Long-term impacts of logging in a tropical rain forest - a simulation study

Simulation models for growth of tropical forest can be a useful tool to investigate the long-term impacts of logging. In this paper the rain forest growth model FORMIX3 is used for such a study. As main processes, the FORMIX3 model includes tree growth, mortality, regeneration and competition. The calculation of tree growth is based on a carbon balance approach. Trees compete for light and space; dying large trees fall down and create gaps in the forest. Different logging scenarios for an initially undisturbed forest stand at Deramakot (Malaysia) were simulated. Two different logging methods (conventional and low impact logging) in combination with different cutting cycles (from 20 to 100 years) were investigated for their long-term impact on the forest. We characterize the impacts with four indicators: total yield, yield per cut, species composition, and canopy opening. Our simulation results indicate that too short logging cycles (<40 years) overuse this forest. The corresponding yields are low and the species composition is highly disturbed. For conservation of species composition and minimizing erosion risk, logging cycles of 80 or 100 years in combination with low impact methods are recommended. (C) 2001 Elsevier Science B.V. All rights reserved.