现代,木材主要用作建筑材料。在这种情况下,必须把低劣木材与采伐和加工中得到的废材作为化学加工原料加以利用。采伐木材时,约有25%的伐根、树皮、枝叶留于伐区。在伐倒的木材中,低劣的薪材也占很大的比例,例如,苏联在1957年采伐的总材积中,有36.5%是薪材,阔叶过熟林中,薪材的百分比就更高。转运价值低的薪材是 Modern, wood is mainly used as building materials. In this case, poor wood and waste materials obtained from logging and processing must be used as raw materials for chemical processing. When harvesting timber, about 25% of the stump, bark, leaves remain in the cutting area. In the case of felled wood, poor fuelwood also accounts for a large proportion. For example, of the total volume of logging in the Soviet Union in 1957, 36.5% were fuelwood. In the broad-leaved and over-mature forest, the percentage of fuelwood was even greater high. The low-value-for-money fuelwood is