现实异龄林分最优择伐序列的探讨

该文用末端自由的最优控制模型作为现实异龄林分的生长经营模型，用梯度法求解，对长白山林区云冷杉为主的异龄林求解结果比较令人满意。从求解结果中得出，此现实异龄林经２～３次择伐后的各次择伐强度变化较平稳，林分径阶结构逐渐趋于一种稳定状态；择伐周期以１０～１５ａ较适宜；还得出对应于各种择伐方案的择伐强度、保留蓄积、出材量等初步结论。

Optimum Sequence of Selective Cutting for Actural Uneven-aged Stand

In this paper,end-free optimum·control model is used as the growth manage-ment model of actual uneven-aged stand, then gradient programming technique is used forsolving the problem. The solution of the uneven-aged stand in Changbaishan forest regionwhich is dominated by Spruce and Fir is satisfying. From the result,some conclusions can bedrawn. After two or three times of selective cutting,the intensity of it changes smoothly andstand diameter-class structure tends to be in a steady state gradually,It is proper that cuttingcycle is about fifteen years. Other conclusions,such as selection rate,residual stand volume,and harvest volume for given selection scheme are also drawn roughly.