Two Phragmites species, Phragmites australis (Cav.) Trin. and Phragmites japonica Steud., have drawn public attention worldwide as a plant material for waterfront revegetation and riparian buffer zone. These plants have excellent functions in cleaning water quality, preventing soil erosion in addition to offering various habitats for wild animal communities, fishes, birds and mammalia. However, sites where Phragmites australis and Phragmites japonica are planted often suffer from disturbance of erosion, sedimentation and lodging, etc. In this study, therefore, growth response to lodging of Phragmites australis and Phragmites japonica was examined as one of the disturbance. As the results, lodging tolerance of Phragmites japonica was higher than Phragmites australis. In addition, it was also proved that the disturbance and bare field formation by river water itself was the most important factor in promoting epigeal stolon elongation and establishment of Phragmites japonica. Therefore, for creating stable waterfront vegetation and riparian buffer zone using Phragmites species, Phragmites japonica is preferable for strand line with frequent disturbance, while Phragmites australis is preferable in the hinter-field with little disturbance.
