This study was conducted to evaluate tree height-diameter at breast height (DBH) models for the three tropical plantation species in the Philippines, namely: Gmelina (Gmelina arborea Roxb.), Mahogany (Swietenia macrophylla King) and Mangium (Acacia mangium Willd.) using the seven commonly used nonlinear growth models. The data used in this study were acquired from the different plantation areas. To evaluate the models developed, coefficient of determination (R2), root mean square error (RMSE), mean difference (MD) and absolute mean difference (AMD) were used as performance criteria for each species and model. Results showed that the R2 of all models in all three species ranged from 0.812 to 0.942 while the RMSE ranged from 1.755 to 3.024 m. On the other hand, the overall MD ranged from -0.035 to 0.142 m while the AMD ranged from 1.460 to 2.422 m. All models were able to determine the relationships between height and DBH and fit the data well with the exception of the Korf/Lundqvist and Schnute model for A. mangium. Furthermore, the Exponential model was the best model for the G. arborea and A. mangium, whereas the best model for the S. macrophylla was the Korf/Lundqvist model based on the four performance criteria using the rank analysis.

Key words: nonlinear growth functions, height-DBH models, Acacia mangium, Gmelina arborea, Swietenia macrophylla, Philippines