论文部分内容阅读
当今世界上有八大生态工程,除了美国罗斯福工程、苏联斯大林改造大自然计划、北非绿色坝建设三大项生态工程外,其余的五大生态工程都在我国。一、中国“三北”防护林体系.1978年开始建设,范围包括东北西部、华北北部、西北东部的551个县旗市,面积为406.9万平方公里,占国土总面积的42·4％。截至1988年,人工造林900多万公顷
There are eight major ecological projects in the world today. Apart from the three projects of the Roosevelt project in the United States, the Stalinist transformation of the nature in the Soviet Union, and the green dam construction in North Africa, the remaining five major ecological projects are in our country. First, China’s “Three Norths” shelterbelt system started construction in 1978 and covered 551 counties in the western part of Northeast China, northern part of North China and eastern part of Northwest China, covering an area of 4,609,000 km2, accounting for 42.4% of the total land area. As of 1988, more than 9 million hectares were afforestated