摘要
【目的】退耕还林还草工程的生态效益可以由农田生态系统转变为林草生态系统服务价值的增加量来体现。对退耕还林还草工程的生态系统服务价值进行估算,可以为验证退耕还林还草效果、完善退耕还林还草政策提供科学依据。【方法】根据黄土丘陵沟壑区退耕还林还草工程实施前后生态系统特征的变化和生态系统服务的内涵,选取土壤保持、涵养水源、维持营养物质循环、固碳释氧、净化空气、保护生物多样性等指标,运用市场价值法、费用替代法、影子工程法、机会成本法等研究了安塞县退耕还林还草工程生态系统服务功能及价值的时空变化,并对退耕后生态系统中各植被类型的服务价值进行了评估。【结果】实施退耕还林还草工程以来,安塞县退耕还林还草工程的生态系统总服务价值,从退耕前(1998年)的188.37亿元增加到退耕后(2005年)的241.03亿元,增幅达27.95%;在生态系统各项服务功能价值的贡献中,涵养水源价值量最高(77.08%),接近于总价值的3/4,其次是土壤保持价值(11.43%)、维持营养物质循环价值(6.83%)、固碳释氧价值(3.94%)及保护生物多样性价值(0.54%),净化空气价值(0.18%)最低;实施退耕还林还草工程后,各植被类型的总服务价值表现为灌木林>草地>乔木林>经济林;从各植被类型单位面积的系统服务价值量来看,系统服务功能大小依次表现为乔木林>灌木林>草地>经济林>农田。【结论】实例分析表明,退耕还林还草工程的实施,在保护环境、治理水土流失等方面具有显著作用。
[Objective] The ecological benefits of Converting Farmland into Forest and Grassland Project could be measured by the increase of ecosystem service value after the conversion. The assessment of the Project＇s ecosystem service value can validate the Project＇s impact and provide scientific foundation of policy. [Method] According to the changes of ecosystem characteristics brought by Converting Farmland into Forest and Grassland Project and the definition of ecosystem service value, six indexes, including soil conservation,water storage, nutrition circulation, assimilation of CO2 and O2 release, air purification and biodiversity protection,were adopted to measure the spatiotemporal changes of ecosystem service function and value in Ansai county combined with a series of scientific methods,also the service value of different vegetation type were evaluated. [Result] The results indicated, thanks to Converting Farmland into Forest and Grassland Project,the total ecosystem service value of Ansai county increased by 27.95% ,from 18. 837 billion yuan in 1998 to 24. 103 billion yuan in 2005;the service value of water storage was the highest,accounting for nearly 75% of total ecosystem service value,then followed by the soil conservation（11. 43%） ,nutrition circulation （6. 83%）, assimilation of CO2 and O2 release （3. 94%）, biodiversity protection （0.54%） ,the service value of air purification was the lowest,only 0.18% of total ecosystem value;of all the vegetation types, shrub forest had the highest service value, then the grassland, arbor forest and economic forest;as to the per unit area service value, the sequence were arbor forest, shrub forest ,grassland, economic forest,cropland. [Conclusion] As a conclusion, Converting Farmland into Forest and Grassland Project has great significance in environment protection,mainly in controlling water and soil erosion.
出处
《西北农林科技大学学报（自然科学版）》
CSCD
北大核心
2008年第6期131-140,共10页
Journal of Northwest A&F University(Natural Science Edition)
基金
国家重大基础预研项目(2005CCA05300)
西北农林科技大学青年骨干支持计划项目
关键词
退耕还林还草
生态系统服务价值
时空分析
植被类型
黄土丘陵沟壑区
converting farmland into forest and grassland project
ecosystem service value
spatiotemporal analysis
vegetation type
Loess Hilly and Gully Areas
