一、吕梁森林经营局残次林分改造的概况山西省吕梁森林经营局地处吕梁山脉南端,总面积31.39万 ha,国有经营面积20.13万 ha,其中有林地面积7.35万 ha。在有林地面积中,约有3.67万 ha 为阔叶低质次生林分,约占全局有林地总面积的50%左右。这些低质次生林分,主要以栎类树种为主(占蓄积量的50%以上),树形多呈灌木状,主干低、分叉多,弯曲度大。单位面积蓄积量每亩平均3m~3左右,规 First, Luliang Forest Management Bureau of the second transformation of the profile of Luliang Forest Management Bureau in Shanxi Province is located in the southern tip of the Lvliang Mountains, with a total area of ​​313,900 ha, state-owned operating area of ​​201,300 ha, of which forest area of ​​73,500 ha. In the forest area, about 36700 ha for the broad-leaved low-quality secondary forest, accounting for about 50% of the total forest land. These low-quality secondary forests, mainly oak tree species (accounting for more than 50% of the volume), mostly shrub-like tree, the trunk is low, more bifurcation, large curvature. Volume per unit area per acre an average of about 3m ~ 3, regulations