Abstract: An investagationon the litter cover of a typical Leymus chinesis community in Grassland of Northeast China showed that, the litter had great effect on recovering of Leymus Chinesis in early spring: A certain amount of litter might shift the recovering of LeynZus chinesis; to an earlier date and encourage the growth of Leymus chinesis; However, too much or too little litter cover could delay the recovering of Leymus Chinesis.The number of species in community increased with the increase of litter thickness until having reached a peak value at 800g/m².The more similiar the thickness of litter cover was, the more similiar the similiar coefficients of species in two sample fields were, vice versa.Each quantitative character of the community such as density, height, coverage, aboveground biomass increased till a peak value and then decreased.The proportion fo Leymus chinesis in total aboveground biomass deceased with the increase of liitter thickness.

Key words: Leymus chinesis, Community, Littter, Quantitative character, Species

摘要： 通过对东北典型羊草群落枯草层的调查和观测,结果表明,枯草层对羊草早春的返青有一定影响。适宜的枯草层促使羊草提前返青,生长加快,而过厚和缺少时则使返青延迟。群落的物种数随着枯草层厚度的增加而增加,枯草层800g/m²达到峰值后有所下降,枯草层厚度的处理梯度越接近,样地间的物种相似性系数也越接近,反之相似性系数差异越大,群落的各种数量特征,如密度、高度、盖度、频度和地上生物量随着枯草层厚度的增加而增加,达到峰值后则逐步减少。羊草地上生物量占地上生物总量的比例随着枯草层的增厚而呈递减趋势。

关键词: 羊草, 群落, 枯草层, 数量特征, 物种数