Forest management optimization in Eucalyptus plantations: a goal programming approach

Abstract

In Galicia (Spain), many Eucalyptus plantations are managed using the area-control method. The ultimate goal is to guarantee an even flow of wood in perpetuity by reaching the normal age-class distribution of the fully regulated forest by the end of a given planning horizon. However, given that the productivity of coppice stands differs throughout the successive rotation intervals, the application of this method triggers excessive fragmentation of the forest area. We present a model with the same long-term goal that does not force plantations into any given final age-class distribution. The model permits the plantations to reach a final structure with fewer harvest units of larger average size. To illustrate this approach, we developed two models and applied them to a case study. The first model used the principle of area control to achieve the fully regulated structure in each site and rotation interval of one full plantation cycle. The second model guaranteed a constant yield beyond the planning horizon without imposing any specific final age distribution on the plantation area. Both models considered objectives such as a constant yield during the planning horizon and the net present value of harvests.