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一、天然林机械择伐课题的提出在目前的国营林业采育场中由于常年不断的采伐,天然林不断的减少,而人工林逐渐增多,有些场已经面临天然资源接近枯竭,而新培育的人工林尚接续不上的资源危机之中。在接近枯竭的天然林资源中,由于砍伐已深入腹地和经营区边缘,地形日益复杂,林木的林相不齐,复层林多,单位面积蓄积量低,且侧重生态效益的防护林增多,武夷山市林委所属国营林场这类林地占经营区总面积的26%。这类林地大多生长着一定数量的马尾松过熟林,由于过度采脂或自然枯损。不采伐也会死亡,造成资源损失;有些林地林相很差,大量生
First, the proposal of natural forest mechanized sequestration issues In the current state-owned forestry mining farms due to perennial harvesting, natural forests continue to decline, while the plantation gradually increased, and some fields have been facing the depletion of natural resources, and newly cultivated Plantation is still unsustainable resource crisis. Near the depleted natural forest resources, deforestation has become more and more complex due to the deepening of the hinterland and the edge of the business area. The forests are not homogeneous, and there are many stratified forests. The reserve per unit area is low, and the number of shelterbelt with ecological benefits increases. The forest owned by the state-owned forest farms belongs to 26% of the total area of the operating area. Most of this type of woodland grows with a certain amount of over-mature Pinus massoniana, due to over-grease or natural wilt. Do not cut will die, resulting in loss of resources; some woodland forest is poor, a large number of students