Abstract: A total of one hundred and twelve 10 m×10 m quadrats were set up in ten terrestrial secondary forest communities of Zhuhai City, Guangdong Province to study the niche breadth and niche overlap of the dominant plant species. The results indicated that the Shannon-Wiener’s niche breadth and Levins’s niche breadth of 23 dominant species in the communities were 0.4049—0.7736 and 0.0551—0.3086, respectively. The species with larger niche breadth were Acronychia pedunculata, Gordonia axillaris, Aporosa dioica, Microdesmis casearifolia, Gironniera subaequalis, and Sterculia lanceolata, which were the widespread species in natural forests. The niche similarity of dominant species varied between 0 and 0.3810, and the highest one occurred between A. dioica and Cinnamomum burmanii. A. pedunculata had different degree niche overlaps with other 22 species, but G. axillaris only had niche overlaps with a few dominant species. There were no niche overlaps in 20.6% of species-pairs. It was suggested that some widespread and well-adapted species with larger niche breadth, e . g . , A. pedunculata, G. axillaris, G. subaequalis and Endospermum chinense, should be selected in prior in the restoration of natural forests and the reconstruction of plantations.

Key words: Paddy soil, Fixed ammonium, Seasonal variation, Bioavailability, Hunan Province