The decrease in area of meadow grassland and temperate grassland with high production vs . increase in area of desert grassland with low production indicated a dramatic degradation of the grassland in north china and the overwhelming impacts of human activities superimposed on the natural grassland ecosystem 草甸草原面积亦呈逐年减少的趋势,从1987年的1103km ~ 2减少到2000年375km ~ 2 ,面积减少了65 . 9 。优质高产草原类型面积的减少,以及荒漠类低产劣质草原面积的增加,预示我国北方优良天然草场资源正在急剧退化。