内蒙赤峰大局子林场自1954年起就开始了次生林改造工作,10年来共完成改造面积9,600亩。该场采取了三种改造方式:疏林改密林,灌林改乔林及成熟林皆伐迹地更新。改造时引进树种中,云杉占40%,落叶松占30%,油松占20%,樟子松占10%。据几年来观察记载,保存率高,幼树生长良好:云杉播种造林7年后幼树保存率86%,平均高1.4米,平均胸径1.0厘米;落叶松栽植造林4年后幼树保存率78%(皆伐 The overall situation in Inner Mongolia Chifeng Forest Farm since 1954 began the second transformation of the forest, 10 years, completed a total renovation area of ​​9,600 acres. The field has taken three transformations: changing forests to forests, filling forest to forest and mature forests are cutting to update. Transformation of the introduction of species, spruce accounts for 40%, larch 30%, Pinus tabulaeformis 20%, Pinus sylvestris 10%. According to years of observation and records, the preservation rate is high, the saplings grow well: after 7 years of spruce plantation sapling survival rate of 86%, an average height of 1.4 meters, an average diameter of 1.0 cm; 4 years after larch plantation sapling save rate 78% (clear cutting