Equations / Stem biomass

Commercial stem biomass from DBH and wood density (MB1)

Stem biomass20 commercial tree species of a managed forest (DBH >= 50 cm)BrazilnaturalRead from the original paper

Many species, no single photo

Equation

As printed (Table 1, MB1 (Chave et al. 2005 form))

ln(B) = β0 + β1 ln(d) + β2 ln(p) + ε

In this library's units, ready to compute (kg)

Stem biomass = 1000 * exp(-6.51456) * D^1.93113 * rho^1.317114 * 1.048296

D: Diameter at breast height (1.3 m), cm
rho: Wood density (oven-dry mass / green volume), g/cm³

B is in Mg in the paper (methods: biomass in Mg), converted to kg in the canonical form. p is the species mean basic density (g/cm3). Biomass is commercial stem volume times basic density. R2 is on the log scale. Applies to commercial stems only (stump at 30 cm, buttresses removed, crown left in the forest) of trees with DBH >= 50 cm; do not use for whole-tree totals. The authors selected the equations with commercial stem length l as the best ones; these are the ones that use only canonical variables.

Source

Romero, F. M. B., Jacovine, L. A. G., Ribeiro, S. C., Torres, C. M. M. E., Silva, L. F. da, Gaspar, R. de O., et al. (2020). Allometric Equations for Volume, Biomass, and Carbon in Commercial Stems Harvested in a Managed Forest in the Southwestern Amazon: A Case Study. Forests, 11(8), 874.

doi:10.3390/f11080874 · Open access · copy we read

MB1 −6.51456 * 1.93113 * 1.317114 * 1.296 0.78 753.60 0.857 1.048296

R² · Table 4 (β0, β1, β2, RMSE, R2, AIC, MAD, CF)

Total 223 50.4–149.9 79.6 ± 19.8 0.27–0.89 0.56 ± 0.16

Smallest DBH · Table 2 (n, DBH range and mean, wood density range and mean)

Trees measured: 223
DBH range: 50.4–149.9 cm
R²: 0.78
Correction factor: 1.048296 (applied)
Method: Linear regression on ln(B) vs ln(d) and ln(p), back-transformed with correction factor
Where: Fazenda Antimari I and II, Porto Acre, Acre
Last checked: 2026-11-02

Calculate

DBH (cm)Wood density (g/cm³)

1,965

Stem biomass (kg)

924

Carbon (kg), ×0.47

3,387

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 = 60, rho = 0.56	1,965	1,965	Computed from the printed form computed from the published form (B in Mg times 1000)
D = 100, rho = 0.7	7,071	7,071	Computed from the printed form computed from the published form (B in Mg times 1000)

Report a problem with this equation · JSON

Commercial stem volume from DBH, Husch log model (MV1) · same paper · Stem volume
Commercial stem volume from DBH, Husch power model (MV4) · same paper · Stem volume

Commercial stem biomass from DBH and wood density (MB1)

Related