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 inv estigate the long-term impacts of logging. In this paper the rain forest gr owth model FORMIX3 is used for such a study. As main processes, the FORMIX3 model includes tree growth, mortality, regeneration and competition. The c alculation of tree growth is based on a carbon balance approach. Trees comp ete 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 De ramakot (Malaysia) were simulated. Two different logging methods (conventio nal and low impact logging) in combination with different cutting cycles (f rom 20 to 100 years) were investigated for their long-term impact on the fo rest. We characterize the impacts with four indicators: total yield, yield per cut, species composition, and canopy opening. Our simulation results in dicate that too short logging cycles (<40 years) overuse this forest. The c orresponding yields are low and the species composition is highly disturbed . For conservation of species composition and minimizing erosion risk, logg ing cycles of 80 or 100 years in combination with low impact methods are re commended. (C) 2001 Elsevier Science B.V. All rights reserved.