羊草人工草地群落演替动态研究

The Dynamics Study on Community Succession Artificial Grassland of Leymus chinensis

在退化羊草草原上耕翻播种羊草（Ｌｅｙｍｕｓｃｈｉｎｅｎｓｉｓ）后，植物群落演替动态与群落特征变化规律的研究结果进行了报导．通过对１９８４～１９９５年野外实地观测所得数据进行分析，结果如下：羊草人工草地经过１３年的演替群落丰富度（ｒｉｃｈ－ｎｅｓｓ）有所增加，种类组成出现差异．群落密度和地上生物量都为中期较高的峰型变化规律．群落的多样性指数和均匀性指数在后期有明显增加．羊草的重要值为前期迅速增加，中期相对稳定和后期下降的变化规律．１３年的演替过程可划分为三个阶段：前３年（１９８３～１９８５）为羊草种群的增长阶段，群落组成为羊草十一、二年生杂类草群落；随后５年羊草种群处于绝对优势且相对稳定的地位，群落组成为羊草＋冰草（Ａｇｒｏｐｙｒｏｎｍｉｃｈｎｏｉ）＋多年生杂类草群落，此阶段也是羊草草地的最佳阶段；第三个阶段为后５年（１９９１～１９９５）此阶段羊草在群落中的作用减弱，多年生植物种类和数量有所增加，群落组成为羊草＋冰草、变蒿（Ａｒｔｅｍｉｓｉａｃｏｍｍｕｔａｔａ）、阿尔泰狗娃花（Ｈｅｔｅｒｏｐａｐｕｓａｌｔａｉｃｕｓ）＋丛生小禾草群落．羊草人工草地正向天然羊草草原群落演变。

 An analysis study on dynamics succession and characters of community in degenerated steppe of L.chinensis (steppe of Artemisia frigida) which planted L.chinensis for restoration from 1984 to 1985.The results showed that species richness per unit area (20 m2) was increased and the main component species in the community was changed.The density and biomass increased after planted (1984￣1985).There is a peak value after planting L.chinensis during the forth to eighth years and then decreased.Diversity index and evenness index increased obviously during the course of succession.Importance value of L.chinensis have increased obviously (1983￣1985) and have a peak value during the forth to eighth years (1986￣1990),then decreased after ninth years.The process of succession of community may be devided into three stages.The first stage is community of L.chinensis+short Lived plant (1￣3 years after planting);The second stage is community of L.chinensis+A.michnoi+perenial plants (4￣8 year);The thrid stage is community L.chinensis+A.michnoi.A.commutata+grass(9￣13 year).The direction of succession is oriented to the primary vegetation from the seventh year.