桦树在大兴安岭林区,一般当做淘汰的树种。然而在内蒙古西部大青山地区,桦树成为恢复林相的先锋树种,是林分主要组成树种之一。桦树极喜阳光,耐寒性强,一般分布在阴坡和半阴坡的海拔一千五百到二千公尺的高山,和山杨、山柳、云杉等混交生长。其木质优良,用途很广,作为先锋林可大规模育苗造林。桦树种子一般在九 Birch trees in Daxinganling, generally as eliminated species. However, in the Daqingshan area of ​​western Inner Mongolia, birch has become one of the pioneer tree species for restoration of forest facies, and is one of the major tree species in the stand. Birch very hi sunshine, cold tolerance, generally distributed in the shady and semi-shady elevation of 1500 to 2000 meters of mountains, and aspen, willow, spruce and other mixed growth. Its good quality wood, a wide range of uses, as a pioneer Linke large-scale nursery afforestation. Birch seeds are generally nine