Biomass estimation model for small diameter Auri tree (Acacia auriculiformis A. Cunn. ex Benth.)

Auri (Acacia auriculiformis A. Cunn. ex Benth.) is one of pioneer tree species developed in forest and land rehabilitation. This species can be used as a short-rotation plantation forest for biomass energy source that produces small diameter stem. The potential use of small diameter auri needs to be supported by accurate biomass estimation. This study aims at developing biomass estimation model for young, small diameter auri tree and comparing the local model to generic model. Measurements were carried out on 92 samples of 2-years old auri tree planted with stand densities of 1850-2500 trees/ha. Data was analysed using 8 local models and compared to 5 generic models. Result of the study shows that the best model for estimating small diameter auri biomass is B1 model (B = 0.016(D₂₀)^2.78). The comparison of local and generic models suggested that the local model is better in predicting the auri biomass. This model is valid for small diameter auri species in West Nusa Tenggara Province. This model also seems reliable to apply in similar climatic region, but need a local data validation.