Abstract:

The effects of gap size and coverage of dwarf bamboo, Fargesia nitida, on structure and spatial pattern of the seedlings of Abies faxoniana,Betula utili and Acer caudatum var.prattii in gaps of Abies faxoniana forest were examined in Wolong Giant Panda Nature Reserve, Sichuan Province. The gaps (≤50 m²,50～150 m² and >150 m²) were selected, there are 3 F. nitida coverage(20%, 20%～50%and >50%) in each gap area type. The results showed: 1) The seedlings of the three dominant species were few in gaps with highest coverage of bamboo. After gap formed, F. nitida inhabited the most gaps, there were significant differences in number of seedlings of all and A. faxoniana among the gaps with different bamboo coverage (p<0.05); 2) The influence of bamboo coverage on seedlings density of A. faxoniana was more obvious than those of B. utilis and A. caudatum var. prattii for the reason of different ecological characters among the three species. A. faxoniana is shade-tolerant species, which firstly regenerated on the area with no or few bamboo existence; 3) The spatial analyses revealed that all seedlings in different gaps were nearly clumped at varied spatial scales, which was caused by not only the biological characters of different tree seedling but also gap environment. We concluded that the combined effect of gap size and bamboo cover would influence the density, structure and spatial pattern of the tree seedlings.

Key words: Fargesia nitida, gap, seedling, spatial pattern, Abies faxoniana forest