祁连山水源林调整林分结构的数学模拟

Simulation on Stand Structure of Adjustment of Water Conservation Forest in Qilian Mountains

通过实际调查和分析看出，祁连山林区林分直径结构存在着不合理的分布状态，林木分化比较严重，小径木株数所占比例较大。因此，调整林分直径结构，应将小径木及劣质木做为抚育采伐对象，杜绝以往抚育采伐中的“拔大毛”现象，并且通过Ｗｅｉｂｕｌｌ分布拟合，反映出弱度采伐中，只要尊重现实分布律，制定科学的抚育措施，就能使林分结构向合理方向发展。

According to investigation and analysis,there ezist unreasona-ble distribution of stand dianleter structure,serious trees differentiationand bigger percentage of small diameter grade in forest region of QilianMountains. Therefore the trees of small diameter grade and low quantily isthe target of tending felling in order to forbid cutting favored tiees only asusual. By fitting Weibull distribution,it shows that forest dian1eter structurecan approach completion by light tending felling, as long as to respect lawof realistic dialneter distribution and make scientific method.