Equations / Aboveground biomass
Native shrubs NZ (3 spp, all sites): AGB from D (Table 7)
Fitted on these 3 species: Coprosma robusta, Pittosporum crassifolium, Melicytus ramiflorus
As printed (Table 7)
In this library's units, ready to compute (kg)
Aboveground biomass = 1.07 * exp(-3.69 + 2.45 * ln(DRC))DRC- Root collar / stem base diameter, cm
AGB is the sum of stem, branch and foliage dry biomass of the shrub. Natural log. D is the basal stem diameter over bark about 10 cm above ground (multi-stemmed shrubs: square root of the sum of stem diameters), mapped to DRC; H is total height in m. Table 7 reports adjusted R2 = 0.881 and RMSE = 0.337 (not used as r2 or rse). Shrubs had basal diameter up to 10 cm (mean D 3.4 to 3.8 cm by species, Table 4); the paper prints no D range for these models. The CF column is the factor the paper applies to back-transformed predictions.
doi:10.33494/nzjfs562026x567x · Open access · copy we read
CF = e(RSE²/2) Equation 2; Table 7 CF column 1.07
- Trees measured
- 54
- Correction factor
- 1.07 (applied)
- Method
- OLS regression on natural logarithms (power form), back-transformed with correction factor CF = exp(RSE^2/2)
- Where
- Limestone Downs (Waikato west coast) and Massey University sites, Manawatu-Waikato
- Last checked
- 2026-11-02
On every build, the library's form and the paper's own form (in its units) must both give these values within 1%.
| Inputs | Expected | We get | From |
|---|---|---|---|
| DRC = 2 | 0.146 | 0.146 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
| DRC = 4 | 0.798 | 0.798 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
| DRC = 8 | 4.36 | 4.36 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
Related
- Native shrubs NZ (3 spp, Massey University): AGB from D and H (Table 7) · Wangui et al. 2026 · Root collar diameter + Height
- Coprosma robusta (all sites): AGB from D and H (Table 7) · same paper · Aboveground biomass
- Coprosma robusta (Massey University): AGB from D and H (Table 7) · same paper · Aboveground biomass
- Native shrubs NZ (3 spp, Massey University): AGB from D and H (Table 7) · same paper · Aboveground biomass
- Melicytus ramiflorus (Limestone Downs): AGB from D (Table 7) · same paper · Aboveground biomass
- Pittosporum crassifolium (Massey University): AGB from D and H (Table 7) · same paper · Aboveground biomass