目前,大兴安岭地区培育的一年生落叶松苗木,多数达不到出圃造林标准,需留床或换床再培育一年。就落叶松造林的苗木质量而言,换床苗的质量高于留床的质量。留床的二年生落叶松苗木苗茎与主根细长,侧根很少,对于不良的生境其抵抗力弱,造林成活率低,成林慢。而换床的二年生苗木,由于增加了营养面积、改善了苗木的通风和光照条件,苗茎粗壮,主根粗 At present, most of the annual larch seedlings nurtured in the Greater Xing’an Mountains can not reach the standard for afforestation. They need to stay or change beds for another year. In terms of the quality of larch afforestation nursery, the quality of bed nursery stock better than the quality of the bed. Two-year-old larch seedling seedling seedling stems and stems elongated, with few lateral roots, poor resistance to poor habitat, afforestation survival rate is low, slow forest. The bed of perennial seedlings, due to an increase of nutrient area, improve seedling ventilation and lighting conditions, seedling stem thick, the main root thick