不確実性下における林業経営計画 FOREST MANAGEMENT PLANNING UNDER UNCERTAINTY
The forest production greatly relies on nature and variations of the natural conditions related to the production are not small. Then, because of the long production time span, it is necessary to concider the forest management planning as a planning under uncertainty. The purpose of this paper is to present a forest management planning by coordinating the uncertainty and the efficiency of forest production. The theory of stochastic programming is applied. The forest management planning consists of two phases: One is long term and the other is short term. This paper is concerned with the long term planning such as from 60 to 80 years. This planning is how to derive the present forest condition to the objective forest condition and this is one of the most basic requirements in forest management planning. In this paper, the objective forest stand condition is the normal age-class arrangement. A planning method applied here is to minimize the variance of forest yield volume under the condition of keeping its expectation arbitrarily fixed, and the other planning method adopts one of the von Neumann-Morgenstern utility functions. They are formulated as a quadratic programming problem. The methods are applied to a real forest management planning and the unique optimal plan is provided for this case. Our models will be significant in the planning at the divisional forest-office in the national forest.
日本オペレーションズ・リサーチ学会論文誌 20(4), 259-272, 1977