三江平原典型草甸小叶章种群地上生物量动态

THE ABOVEGROUND BIOMASS DYNAMICS OF DEYEUXIA ANGUSTIFOLIA POPULATION IN TYPICALELL MEADOW ON SANJIANG PLAIN

本文对东北三江平原典型草甸小叶章种群地上生物量及其组成动态关系的研究结果表明，小叶章种群地上生物量及其组成部分茎、叶、穗生物量季节动态均呈单峰型，在７月末达到极大值，分别为９９６．９５、５７１．４８、４１１．５８、１３．８９ｇ／ｍ２，抛物线拟合效果良好。且相互间存在明显的线性关系，直线拟合效果良好；Ｆ／Ｃ＜１，说明其生产效率较典型草原低，而高于同地区的芦苇种群及陕北黄土高原的禾草群落；Ｆ／Ｃ值和结构比的季节动态表明，其自孕穗期至越冬草形成期之前，相对比较稳定，而后，Ｆ／Ｃ值与叶比迅速下降。这与小叶章种群生长发育节律相一致。

Through the study on aboveground biomass and dynamic relationships among the components of Deyeuxia angustifolia population in typical meadow on Sanjiang Plain, the results showed that the seasonal dynamics of the aboveground biomass of population and that of its componentsstem, leaf and ear are all appeared the shape of single peak type, and reached their maximum values in July, which respectively were 996.95,571.48,441.58,13.89g/m 2. the effect of linear regression was very good; they were appeared obvious linear relationships, the effect of parabolic regression was also good. F/C<1 implied that its production efficiency was lower than that in typical grassland, but higher than that of Phragmites communis population in the same area and that of grass communty on Yellow Plateau in the north of Shannxi; the seasonal dynamics of F/C values and component ratio were relatively stable from the phase of before earing to the formation of hibernating bud, afterward F/C and leaf ratio abruptly fell down, this was accordance with the growth rhythm of Deyeuxia angustifolia population.