“三北”防护林地区位于我国北部,包括西北、华北大部和东北西部,总面积389.2万平方公里,约占全国陆地面积的40.5％。全区仅有森林1470万公顷,森林(包括灌木林)覆盖率只有3.8％。由于森林植被缺乏加剧了干旱、风沙、水土流失等自然灾害,生态循环恶化,经济发展落后。我国政府对“三北”地区国民经济的发展十分重视。70年代末,国家决定建设“三北”防护林,提高森林覆盖率和畜牧业比重。“三北”防护林体系第一期工程投资近11亿元。各地上报造林面积达700万公顷。当前,国家经济管理部门迫切需要了解这些年来“三北”防护林工程投资的实际经济效益和生态效益,以及经济政策和技术措施的效果,以便为制定和修改“三北”防护林工程建设规划提供可靠依据。 The “Three Norths” shelterbelt region is located in the northern part of our country, including the northwest, most of North China and the western part of Northeast China with a total area of ​​3,892,000 square kilometers, accounting for 40.5% of China’s total land area. The region has only 14.7 million hectares of forests, forests (including shrubs) coverage of only 3.8%. Due to the lack of forest vegetation aggravating the natural disasters such as drought, sandstorm and soil erosion, the ecological cycle has deteriorated and the economic development has lagged behind. My government attaches great importance to the development of the national economy in the “Three Norths” region. In the late 1970s, the state decided to build a “three northern” shelterbelt to increase the proportion of forest coverage and livestock husbandry. The “Three Norths” shelterbelt system project invested nearly 1.1 billion yuan. The reported afforestation area reached 7 million hectares. At present, the state economic administration urgently needs to understand the actual economic and ecological benefits of the “Three Norths” shelterbelt project investment over the years and the effects of economic policies and technological measures in order to provide a reliable basis for formulating and revising the “Three North” shelterbelt construction plan in accordance with.