凉北林区位于四川省的大凉山上。海拔较高,又冷又湿,在植物生长季节里,气温低,有效积温少,湿度大,光照少。形成以冷杉为主的大面积天然纯林。采伐后冷湿条件仍然突出。经过多年的树种选择试验,冷杉还是难以代替的更新造林树种。由于生产的需要,一九六三年开始进行了冷杉壮苗培 Liang Beilin District is located in Sichuan Province, Liangshan. High altitude, cold and wet, in the plant growth season, the temperature is low, the effective accumulated temperature less, humidity, light less. The formation of fir-based large area of ​​natural pure forest. Cold and wet conditions after harvesting is still prominent. After many years of tree species selection test, fir is still difficult to replace the reforestation tree species. Due to the needs of production, strong fir seedlings were cultivated in 1963