Using multicriteria decision analysis and a forest growth model to assess impacts of tree harvesting in Dipterocarp lowland rain forests

Abstract

Sixty-four different tree-harvesting scenarios in an initially undisturbed Dipterocarp lowland rain forest stand in Sabah (Malaysia) were simulated with the rain forest growth model FORMIND. The scenarios differ in terms of their minimum cutting diameter, logging cycle, method and intensity. The simulation results include harvest yields and the impact on forest structure (canopy opening and changes in species composition). Multicriteria decision analysis was used to evaluate the scenarios and identify optimum ones by applying a stochastic extension of the PROMETHEE method. Almost all optimum scenarios used reduced-impact logging. High cutting limits or low logging intensities could not compensate for the high damage caused by conventional logging techniques. Five scenarios proved to be optimum for a wide range of priorities concerning different forest functions. They all use reduced-impact logging and long logging cycles (≥60 years), either with a minimum cutting limit of 50 or 60 cm stem diameter, or with medium logging intensities.