Table 4 Non-linear models describing relationships between forest stand characteristics (predictors) and tree stand biomass (Mg ha−1)
From: Tree and stand level estimations of Abies alba Mill. aboveground biomass
Component | Predictor | Equation | a | SE | b | SE | RMSE | R 2 | AIC | AIC0 |
|---|---|---|---|---|---|---|---|---|---|---|
Aboveground | Age | 14 | 15.5976 | 10.4750 | 0.6230 | 0.1538 | 9.770 | 0.773 | 131.541 | 147.325 |
BA | 16 | 338.4602 | 51.0512 | − 4509.9619 | 1602.4894 | 12.021 | 0.658 | 126.535 | ||
N | 14 | 2448.9150 | 1579.5938 | − 0.3895 | 0.1055 | 8.350 | 0.695 | 135.095 | ||
D | 16 | 299.9651 | 20.2692 | − 1831.4091 | 314.6267 | 4.083 | 0.865 | 116.305 | ||
H g | 14 | 12.3859 | 6.4909 | 0.9005 | 0.1588 | 4.726 | 0.916 | 119.557 | ||
V | 14 | 0.6978 | 0.4328 | 0.9397 | 0.0995 | 6.597 | 0.977 | 97.075 | ||
Branches | Age | 14 | 1.8046 | 1.5111 | 0.6331 | 0.1916 | 0.532 | 0.678 | 85.878 | 97.469 |
BA | 16 | 35.6780 | 8.0444 | − 362.9002 | 252.5116 | 3.615 | 0.459 | 85.882 | ||
N | 14 | 353.6486 | 249.9720 | − 0.4176 | 0.1163 | 0.465 | 0.672 | 86.097 | ||
D | 14 | 2.5502 | 1.7724 | 0.6983 | 0.1989 | 2.812 | 0.784 | 75.800 | ||
H g | 14 | 1.2832 | 1.1028 | 0.9472 | 0.2600 | 0.374 | 0.806 | 79.783 | ||
V | 14 | 0.0876 | 0.1719 | 0.9321 | 0.3148 | 0.439 | 0.783 | 75.851 | ||
Foliage | Age | 16 | 21.6134 | 1.9509 | − 142.0926 | 41.9580 | 0.000 | 0.534 | 76.089 | 83.257 |
BA | 14 | 3.0297 | 3.3855 | 0.5050 | 0.3065 | 3.758 | 0.728 | 65.275 | ||
N | 14 | 31.4709 | 23.2029 | − 0.0908 | 0.1109 | 0.047 | 0.075 | 84.317 | ||
D | 16 | 20.0025 | 2.3108 | − 26.5623 | 35.8690 | 5.006 | 0.635 | 68.532 | ||
H g | 16 | 19.4517 | 1.3691 | − 13.5397 | 3.2128 | 0.000 | 0.640 | 73.005 | ||
V | 16 | 20.0868 | 1.5910 | − 354.2706 | 232.9451 | 3.980 | 0.692 | 66.667 | ||
Stem | Age | 14 | 8.8797 | 6.6859 | 0.6985 | 0.1714 | 9.334 | 0.786 | 126.840 | 143.324 |
BA | 16 | 273.1988 | 46.3089 | − 3842.5472 | 1453.6294 | 5.493 | 0.607 | 124.390 | ||
N | 14 | 2450.7612 | 1709.8093 | − 0.4286 | 0.1151 | 8.825 | 0.712 | 130.398 | ||
D | 16 | 243.2335 | 17.8532 | − 1615.2956 | 277.1247 | 3.093 | 0.854 | 113.513 | ||
H g | 14 | 5.6214 | 3.5196 | 1.0691 | 0.1887 | 4.331 | 0.920 | 115.081 | ||
V | 14 | 0.1367 | 0.0742 | 1.1638 | 0.0868 | 3.711 | 0.989 | 85.550 |