Equations / Aboveground biomass
Pittosporum crassifolium (Massey University): AGB from D and H (Table 7)
Jenny Christianson · CC0 · iNaturalistAs printed (Table 7)
In this library's units, ready to compute (kg)
Aboveground biomass = 1.0 * exp(-3.65 + 3.93 * ln(DRC) + -2.4 * ln(H))DRC- Root collar / stem base diameter, cm
H- Total tree height, m
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 = 0.996 and RMSE = 0.038 (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 1.0
- Trees measured
- 5
- Correction factor
- 1 (applied)
- Method
- OLS regression on natural logarithms (power form), back-transformed with correction factor CF = exp(RSE^2/2)
- Where
- Massey University natural reserves and Dairy4 farm trial site
- 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, H = 1 | 0.396 | 0.396 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
| DRC = 4, H = 2 | 1.14 | 1.14 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
| DRC = 8, H = 3 | 6.59 | 6.59 | Computed from the printed form computed from the published form (a is ln(a), CF applied, coefficients as printed) |
Related
- Pittosporum eugenoides, NZ, total aboveground biomass from RCD (Table 3) · Marden et al. 2025 · Root collar diameter
- Pittosporum tenuifolium, NZ, total aboveground biomass from RCD (Table 3) · Marden et al. 2025 · Root collar diameter
- 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, all sites): AGB from D (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