论文部分内容阅读
在内蒙古西部山地,白桦次生林面积约有6.5万多公顷,占该地区次生林面积的46％。主要分布在大青山、蛮汉山、灰腾梁、乌拉山等山地的阴坡、半阴坡。白桦次生林由于多代萌生,林分疏密度不均、干形不良,生产力很低,一般每公顷蓄积量为35～90立方米,最好的也不过90多立方米,急需采伐利用和更新改造。七十年代以来,生产单位对白桦次生林主要采用小面积皆伐,利用萌芽进行更新
In western Inner Mongolia, birch secondary forest area of about more than 65,000 hectares, accounting for 46% of the area of secondary forest area. Mainly distributed in Daqingshan, quite Han Shan, Gray Leung, Wulashan and other mountain shady, semi-shady. The birch secondary forest is sprouted from generation to generation, with uneven density, poor dryness and low productivity. Generally, the volume per hectare is 35-90 cubic meters and the best is more than 90 cubic meters. . Since the seventies, the production unit of secondary birch secondary forest are mainly used for small-scale clearance, the use of sprout to be updated