Differed Bud Bank Dynamics of Phragmites australis in Heterogeneous Habitats in Zhalong Wetland

摘要

Bud banks play important roles in plant regeneration, especially after disturbances. Vegetative reproduction contributes greatly to the population maintenance of Phragmites australis, a worldwide helophyte, which is closely related to its bud bank dynamics. We studied bud bank dynamics of Phragmites australis during a whole growing season in two habitats (wet and aquatic) in Zhalong wetland. The current bud stock of this species in wet habitat was significantly higher than that in aquatic habitat (P < 0.05). Input rate of bud bank increased while germination rate decreased during the growing season. In all investigations, input rate and output rate of Phragmites buds were significantly higher (P < 0.05) in wet habitat than in aquatic habitat, whereas death rate and dormancy rate had the opposite trend (P < 0.05). In both habitats, dormancy rate decreased and germination rate increased with the increase of age class. Bud bank dynamics of Phragmites may have substantial effects on the aboveground populations, but we failed to find any significant relationship. Therefore, the responses of Phragmites bud bank and tiller population to physical stresses and disturbances, and their interactions need further study.