极大值原理在确定人工林最优采伐年龄中的应用

人工林可看作一个离散系统,每个采伐分期中各龄级的林分面积定义为系统的状态变量,各龄级的采伐面积定义为控制变量。在控制变量的作用下,人工林从现状态经过N个采伐分期到达一个终端状态,可看作一个控制过程。寻求最优的控制过程的方法有多种,在国内外有关的研究中较为普遍的是多周期的线性规划(或非线性规划)和动态规划。但前者需为每个分期定义控制变量和状态变量,因而计算机计算时占用大量的存贮空间,后者在维数较高时因计算量太大难以求解。极大值原理是最优控制理论中的主要方法之

AN APPLICATION OF MAXIMUM PRINCIPLE IN DITERMINING OPTIMAL CUTTING AGE OF ARTIFICIAL FOREST PLANTATION

Determining the cutting age classes at each cutting time for maximum economic benifit of a planted forest within a planted period can be cosidered as an optimal control problem of an discrete system. According to the timber price, tending cost,reforestation cost, interest rate of bank, as well as the changes of these economic indexes during the whole planning period, each optimal cutting age can be ditermined by appling maximum principle, and the influence of these indexes on the cuttong ages can be also analysed.