Table 4 Allometric relationships established for poplar and black locust trees at ages 17, 28, 40, and 51 months. Number of trees (n), determination coefficients (R2), and root mean square errors (RMSE) are also indicated. When data did not differ between treatments, trees from the monoculture (Mono) and mixtures (Mix) were combined for the establishment of the relationships. Dv = virtual diameter (mm); H = stem height (cm)
Species | Treatment | Age (months) | Equation | n | R 2 | RMSE | |
|---|---|---|---|---|---|---|---|
Aboveground dry biomass (g) | Poplar | Mix + mono | 17 | 40.86 Dv − 1.859 H − 224.58 | 16 | 0.98 | 29.36 |
Mix + mono | 28 | 0.002733 Dv2H + 401.6 | 16 | 0.85 | 289.4 | ||
Mix + mono | 40 | 0.3764 Dv2.3696 | 16 | 0.92 | 489.5 | ||
Mix + mono | 51 | 225.154 Dv − 7.111 H − 2348.787 | 16 | 0.98 | 550.7 | ||
Black locust | Mix + mono | 17 | − 35.229 Dv + 7.154 H − 278.849 | 16 | 0.70 | 130.9 | |
Mix + mono | 28 | 0.006212 Dv2H + 92.3 | 15 | 0.85 | 298.4 | ||
Mono | 40 | 12.392 Dv + 1.474 | 8 | 0.82 | 451.5 | ||
Mix | 40 | 22.933 Dv + 1.149 | 8 | ||||
Mix + mono | 51 | 150.46 Dv + 3.342 H − 3129.105 | 16 | 0.82 | 1136.6 | ||
Belowground dry biomass (g) | Poplar | Mix + mono | 17 | 6.976 Dv − 0.589 H + 27.873 | 16 | 0.97 | 4.53 |
Mix + mono | 28 | 0.0005875 Dv2H + 123.5 | 15 | 0.74 | 93.33 | ||
Mix + mono | 40 | 0.0008378 D2H + 212.6 | 16 | 0.72 | 220.7 | ||
Mix + mono | 51 | 60.447 Dv + 3.681 H − 51.487 | 16 | 0.97 | 156.0 | ||
Black locust | Mix + mono | 17 | − 25.434 Dv + 2.886 H + 73.571 | 16 | 0.68 | 46.03 | |
Mix + mono | 28 | 0.002498 D2H + 170.5 | 14 | 0.77 | 172.4 | ||
Mono | 40 | 7.1335 Dv1.4746 | 8 | 0.82 | 171.8 | ||
Mix | 40 | 37.8555 Dv0.7618 | 8 | ||||
Mix + mono | 51 | 39.07 Dv + 3.121 H − 1296.275 | 16 | 0.89 | 284.8 | ||
Woody dry biomass (g) | Poplar | Mix + mono | 17 | 39.95 Dv − 2.476 H − 116.456 | 16 | 0.95 | 34.70 |
Mix + mono | 28 | 0.002096 Dv2H + 307.3 | 16 | 0.88 | 201 | ||
Mix + mono | 40 | 0.3328 Dv2.3359 | 16 | ||||
Mix + mono | 51 | 187.343 Dv − 5.754 H − 2050.765 | 16 | 0.97 | 527.4 | ||
Black locust | Mix + mono | 17 | − 44.106 Dv + 7.064 H − 94.291 | 16 | 0.66 | 130.7 | |
Mix + mono | 28 | 0.004772 Dv2H + 112.4 | 15 | 0.89 | 186 | ||
Mono | 40 | 5.462 Dv1.642 | 8 | 0.90 | 248.5 | ||
Mix | 40 | 16.7 Dv1.226 | 8 | ||||
Mix + mono | 51 | 138.704 Dv + 1.43 H − 2596.573 | 16 | 0.83 | 931.6 | ||
Leaf area (cm2) | Poplar | Mix + mono | 17 | 919.397 Dv + 2.807 H − 8271.516 | 16 | 0.97 | 1310 |
Mix + mono | 28 | 0.08214 Dv2H + 11,190 | 15 | 0.90 | 6471 | ||
Mono | 40 | 20.013 Dv2.158 | 8 | 0.91 | 11,971 | ||
Mix | 40 | 404.956 Dv1.355 | 8 | ||||
Mix + mono | 51 | 4527.423 Dv − 176.623 H − 37,990.959 | 16 | 0.98 | 11,296 | ||
Black locust | Mix + mono | 17 | − 1499.256 Dv + 343.852 H − 16,597.968 | 16 | 0.65 | 7264 | |
Mix + mono | 28 | 0.373 D3.7472 | 15 | 0.93 | 8678 | ||
Mono | 40 | 7.4951 Dv2.5952 | 8 | 0.72 | 23,956 | ||
Mix | 40 | 1157.2757 Dv0.6673 | 8 | ||||
Mix + mono | 51 | 5841.87 Dv + 25.658 H − 115,491.008 | 16 | 0.65 | 43,385 | ||
N total (g) | Poplar | Mix + mono | 17 | 0.314 Dv − 0.006 H − 2.179 | 16 | 0.95 | 1.555 |
Mix + mono | 28 | 0.00002824 Dv2H + 5.709 | 16 | 0.85 | 3.126 | ||
Mix + mono | 40 | 0.00002071 Dv2H + 5.356 | 16 | 0.76 | 6.014 | ||
Mix + mono | 51 | 0.475 Dv − 0.023 H + 0.084 | 16 | 0.98 | 0.959 | ||
Black locust | Mix + mono | 17 | − 0.738 Dv + 0.151 H − 6.654 | 16 | 0.72 | 2.662 | |
Mix + mono | 28 | 0.0000481 Dv2H1.10269 | 15 | 0.82 | 5.461 | ||
Mono | 40 | 1.0467 Dv0.6915 | 8 | 0.75 | 9.612 | ||
Mix | 40 | 0.6915 Dv0.929 | 8 | ||||
Mix + mono | 51 | 1.223 Dv + 0.075 H − 32.887 | 16 | 0.78 | 1.281 |