退耕还林项目对陕北地区自然与社会的影响

 【方法】应用试验监测与社会调查相结合的方法，研究和报告中国退耕还林项目对区域生态景观系统快速变化的影响。【目的】为生态修复政策对自然和社会的影响提供可借鉴的研究案例。【结果】中国陕北地区实施退耕还林政策以来，地表植被覆盖度由1998年的34.6%增至2005年的49.2%；但是干旱半干旱生态脆弱区大规模的人工造林可诱发严重的水资源短缺、导致人工林地植被覆盖度减小、以及对植物种类多样性的负面影响，相对而言，封山禁牧对生态脆弱区的植被修复效果最好；生态政策与项目的有效实施离不开公众的大力支持，不幸的是88.8%的居民希望获得政府对农业生产项目的支持而不是开展植树种草。【结论】调查结果表明，退耕还林项目恢复的植被在项目结束后有可能被重新开垦为农田，该项目获得的环境成果面临再次毁灭的风险。因此，把发展经济、改善教育与环境修复有机地结合起来，是环境修复项目成功的重要保证。

Impact of Grain for Green Project to Nature and Society in North Shaanxi of China

There is a global need to restore the functional integrity of nature; a proposal advanced because forests are so large in their influences on global biophysics. Here we examine the results of a rapid landscape-scale shift in ground cover/use from 1999 to 2004, China’s “Grain for Green Project,” as a practical example of a large scale attempt to restore a vulnerable environment. The project’s results thus far indicate that while natural coverage increased from 34.6%% to 47.2% in the northern part of Shaanxi Province. Although only 34.08% farmers declare they will cultivate grass-forest-land again when compensation for grain not produced is stopped, we believe that the restored vegetation may be completely reconverted back to cultivation at the program’s end and thus compromise the sustainability of the program’s environmental achievements.