Impacts of bamboo dominance and die-off on seedling dynamics in a tropical secondary forest (Brazil)

Aulonemia aristulata is a tropical bamboo species of mixed rhizome type and monocarpic flowering that can become super-dominant after anthropogenic disturbances in tropical forests. The synchronized reproductive events of flowering and die-off of monocarpic bamboo systems provide a rare opportunity to evaluate the temporal effects of bamboo dominance on forest regeneration. To evaluate the effects of bamboo dominance on forest regeneration, we compared the structure (abundance, richness, composition) and dynamics (mortality, recruitment, survival and growth) of tree and shrub seedling communities from two non-contiguous forests stands (bamboo-dominated vs. non-dominated sites) for 2 years, before and after a synchronized reproductive event. Bamboo dominated plots had higher abundance, floristic richness and recruitment of tree and shrub seedlings when compared with bamboo non-dominated plots. Bamboo die-off did not represent an opportunity to improve establishment and investment in the vertical growth (height) of seedlings in bamboo-dominated plots. We postulate that the mode of rhizome extension seen in bamboos might be a consistent trait determining the spatial pattern of occupation and population structure and thereby playing a fundamental role in the pattern of native tree community establishment after bamboo die-off. The formulation of a management approach is necessary in order to better understand the biological traits of bamboo species and their influence on the spatial pattern of occupation and population structure. Additionally, this influence may differently impact restoration and definition of management practices, including the need for direct intervention by manually controlling bamboo cover following die-off to promote and maintain seedling establishment and diversity.