On dealing with strategic and tactical decision levels in forestry planning under uncertainty

Abstract

A new scheme for dealing with the uncertainty in the scenario trees is considered in the presence of strategic and tactical stochastic parameters for a dynamic mixed 0-1 optimization model in a forest harvesting network along a time horizon under uncertainty. The strategic level of the model presented in this work is included by a several years time horizon, where the uncertainty lies in the timber production. It is represented in a multistage stochastic scenario tree, such that each stage comprises one or several years. Each node in the strategic tree has associated a multi-period scenario graph, where each period in the stages is related to a summer /winter season. The nodes in the graph represent the tactical uncertainty, whose stochastic parameters are the timber price and demand. The strategic decisions aim to the optimal design of the logistic timber harvesting and distribution network at each first period in the stages. The tactical decisions aim to timber harvesting, stocking and distribution from the stands until the markets at the periods in the stages. The model has been validated by using data from a real-life problem.