Research Article
Site-Species Allometry Equation for Theobroma cacao L. Biomass Estimation in Agroforestry Systems of Cameroon
Table 3
Comparison of the models in this study with models commonly used to calculate the biomass of Theobroma cacao.
| Authors | Model | RRMSE | Residual error (%) | Biomass (kg) |
| Aboveground biomass (AGB) | Chave et al. [18] | AGB (kg) = 0.0673 × (ρ D2H)0.976 | 0.339 | −3.34 | 1618.65 | Chave et al. [20] | AGB (kg) = 0.0509 × ρ D2H | 0.350 | −15.273 | 1440.26 | Somarriba et al. [22] | Log AGB (kg) = (−1.684 + 2.158 × log (d30) + 0.892 × log (alt)) | 0.82 | −81.88 | 207.74 | Model 1 | ln B = −1.613 + 1.83 × ln (D) | 0.198 | 3.47 | 1421.56 | Model 6 | ln B = −1.598 + 1.628 × ln (D) + 0.36 × ln (C) | 0.190 | 3.21 | 1426.075 | Observed biomass | — | — | — | 1419.874 |
| Belowground biomass (BGB) | IPCC [35] | BGB = Chave et al. [18] × 0.24 | 0.514 | 6.991 | 388.48 | IPCC [35] | BGB = Chave et al. [20] × 0.24 | 0.468 | −6.076 | 345.66 | IPCC [35] | BGB = Somarriba et al. [22] × 0.24 | 0.81 | −80.79 | 49.86 | Model 1 | ln B = −2.611 + 1.655 × ln (D) | 0.316 | 7.92 | 315.47 | Model 5 | ln B = −2.564 + 0.64 × ln (D2 × C) | 0.294 | 7.20 | 316.84 | Observed biomass | — | — | — | 316.693 |
| Total biomass (TB) | IPCC [35] | TGB = Chave et al. [18] × (1 + 0.24) | 0.348 | −2.877 | 2007.128 | IPCC [35] | TGB = Chave et al. [20] × (1 + 0.24) | 0.356 | −14.834 | 1785.92 | IPCC [35] | TGB = Somarriba et al. [22] × (1 + 0.24) | 0.822 | −80.67 | 257.60 | Model 1 | ln B = −1.297 + 1.79 × ln (D) | 0.169 | 2.68 | 1732.12 | Model 6 | ln B = −1.278 + 1.57 × ln (D) + 0.37 × ln (C) | 0.158 | 2.41 | 1738.01 | Observed biomass | — | — | — | 1736.567 |
|
|