【摘要】 在松嫩草原野外条件下,采用模拟升温和氮沉降的控制实验探讨了羊草(Leymuschinensis)种群数量特征的响应机制.结果表明:施氮可以显著促进羊草生长,增加羊草种群的高度和密度,加快羊草种群的分蘖速度,进而增加羊草种群在整个群落中的重要值,从而提高羊草的竞争力.增温处理对羊草各项数量特征的影响不显著.增温加施氮处理可使羊草的重要值显著增加,具有协同作用.在整个观测期中,从5月21日到6月17日,增温、施氮处理后的羊草物候期分数均高于对照;从6月24日到8月10日,增温和施氮处理后的羊草物候期分数均低于对照.这说明处理后羊草的春季物候期提前,种子的脱落期延后,落叶推迟,生长期延长.而增温加施氮的交互处理对羊草物候期则无明显影响.更多还原

【Abstract】 This thesis discussed that responses of Leymus chinensis quantity characteristic to simulated waring and nitrogen applying in Songnen Grassland.The results showed that nitrogen fertilization can significantly promoted L.chinensis growth,increased the height and density of L.chinensis and accelerated the speed of L.chinensis tiller,thus increasing the important value of L.chinensis population in the entire community,thereby enhancing the L.chinensis competitive ability.It did not were significantly that warmingto affect the various quantitative characteristics of L.chinensis.The warming plus nitrogen application increased significantly the important values of L.chinensis,having a synergistic effect.Throughout the observation period,from May 21 to June 17,the L.chinensis phenophase scores of the warming,N treatment were higher than that of the control;from June 24 to August 10,it were lower than the control.This showed that L.chinensis spring phenophase advance,seed shedding period delayed defoliation postponed and the longer growing season.Warming plus nitrogen fertilization had no obvious impact.更多还原