Abstract: In 2003 and 2006, investigations were made on the age structures of Spodiopogon sibiricus populations as well as the matter productivities and vegetative reproduction capacities of different age-class modules of the populations on the weedy meadow and elm woodland in Songnen Plain of Northeast China. At the two habitats, the tillers of S. sibiricus all consisted of 2-3 age classes, and the rhizomes all composed of 4 age classes. Both the tillers and the rhizomes had the greatest proportion of 1- or 2-year-old, and the age structures were of expansive or stable. The 1- or 2-year-old  tiller-node buds were dominant, and the rhizome topmost buds occupied 29.4%-45.0%, being of significance to the population regeneration in the next year. The 1- or 2-year-old  modules of the tillers and rhizomes had the highest matter productivity and vegetative reproduction capacity, and the rhizomes had higher vegetative reproduction capacity than the tiller-nodes.

Key words: meadow, elm woodland, Spodiopogon sibiricus, population, age structure