大兴安岭是我国重要木材生产基地之一.自1964年开发以来,森林覆被率不断发生变化.本区开发前的森林覆被率为71%,主要树种为兴安落叶松与白桦,占有林地蓄积的57%与11.7%,但据1976年清查资料,森林覆被率为56.9%. 一个地区的森林覆被率是衡量一个林区森林资源多少的标志,森林资源多少也是生态平衡的关键所在.森林是再生的能源,森林的多少是衡量林业现代化的重要标志. 人们从实践中逐步提高了对森林多种效益的认识,不重视发展森林必将受到大自然 Daxinganling is one of the important timber production bases in China, which has been changing continuously since it was developed in 1964. Before the project was developed, the forest cover rate was 71%, with the main species being larch and birch, and the accumulated forest land 57% and 11.7% respectively, but the forest cover rate was 56.9% according to the inventory data in 1976. The forest cover rate in one area is the measure of the forest resources in a forest area, and the forest resources are also the key to ecological balance. Is a renewable energy, the number of forests is an important indicator of the modernization of forestry.People gradually from practice to improve the understanding of the variety of benefits of the forest, do not attach importance to the development of the forest will be affected by nature