Abstract: The experiment was conducted in Inner Mongolia steppe located at 43°-26'-44°8'N,116°04'-117°05'E,The vegetation was dominated by Artemisia frgada and short-grasses and the soil type issandy chestnut.The average precipitation was about 350mm which was main concerntration in summr andthe average temperature was-0.4℃.The grazing treatments included 5.stocking rates(1.33,2.67,4.00,5.33 and 6.67 sheep/hm²)with three 1hm² rotational paddocks at the beginning of 1990.Through 8 years studying,the results showed that the lighter stocking rate(1.33-2.67 sheep/hm²)can increase the proportion of grasses,such as Leymus chinensis,Stipa krylovii and Agropyron cristatum,the plant diversities index and evenness and improve the rangeland condition; but the Artemisia frigidarangeland will be continue degradated to Potentilla acaulis rangeland which the proportion of grass herbageand plant diversity index were decreased.The Potentilla acaulis may be resistent to rangeland degradationang desertation furtherly.

Key words: Inner Mongolia, Artemisia frigida rangeland, Stocking rates, Community succession

摘要： 研究不同放牧率的围栏轮牧。结果表明,在冷蒿小禾草退化草原,1.33-2.67羊/hm²的放牧率将使草原发生逆行范管,导致禾草的比例增大,植物多样性指数和均匀度指数均有所提高,从而达到利用式改良的目的。相反,若继续进行重牧或过牧,绵羊喜食的植物种类将进一步减少,植物多样性指数也有所降低。最终将趋同于星毛委陵菜退化草原群落,而星毛委陵菜则是防止草场沙化荒漠化的草种之一。

关键词: 放牧率, 内蒙古, 冷蒿草原, 群落演替