Abstract: With the plant communities in four (15, 30, 60 and 160 years) successi on series of evergreen broad-leaved forest in Daming Mountain of Guangxi as tes t objects, this paper studied the dynamic changes of the importance value, niche breadth, and niche overlap of dominant populations in the process of succession. The results showed that Cunninghamia lanceolata, Castanopsis fabri, Huodendro n biaristatum, and Beilschmiedia fordii were the dominant populations in t he commu nities of the four succession series, respectively. These populations had the wi dest niche breadth, and played important function. In each succession series, th e species with wider niche breadth had larger niche overlap among themselves and with other species. The species with lower importance value but wider niche bre adth might become the dominant species in the next succession series. Some speci es had narrower niche breadth but larger niche overlap, due to the habitat fragm entation and spatial heterogeneity. In the whole succession series, the mean val ues of populations niche breadth and niche overlap all decreased gradually at ea rlier succession stages but increased slightly at the latest stage, suggesting t hat with the development of succession, the species competition and the changes of natural resources led to a definite niche differentiation, decrease of niche overlap, and formation of stable community structure.

Key words: Environmental carrying capacity, Quantificational method, Perspective