退化草原围封恢复过程中草场质量动态的研究

Research on the Pasture Quality of Degraded Steppe during Closed Recovering Progress

利用十年研究结果表明，围封后，草场的总产量在第二年即可基本上恢复到与当地的大气降水相互平衡的水平，但其中的草群类型和各种植物生物量的消长变化则是相对缓慢、逐渐进行的。草场质量的动态变化总的趋势是羊草、大针茅、冰草等禾本科优质牧草的比重逐年提高，而菊科、蔷薇科和其他杂类草等饲用价值较低的牧草的比重逐年下降，草场质量有逐年提高的趋势。

en years' research indicates, the dynamic changes of the total biomass was discussed groupsof herbages and pasture quality of degraded steppe during recovering succession after closing. Theresearch results show, after closing, the total pasture yield can basically recover to the level whichbalances with local precipitation at a second year, but the growing and declining changes ofherbage groups and the biomass of different plants are relatively slow and take place gradually.The whole fendency of dynamic changes of pasture quality is that the percentage of high qualityherbage of Poaceae such as Leymus chinensis, Stipa grandis and Agropyron michnoii increase yearby year, but the quantities of low quality grass forages of Compositae, Rosaceae and otherherbages decrease gradually, the pasture quality has a tendency to become better year by year.