关键词: 农牧交错区, 人类活动, 开垦草原

Abstract: The climate in the agricultural and pasturing interlaced zone of Gansu, Ningxia, Inner Mongolia and Shaanxi belongs to semi arid type in temperate or warm temperate zone. The natural vegetation in this area includes forest pasture and typical steppe. This was a place where agriculture and animal husbandry took their turns in historical period despite of the generally suitability for pasturing. Because of the population increasing with time the cultivated area extended gradually and the pasturing area dwindled accordingly. Consequently, the local fragile ecology-economy-society integrated system was disturbed. Land desertification and new sand sources occurred. Sandstorms took place frequently in the down wind regions. For restraining land desertification extending and re establishing the ecological barrier the industry pattern dominated by animal husbandry must be constructed. The areas inadvisable to cultivation should be returned to forestry and grassland.

Key words: agricultural and pasturing interlaced zone, human activity, grassland reclamation