“三北”防护林工程建设使三北地区生态环境得到明显改善，并产生了显著的社会和经济效益。然而，市场经济的建立又使工程建设面临多重困难和考验。如何使“三北”防护林工程建设能够持续、稳定地发展，实现两个根本性转变，采取增加投入、分类经营、加大科技含量、引进并建立新的经营机制以及各种资源的合理优化配置等措施，就成为今后工程建设的关键 The construction of the “Three Norths” shelterbelt project has obviously improved the ecological environment in the Three North Regions and produced significant social and economic benefits. However, the establishment of a market economy in turn causes construction projects to face multiple difficulties and tests. How to make the construction of “Three Norths” shelterbelt project sustainable and steady, realize two fundamental changes, take increasing investment, operating in different categories, increasing scientific and technological content, introducing and establishing new management mechanism and rational allocation of various resources And other measures, it has become the key to the construction of the future