指1979年开始在我国东北、西北、华北三个地区兴建的大型防护林体系Three-North Shelter Forests

• 随着三北防护林工程的实施，陕西省沙区生态环境明显改善。

  With the implementation of the Three-North Shelter Forest Programme, the ecological environment of desert regions in Shaanxi province has significantly improved.

• 三北防护林四期工程建设如期完成。

  The fourth phase of the Three-North Shelter Forest Programme is being completed on schedule.