中国生态脆弱带人地关系行为机制模型及应用

以农牧交错带为研究对象,通过建立人地关系行为机制模型,探讨外部社会经济因素影响土地退化的机制,并重点就当前正在实施的退耕还林还草政策所带来的生态经济效果进行分析。模型拟合结果显示,利用玉米及农作物秸秆作为饲料,扩大舍饲动物饲养,或者扩大种植葵花或油料作物等商品作物以替代自给性作物糜子,将可以在不加剧水土流失的前提下增加农户收入。模型结果还显示,非农就业机会增加时,农户会减少坡地垦殖。这表明推进农村工业化和城镇化发展,增加农民非农就业机会,鼓励农民进城的政策对于黄土高原的水土保持也是有促进作用的。

An Application of Bio-economic Household Model to Analysis on Man-Land Relationship Behavior in Ecologically Fragile Land of China

Land degradation is one of the severe environmental problems in China. In order to combat land degradation, a soil conservation program has been introduced since 2000 to reduce soil erosion by converting slope farmland into forest and pasture. This paper represents the first systematic attempt to investigate the impact of the soil conservation program on land degradation in the Loess Plateau. The results indicate that the soil conservation program to convert slope land into forest or pasture is an effective way to combat soil erosion. However, a subsidy that is higher than profit from slope land use activity before conversion is needed to encourage farmers to join the conservation program. Relevant policies to encourage and assist farmers to raise livestock in folds with crops produced from fields as well as fodder and forage grass from the converted slope land might contribute to combat soil erosion. Increase in off-farm job opportunities may encourage farmers' households to reduce farming practices on slope land. This implies that policies to encourage ruralurbanization might contribute to combat soil erosion.