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Table 3 Parameter estimates for the BASE, GB99 and M3_HABH taper models

From: Use of upper stem diameters in a polynomial taper equation for New Zealand radiata pine: an evaluation

Parameter Estimate
BASE model Model GB99 Model M3_HABH
β 1 T-S T-S T-S
β 2 T-S T-S
β 21 0.0929 (0.0130)
β 3 0.4125 (0.0189) 0.5502 (0.0053)
β 30 0.8213 (0.0351)
β 31 −0.2040 (0.0199)
γ 1 1.4420 (0.0061) 1.7149 (0.0440)
γ 10 0.9377 (0.0237)
γ 11 0.3522 (0.0169)
γ 2 16.6627 (2.4157) 14.5371 (0.6206) 2.1955 (0.1190)
γ 3 64.2933 (3.0251) 34.3438 (0.4982)
γ 31 1.3431 (0.0351)
  1. The standard errors of the parameter estimates are given in parentheses. For the BASE model, parameter β 1 is constrained to dbh, and for models M3_HABH and GB99, parameter β 1 is constrained to dbh and β 2 to the upper stem diameter (diameter at 6 m for the GB99 model). The estimates for the constrained parameters are tree-specific (T-S). The parameter estimates given were all statistically significant (p ≤ 0.0001). Residual correlation parameters are not included because they are not important for model prediction purposes