Abstract:Based on the ecological niche space compartmentalization, the nutrition utilization status of the main arbor species of Castanopsis fabri community in different resource spaces in Daiyun Mountain Nature Reserve were studied by using their multidimensional niche breadth and their niche overlap rates. The results showed that the nutrition utilization of different species varied in different resource spaces, i.e. the niche breadths of the same species at different age class were different, and also did the niche breadths of different species at the same age class. There were 33 pairs of species with niche overlap rate ranged from 0.2 to 0.3, which acounted for 27.5% of the total species;and those of 51 pairs over 0.3 acounting for 42.5%. It revealed that the niche overlap rate of dominant populations was comparatively high with similar resources utilization ability, and the competition pattern among them was obvious. The niche overlap rate ranged from 0.042 to 0.424 between C. fabri and other species in tree layer, it indicated the competition to resource utilization between C. fabri and other species was low, and to some extent, it determined the population’s dominant place in the community. According to the classical layered frequency analysis, the C. fabri population belongs to the typical recession type of species, which is consistent with their actual community succession sequence.