おhragmites communis is a typical species of clonal plant and its natural population is mainly renewed by the vegetative propagation of rhizomes. In the Songnen Plain in China, the secondary tillers can develop from basic internode buds of the main tillers only when its top is removed. The longest life time of the rhizome is six years. The great mass of rhizomes begin die from the fifth age class. The rhizomes in the sixth age class only take small proportion in the age classes. Accumulation of the dry matt...