内蒙古草地面积的变化及其成因分析——以锡林郭勒盟多伦县为例

Variation of grassland area and its cause in Inner Mongolia ——A case study on Duolun County of Xilin Gol League

利用地面调查与遥感技术相结合的方法,研究了草地面积的演变和成因。结果表明,1971-2007年,多伦县草地面积呈波动性变化,20世纪80年代面积为227 640.93hm2;90年代面积最小,为166 929.43hm2;2000年以后,随着退耕还林还草工程的实施,草地面积与20世纪80年代末持平。影响草地面积变化的主要因素是气候暖干化背景驱动下的人为干预和扰动。20世纪80年代,人为的过度放牧,草地沙化和退化严重;在温暖湿润的20世纪90年代,大量草地被开垦成农田,湖沼和湿地面积扩大侵蚀草地,使草地面积减少;2000年以后尽管降水减少,但人为治理使草地得到逐步恢复。

Variation of grassland area in the Duolun County of Xilin Gol League was presented by combining field survey and remote sensing technology and its causes were discussed in this study. The results of this study showed that grassland area in Duolun County was fluetuant from 1971 to 2007, indicating that the grassland area decreased from 227 640.93 ha in 1980 s to 166 929.43 ha in 1990 s, and restored to grassland area of the 1980 s in 2000 due to conversion of cropland to forest and grassland. Under the cli mate warming and drying, human disturbance was key factor affecting the grassland area. Plenty of grasslands were reclaimed into croplands and were substituted by the lakes and marshes in 1990 s when the climate was warm and humid, resulting in the decrease of grassland areas. In 1980 s, grassland degenerated and deserted because of overgrazing. Although the rainfall decreased, the grassland had been gradually restored because of better management from 2000 to 2007.