Tree Allometrics

Vachellia tortilis / Branch biomass

Vachellia tortilis branch biomass (Model 5)

Branch biomassVachellia tortilisEthiopiaRead from the original paperPeer-reviewed sourceNot fully checked

Not fully checked: Table 5 gives M5 as a DBH-and-height model, while Table 1 defines M5 as stump diameter squared. This record uses Table 5; confirm the intended form and coefficients with the authors before relying on it.

Photo of Vachellia tortilis
© Rabah Al-Shammary · CC BY · iNaturalist
Equation

As printed (Table 5, Models and Coefficients columns, Branch Model 5 row, p. 9)

Y = β₁d^β₂h; β₁ = 0.107, β₂ = 1.678

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

Branch biomass = 0.107 * D^1.678 * H
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Nonlinear power regression on the original scale; no back-transformation or correction is stated or applied. d is diameter at breast height, 1.3 m, and h is total height. For multi-stemmed trees use the square root of the sum of squared stem diameters at the relevant height (Eq. 1). The harvested stump-diameter range was 3.2–44.5 cm. This record uses the component-specific form in Table 5.

Source
Model 5 Y = β1d β 2 h 0.107 1.678*** 0.87 51.985 − 0.221 36.294 0.75 2
Equation · Table 5, Branch Model 5, p. 9
Branch
Output · Table 5, biomass component, p. 9
biomass (kg dry matter/
Units · Table 5 heading, p. 9
ith stem at stump or breast height (cm).
Units · Eq. 1 definition, p. 4
d: diameter at breast height (1.30 m)
Units · Table 5 note, p. 9
height of plant (m)
Units · Table 5 note, p. 9
kg per plant, n: 15
Trees measured · Table 5 note, p. 9
Model 5 Y = β1d β 2 h 0.107 1.678*** 0.87 51.985 − 0.221 36.294 0.75 2
R² · Table 5, Branch Model 5, p. 9
non-linear power function
method · Abstract, p. 1
Vachellia tortilis
Taxon · Study area, p. 3
Adami Tullu Jido Kombolcha district
Where · Study area, p. 2
semi-arid climate zone
Where · Study area, p. 2
Trees measured
15
R²
0.87
Method
nonlinear power regression
Where
Adami Tullu Jido Kombolcha district, Central Rift Valley, Ethiopia
Last checked
2026-11-05
Calculate
Height from
30.2
Branch biomass (kg)
14.2
Carbon (kg), ×0.47
52
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%.

InputsExpectedWe getFrom
D = 15, H = 330.230.2Computed from the printed form
Computed from the printed Table 5 coefficients; no individual published prediction with all inputs is provided.

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