SUSTAINABLE TIMBER HARVESTING - SIMULATION STUDIES IN THE TROPICAL RAIN-FORESTS OF NORTH QUEENSLAND

Although logging ceased in the tropical rainforests of north Queenslan d following their World Heritage Listing in 1988, they provide a good basis for simulation studies on sustainability of timber harvesting as reliable logging records, inventory and growth data are available. A growth model for these forests has been developed and published. The g rowth model is dynamic, responding to changes in stand density, compos ition and management history. A harvesting simulator predicts the tree s removed by selection logging, and predicts changes in the residual s tand. Simulation studies employ cutting cycle analysis and yield sched uling to demonstrate the sustainability of harvesting. These studies i ndicate that selection harvesting could sustain a viable timber harves t of about 60000 m(3) year(-1). These results are indicative rather th an definitive, as the model has not yet been formally validated with i ndependent data.