六盘山林区直到目前还是荒山多于林地;灌林多于乔林。虽然现有林面积49万余亩(其中次生林24万余亩,乔灌混交林8万余亩,灌木林16万余亩),而宜林地荒山荒地为有林地面积的1.7倍左右。要想在几年内使荒山草地变成绿林,使低产林变为高产林,提高林分生产力,就必须发展种 Liupanshan forest until now or barren hills more than woodland; Although the existing forest area of ​​more than 49 acres (of which more than 240,000 acres of secondary forest, mixed forest of more than 80,000 acres of shrubs, shrubs more than 16 acres), and the forest wasteland of Yulin to forest area of ​​about 1.7 times. If we want to turn the barren hills and grasses into green forests within a few years and make the low-yield forests become high-yield forests and increase the productivity of the stands, we must develop species