华北落叶松育苗在高寒地区是2年出圃,留床期间,苗木生长旺盛,主根发达,侧须根很少,茎高而不粗壮,造林后成活率较低。为解决这一问题,我们于1980年进行了断根育苗、造林试验,取得了较好的效果,后经几年连续试验和生产实践,效果均很好。一、试验地概况试验地设在我场苗圃地,海拔高1,450米,年降雨量350-400毫米,年平均气温2.1℃,无霜期90天,气候寒冷、干旱,常年多风。供试苗木为1979年落叶松播种苗,当年苗平均高5厘米,平均地径0.2厘米,每平方米有苗500株。二、试验材料和方法在圃地选择生长正常、有代表性的苗床6 Larix principis-rupprechtii nursery can be nursery for 2 years in the alpine region. During the stay of the bed, the nursery stock grows vigorously with developed main roots, few lateral follicles, high stalks but not thick stalks and low survival rate after afforestation. In order to solve this problem, we carried out the root-cutting and seedling afforestation experiments in 1980 and achieved good results. After several years of continuous testing and production practice, the results were very good. First, the experimental site Overview Experimental site located in my field nursery, 1,450 meters above sea level, the annual rainfall of 350-400 mm, the annual average temperature of 2.1 ℃, frost-free period of 90 days, the climate is cold, dry, perennial windy. Seedlings for the test of larch sowing in 1979, when the average seedling height of 5 cm, an average diameter of 0.2 cm, 500 per square meter seedlings. Second, the test materials and methods in the nursery to select a normal growth, a representative of the seedbed 6