The Study of Thinning and Its Optimum Control for Larch Plantation

Based on the stand growth models,a discrete deterministic dynamic program-ming model was established which took the management index as state variables, the mean diameter of final cutting as a goal and the total volume as the objective function at the time when the goal is reached.A computer simulation system was produced. With this system,the optimum thinning time,thinning intensity and final cutting age could be decided for larch plantation with different goals.The result shows that the number of reserved trees,number of times of thinning and total volume yield calculated by this method are better than those by the common one.It not only forecasts growth of stand for larch plantation but also provides basis for making managerial plans.