Abstract

Effects of dwarf bamboo, Fargesia nitida, on micro-environments, species diversity and regeneration on the floor were investigated at three conditions, high density (HB), low density (LB) and without F. nitida (UB) in a subalpine Abies faxoniana forest, southwest China. Relative photon flux density (RPFD) on the floor became unfavorable, and physical and chemical features of soil improved with the density of F. nitida. Thickness of litters increased and bryophytes decreased with the density of F. nitida. Dominance of A. faxoniana in shrub layer, understory species diversity and trees regeneration were lowest in HB, however, which showed little significant differences in UB and LB. RPFD under bamboo layer and surface soil conditions (thickness of litters and bryophytes etc.) resulting from different bamboo density were significantly correlated with understory species diversity and A. faxoniana regeneration. High density of bamboo has a fatal influence on understory species diversity and tree regeneration. However, there is not a significantly negative effect of low density bamboo (< 10 culms/m²) in our study. Therefore, dynamics of bamboo density (flowering or by gap disturbance etc.) can provide useful guidelines for understanding understory species dynamics and regeneration of subalpine forest in this region.

Key words: Fargesia nitida, dwarf bamboo, micro-environments, tree regeneration, understory species diversity.