【摘要】 为了探究非生长季降水对草原生态系统生产力和植物物种组成的影响,选取内蒙古羊草草原不同放牧管理历史下的2块样地(中度和过度放牧样地),测定丰雪年份和一般年份的主要植物物种组成、地上部净初级生产力以及降水利用效率,分析内蒙古羊草草原生产力与降水量的相互关系.研究结果表明,非生长季降水的增加显著提高了地上部净初级生产力和降水利用效率,有利于促进冷蒿、冰草和大针茅等深根植物的生长;中度和过度放牧历史样地的生产力和降水利用效率对非生长季节降水量增加的响应基本一致.更多还原

【Abstract】 In order to explore the effect of non-growing season precipitation on the productivity and species composition change in typical steppe,two sampling sites with contrasting grazing history(moderate and heavy grazing plots)in Leymus chinensis steppe in Inner Mongolia were chosen. The main species composition,aboveground net primary productivity(ANNP)and precipitation use efficiency(PUE)during heavy snowfall year and normal year were measured to analyze the relationship between ANPP and precipitation in Leymus chinensis steppe. Main results show that the increase of precipitation during non-growing season significantly improved ANPP and PUE,and promoted the growth of deep-rooted plants including Artemisia frigida,Agropyron cristatum,Stipa grandis,etc. The ANPP and PUE at moderate grazing plot had similar response to the increase of non-growing season precipitation with that at heavy grazing plot.更多还原