松嫩平原蒙古蒿无性系种群结构的研究

蒙古蒿为根茎型多年生草本菊科植物。在生长季后期，分株在根颈处产生两种芽越冬，翌年根颈芽和根茎顶端芽均可发育为分株。通过对蒙古蒿的研究，创建了按根茎芽的繁殖世代数划分根茎型多年生草本菊科植物种群无性系分株的年龄及鉴别方法，以及用不同世代成员的数量配置来分析草本植物种群分株的年龄结构。龄级的划分标准是；由根茎顶端芽形成的分株为营养繁殖一代，作为1供级；1龄级分株死亡后，由根颈芽第1次萌生向上生长的分株为营养繁殖二代，作为2龄级；2龄级分株死亡后，由根颈芽第2次萌生向上生长的分株为营养繁殖三代，作为3龄级。鉴别时，如果分株顶端受损发生在根颈区以上的任何分枝均仍为原龄级，而不为下一个世代的龄级；如果根颈区有2个以上的芽同时萌生向上生长成株，则划分为同龄级。蒙古蒿的根茎芽最多可营养繁殖3个世代，根颈的生活年限最多为4年。在松嫩平原割草场，蒙古蒿种群进入开花期以后，种群由营养分株和生殖分株组成。各分株组分均有3个龄级，其数量和生物量均呈增长型年龄结构。生殖分株的生产力是营养分株的4—7倍。蒙古蒿芽库的潜在种群呈增长型年龄结构。分株根颈的繁殖潜力以1龄级最大，随着龄级的增加依次减弱。如果环境条件有利，蒙古蒿种群将以每年10cm的速度扩展种群的生态位空间。

Structures on the clone populations of Artemisia mongolica in the Songnen Plains in China

Artemisia mongolica(Ficsh.ex Bess)Nakei, is a species of perennial herbaceous rhizome plant of Conpositae.The two kinds of buds formed form ramet root crowns during later growth season could survive over the winter, and the buds of the root crowns and the rhizome apex developed to produce new ramets next year. A method of indentifying age classes of ramets was put forward, which was differentiated by propagation generation number of rhizome buds. The age structure of ramets was a quantity collocation of different generent generations within populations. The best rhizome buds had vegetative propagetion for three generations. and the root crowns might live less than four years. During flowering phase, the population was composed of vegetative and reproductive ramets in songnen Plains. There were three age classes for every rament component. and rament quantity and biomass changed in and expanding age structure. The productivety of reproductive ramets was 4~7 times than thag of the vegetative ramets. As the potential population. the buds had an expanding age structure. The age class one of the ramets was the strongest, in propagation potential of the root crowns and decreased gradually with the in-creasing of age classes. Under favourable environments, the populations could extend its niche space by the speed of 10 cm per year.