小陇山林区29年生油松人工林抚育效果评价

Evaluation on Thinning Effect in Young and Middle-Aged Pinus tabulaeformis Forest in Xiaolongshan Forest Region

运用状态评价和功能评价相结合的方法对油松(Pinus tabulaeformis)人工林中幼林龄抚育间伐前后林分状态变化进行了分析。结果表明:抚育后林木的分布格局由均匀分布靠近随机分布。平均混交度略有上升,幅度不大。但优势树种油松的混交度呈明显上升趋势。油松人工林直径大小比数变化不大,保持了油松在群落中的优势地位。开敞度则由于抚育间伐后林木间距的增大而得以提高,达到了优化目的,林分的胸径平均生长率提高了47.8%,蓄积生长率提高了51.7%,充分说明适宜的抚育间伐可提高林分各树种生长率,从而使林分逐步达到健康稳定的林分结构。抚育间伐样地天然更新增加了11.1%。对照样地天然更新减少了9.8%。

The change of structure in a young Pinus tabulaeformis forest before and after thinning was analyzed by combining state evaluation and function evaluation. Results showed that the distribution pattern of the forest changed from uniform distribution to random distribution after thinning. The average mingling degree increased slightly. However, the mingling de- gree of dominant tree species P. tabulaeformis showed a clear ascendant trend. The neighborhood comparison of diameter of P. tabulaeformis forest changed little, maintaining the dominant position of P. tabulaeformis in the community. The open degree improved because of the increase of tree spacing after thinning, which achieved the optimization purposes. The average growth rate of diameter at breast height increased by 47.8% , and the volume growth rate increased by 51.7%. Therefore, proper thinning can improve the stand growth rate, which results in a healthy and stable stand structure. The natural regeneration in the samole olot after thinnin increased hv 11.1% while that decreased by 9. 8% in the control plot.