Equations / Aboveground biomass
Pantropical AGB without height, with stress index E (Eq. 7)
Aboveground biomassTropical trees (58 sites)PantropicalnaturalRead from the original paper
Many species, no single photo
Equation
As printed (Eq. 7, p. 3183)
AGBest = exp[−1.803 − 0.976E + 0.976 ln(ρ) + 2.673 ln(D) − 0.0299[ln(D)]²]
In this library's units, ready to compute (kg)
Aboveground biomass = exp(-1.803 - 0.976 * E + 0.976 * ln(rho) + 2.673 * ln(D) - 0.0299 * (ln(D))^2)E- Environmental stress index (Chave et al. 2014)
rho- Wood density (oven-dry mass / green volume), g/cm³
D- Diameter at breast height (1.3 m), cm
Use when height is not measured. E from Eq. 6b / the authors' gridded layer. Printed as AGBest under the paper's Eq. 2 convention (estimator includes exp(σ²/2)); no further correction applied. Note: the BIOMASS R package uses refitted coefficients for this model, not these printed ones.
Source
doi:10.1111/gcb.12629 · Paywalled · copy we read
(AIC = 4293, σ = 0.413, df = 3999)
We therefore propose Model 7 for estimating AGB in the absence of height measurements.
where D is in cm, H is in m, and ρ is in g cm−3
4004 trees ≥ 5 cm trunk diameter
for a total of 4004 trees with trunk diameter ranging from 5 to 212 cm
- Trees measured
- 4,004
- DBH range
- 5–212 cm
- Residual SE
- 0.413
- Method
- log-scale regression on E, ln(ρ), ln(D), ln(D)²
- Where
- 58 harvest sites across the tropics
- Last checked
- 2026-11-01
Calculate
628.9
Aboveground biomass (kg)
295.6
Carbon (kg), ×0.47
1,084
CO₂e (kg), ×44/12
Shaded: the DBH range the model was fitted on. Other inputs held at the values above.
Checks this equation passes
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 |
|---|---|---|---|
| D = 30, rho = 0.6, E = 0 | 628.9 | 628.9 | Computed from the printed form computed with python3 from the published form |
| D = 30, rho = 0.6, E = 0.5 | 386 | 386 | Computed from the printed form computed with python3 from the published form |
Related
- Pantropical AGB with height (Eq. 4) · Chave et al. 2014 · Wood density + DBH + Height
- Pantropical AGB with height, exponent fixed at 1 (Eq. 5) · Chave et al. 2014 · Wood density + DBH + Height
- Pantropical AGB with height (Eq. 4) · same paper · Aboveground biomass
- Pantropical AGB with height, exponent fixed at 1 (Eq. 5) · same paper · Aboveground biomass
- Pantropical height–diameter model with stress index E (Eq. 6a) · same paper · Height