土地利用变化与生态服务功能冲突——以安塞县为例

安塞县位于黄土丘陵沟壑区,经济落后,农业生产水平较低.从土地利用和生态服务功能变化与冲突的角度,分析安塞县农业、环境与生态保护的变化过程与相互作用,指出安塞土地利用变化突出表现为坡地耕垦所引发的土地利用结构的改变;生态服务功能的冲突则主要表现为食物生产与水土保持之间的矛盾.通过资源的有效利用,在实现食物安全的同时,水土流失得到有效控制是完全可能的.

Study on Land Use Change and the Corresponding Contradictions of Ecological Services——A Case Study in Ansai County, the Loess Plateau

Slope cultivation,serious soil erosion,population pressure,food insecurity and low agricultural productivity are the main issues in rural development in Ansai County in the Loess Plateau.In order to meet the increasing food demand due to population growth,slope cultivation was widely practiced in the past decades,thus the serious soil erosion and reduction of the service capability of ecosystems were resulted in.This paper analyzes land use change and its causes as well as the corresponding contradictions among the ecosystem services in Ansai County,and discusses the main potential limitations and the policy measures to alleviate these problems.The results show that the contradictions between food production and soil conservation are not as strong as expected.The current low agricultural productivity due to the very limited external inputs and poor soil management can be significantly improved by the effective utilization of natural resources and the enough inputs,thus the current slope cultivation and the corresponding serious soil loss can be greatly reduced.Since the lack of off-farming opportunities for employment and income generation,the impacts of implementing the project dominated by environment regeneration and the so-called project of "returning slope land for farming to forestry and animal husbandry" on employment of rural labors must be considered.In the long term,terracing,crop growing in rotations with alfalfa,and intensification of arable lands by increasing inputs should be enhanced so as to improve soil conservation and increase food production except implementing the project of returning marginal farmland to forestry or animal husbandry.As the project of returning land for farming to forestry and animal husbandry can reduce the employment opportunities of rural labors,livestock development,such as indoor feeding of pigs and sheep,should be addressed by growing more corn and alfalfa.In order to promote these changes,the appropriate policy measures aimed at improving the land tenure system must be developed and implemented.