forest was much higher than that of pure forest. Therefore, C. hystrix-A. mangium broad-leaved mixed forest had formed the structure of mixed multilayer and different age forest with high species richness in tree layer, shrub layer and herb layer.
