松嫩平原硬拂子茅无性系种群营养繁殖的数量特征

Quantitative Characteristics of Vegetative Propagation of Calamagrostis Clonal Populations in Songnen Plain of China

硬拂子茅是典型的无性系禾草，分蘖节存活时间最多为４年。割草场和放牧场硬拂子茅无性系种群分蘖株均属于增长型年龄结构。家畜采食能促进２、３龄分蘖株的形成与存活。１龄级分蘖株的生产力明显高于２龄级。根茎的存活时间最多为３年。根茎的物质贮存能力以１龄级最大，随着龄级的增加不断减小。放牧扰动对硬拂子茅无性系种群各龄根茎的养分贮藏均有不利影响。割草场和放牧场硬拂子茅潜在无性系种群均属于增长型的年龄结构。

Calamagrostis rigidula is a typical clonal grass, with its tiller nodes kept alive as long as for 4 years. The age structures of the tillers of the grass on both pastures for grazing and cutting uses are of an expanding type. Grazing can stimulate the formation and survival of two year and three year old tillers. The productivity of one year old tillers is obviously higher than that of the two year old class. Rhizomes of the grass can live at most for three years, and the storage of dry matter within them is the highest for the one year old class and it decreases with an increased plant age. Grazing disturbance has an adverse effect on the nutrient storage within rhizomes of all age classes. On both pastures for grazing and cutting utilisation the age structrue of potential clonal populations of the grass is also of an expanding type.