A forest simulation model for predicting eucalypt dynamics and habitat quality for arboreal marsupials
JULI G. PAUSAS,1,3 MIKE P. AUSTIN,1 AND IAN R. NOBLE2
1CSIRO Division of Wildlife and Ecology, PO Box 84, Lyneham, A. C.T. 2602, Australia
2Research Schools of Biological Sciences, The Australian National University, Canberra, A. C.T. 0200, Australia
A forest simulation model (called EDEN) of eucalypt dynamics in south-eastern Australia is presented to predict habitat quality for arboreal marsupials. The model is presented as a tool for testing alternative hypotheses of forest management in the study area. EDEN uses a forest gap simulation (JABOWA/FORET type) model as a pattern generator of habitat in different landscape positions and under different harvesting regimes and predicts the habitat quality of this habitat for arboreal marsupials. Application of the model is illustrated by simulating four environmental scenarios (gullies and ridges, at low and at high soil nutrient levels) and three harvesting regimes for each environmental scenario (no harvesting, low-intensity harvesting, and high-intensity harvesting). The changes in tree species composition and diversity and the changes in habitat quality for the arboreal marsupials are presented for the 12 scenarios. The predicted vegetation composition is different in the different environmental scenarios and agrees with empirical studies, suggesting that EDEN is a useful pattern generator in the study area. The simulation results suggest that there may be a harvesting level for which the habitat quality is not significatively reduced, but this will depend on the landscape position. The decline in habitat quality with increasing harvesting is stronger on ridges than in gullies.