Tree Allometrics

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Khaya senegalensis stem biomass from Dbh

Stem biomassKhaya senegalensisBeninnaturalRead from the original paper
Photo of Khaya senegalensis
© jayeshpatil912 · CC BY · iNaturalist
Equation

As printed (Eq. 3 and 5, p. 7; Table 4 (Model structure: ln(X) = x0 + x1ln(Dbh)), p. 10)

K. senegalensis –2.50*** (0.16) 2.40*** (0.06) 98.56 22 0.02 25

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

Stem biomass = exp(-2.5 + 2.4 * ln(D) + 0.02)
D
Diameter at breast height (1.3 m), cm

Stem biomass only (stem = height to crown base); the authors say to multiply by a biomass expansion factor (IPCC 2006) to get aboveground biomass. Coefficients are printed to 2 decimals, so predictions are only as precise as that. σ²/2 is the paper's printed bias-correction term, added inside the exponent (Eq. 5); it is printed rounded to 2 decimals. Recommended-to-capture subset: species-specific Dbh-only biomass models for six species; the paper prefers species-specific models over the generic one.

Source
Khaya senegalensis 27 160 3.7–40.2
Trees measured · Table 1, p. 5 (number of sample trees)
Khaya senegalensis 27 160 3.7–40.2
Smallest DBH · Table 1, p. 5 (Dbh range, cm)
Trees measured
27
DBH range
3.7–40.2 cm
Method
ln-ln linear regression, back-transformed with exp(σ²/2) (printed σ²/2 is rounded to 2 decimals)
Where
Lama forest reserve, southern Benin (semi-deciduous forest)
Last checked
2026-11-02
Calculate
111
Stem biomass (kg)
52.18
Carbon (kg), ×0.47
191.3
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500600510152025303540DBH (cm)Stem biomass (kg)Stem biomass

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%.

InputsExpectedWe getFrom
D = 20111111Computed from the printed form
computed from the published form (coefficients as printed to 2 decimals)
D = 40586586Computed from the printed form
computed from the published form (coefficients as printed to 2 decimals)

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