Abstract: The species component and their community roles of the artificial grassland of Elymus sibiricus changed much with increasing utilization years, and the invasive weeds species also increased, but relative biomass, density and coverage of Elymus sibiricus decreased; to the invasive weeds, the results were reversed. The important value index of Elymus sibiricus declined sharply with utilization years, the status degraded from absolute d ominance on the second and the third year to minor dominance on the ninth year; and the invasive weeds was in dominance on the fifth and sixth year. Species diversity and homogeneity increased as the degradation succession processed, and community dominance decreased.

Key words: Elymus sibiricus, Structural characteristics of a community, Invasive weeds species

摘要： 老芒麦生物学特性及群落结构特征随着利用年限的增加而发生明显的变化。结果表明,入侵植物种数随着利用年限的增加呈逐渐增加的趋势。老芒麦在草地群落中相对生物量、相对多度和相对盖度随着利用年限增加而明显下降,而入侵植物相对生物量、相对多度和相对盖度则明显增加。老芒麦的重要值随着利用年限的增加而急剧降低,老芒麦在利用的第2、3年占绝对优势,在第5、6年入侵植物占重要地位,到第9年才逐渐沦为次重要地位。老芒麦的草地物种多样性指数和均匀性指数随着利用年限的增加而逐渐增加,而生态优势度则逐渐降低。

关键词: 老芒麦, 群落结构特征, 入侵植物