DBH-height modeling and validation for Acacia mangium and Eucalyptus pellita in Korintiga Hutani Plantation, Kalimantan, Indonesia

Abstract

Diameter at breast height (DBH)-height models were developed and validated for Acacia mangium and Eucalyptus pellita species in the tree plantation of Pangkalan Bun, central Kalimantan, Indonesia, using the six commonly used nonlinear growth models. A total of 2992 and 4511 total height and DBH measurements were used for A. mangium and E. pellita species, respectively. These data were randomly split into two datasets. The majority of the data (80%) were used for the initial model development and the remaining data (20%) were applied for model validation. The combined data (100%) were used for the final model development. For model validation, the bias () for each DBH class (5 cm interval) and the overall bias were determined. The performance of the developed models were evaluated and ranked using the coefficient of determination (R2), root mean square error (RMSE), bias, absolute mean difference (AMD) and Furnival index (FI). The Weibull model had the best performance followed by the Chapman-Richards model in predicting the total height of A. mangium species and for E. pellita, the Korf/Lundqvist and Chapman-Richards models were the best models based on the evaluation statistics and rank analysis.