农牧交错区土地利用动态与生态效应变化--以榆阳区为例

以榆阳区1988-2003年土地数据为依据，在分析研究区土地利用的数量和结构变化特点的基础上，运用国内外学者在生态价值估算的方法与模式，结合该区的具体情况对估算方法进行修正，然后对研究区研究时段内各年度的生态系统服务功能经济价值进行了估算，并以1988年为基准测算了土地利用类型的数量和结构变化所引起的生态系统服务功能经济价值变化情况，分析了其变化的时段特点及变化原因，定量地揭示了在生态脆弱区环境与经济发展的关系。研究表明：1988-2003年，榆阳区土地利用变化所产生的环境响应总体米说是积极的，生态系统服务功能经济价值年度总量在波动中提高；营造防护林、退耕还林及农用地内部结构调整政策的实施实现了经济和环境双赢的预期效果。

Relation Between LUCC and Ecological Effect Change in Pasturing-farming Ecotone: A case study on Yuyang District

Based on the land use/cover change(LUCC)survey data,the features of LUCC in Yuyang District located in the pasturing-farming ecotone between the Mu Us Desert and the Loess Plateau during 1988-2003 are analyzed.With the parameters according to the local conditions of Yuyang District,the method and mode about ecological value estimation are used to estimate the economic worth of ecosystem service function of Yuyang District during 1988-2003.The paper analyzes the feature and reason of the changes of the economic worth of the ecosystem service function in different periods and explains the relation between the environment and economic development in ecological fragile district.Studies show that the environment respond to LUCC was positive and the economic worth of the ecosystem service function improved in general during 1988-2003 in Yuyang District.The economic worth of ecosystem service function of Yuyang District in 1988 is 2 950.13 million Yuan RMB and the economic worth of ecosystem service function of Yuyang District in 2003 is 3 178.02 million Yuan.The latter is 227.89 million Yuan more than the forth.Among them,the economic worth of ecosystem service function of the forest land has increased by 228.77 million Yuan,accounting for 81.1% of the total value-added,and that of the garden land has increased by 53.32 million Yuan,accounting for 18.9% of total increase.The economic worth of ecosystem service function of the cultivated land,grassland,water land and wasteland have reduced 11.82 million Yuan,33.46 million Yuan,4.51 million Yuan and 4.41 million Yuan,accounting for 21.8%,61.7%,8.3% and 8.1% of the total reduction respectively.The implementation of policy of building the shelter forest,returning farmland to woodland and adjusting inner structure of agriculture,has made a great progress both in local economy and environment.