Das ideale Plentergleichgewicht – Leitbild oder Luxus? (Essay) | The ideal equilibrium state in a selection forest – vision or luxury? (essay)

Abstract

In managing unevenly aged forests, conventional ideal equilibrium models based on curves of declining stem numbers have relied on the overall concept of a simultaneous fulfilment of various aims. The study presented here investigated whether such models are adaptable to current economic conditions and to what extent financial objectives could be optimized without infringing on structural requirements. A linear, time discrete equilibrium model calibrated with data collected from a sample area within a Swiss selection forest was combined with a linear optimization model. Financial objectives were optimized in numeric experiments under a range of strictness values for stand-structure constraints. The results were compared with those obtained from an exemplary conservative ideal model. This evaluation found system equilibria far from that reference, and it also found some wich could generate a much higher income. However, the most meaningful increase of the target variable could be realized without requiring any critical deviation from the compared model. This could be accomplished by augmenting the current growing stock while reducing the maximum diameter at breast height. Therefore, management interventions that incur losses could be abandoned in the lower diameter classes, and only trees above a specified diameter would then be harvested. In applying this new model, the decision makers would be asked to thoroughly analyze their management objectives and the given restrictions on acting accordingly. Hence, they could immediately provide arguments to justify their decisions.