Table 6. Model description of root biomass (RB) estimates.
| No | Model | Adjusted R2 | RSE | AIC | S% | CF |
|---|---|---|---|---|---|---|
| 1 | ln(RB) = a + bln(DBH) | 0.790 | 0.391 | -75.16 | 30.7 | 1.079 |
| 2 (-) | ln(RB) = a + bln(DBH) + e(ln(DBH))2 | 0.785 | 0.396 | -75.16. | 30.8 | 1.081 |
| 3 (-) | ln(RB) = a + bln(DBH) + dln(H) | 0.789 | 0.392 | -73.93 | 30.7 | 1.079 |
| 4 (-) | ln(RB) = a + bln(DBH) + cln(WD) + dln(H) | 0.856 | 0.324 | -88.26 | 22.2 | 1.053 |
| 5 (-) | ln(RB) = a + bln(DBH) + e(ln(DBH))2 + f(ln(DBH))3 + cln(WD) | 0.854 | 0.326 | -87.73 | 22.5 | 1.054 |
| 6 | ln(RB) = a + bln(DBH2HWD) | 0.854 | 0.326 | -85.48 | 23.3 | 1.054 |
| 7 | ln(RB) = a + bln(DBH) + cln(WD) | 0.857 | 0.323 | -89.52 | 22.8 | 1.053 |
| 8 | ln(RB) = a + bln(DBH2H) + cln(WD) | 0.854 | 0.326 | -86.61 | 22.3 | 1.054 |
| 9 | ln(RB) = a + bln(AGB) | 0.860 | 0.322 | -90.6 | 25.5 | 1.053 |
DBH, H, WD and AGB are predictors of the models and indicate stem diameter at breast height, tree height, wood density and above ground biomass, respectively. The results are significant at a 95% confidence interval. RSE: residual standard errors of estimate, AIC: Akaike Information Criterion, S%: average standard error of the estimate, CF: correction factor, (-) indicates the model has a predictor that was not significantly different from 0.