Tree Allometrics

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Planted Acacia mangium, West Java, branch biomass from D, all ages (model B)

Branch biomassAcacia mangium · FabaceaeIndonesiaplantationRead from the original paper
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Equation

As printed (Table 3, model B, stand age 3-10)

Y = a·dbh^b; a = 0.0046, b = 2.8669, r2 = 0.9359

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

Branch biomass = 0.0046 * D^2.8669
D
Diameter at breast height (1.3 m), cm

Model B (the authors' recommended general equation): all four stand ages combined (3-10 yr). Fitted in log space (log-linear) and printed as a power law; the paper states no back-transformation correction factor and none is applied. The paper does not print the sampled dbh range. Branch biomass (Yb) includes dead branches still attached to the tree, as defined by the authors (p. 72).

Source
We selected 15 trees from the 3-year-old stand, 12 trees from the 5-year-old stand, 16 trees from the 8-year-old stand, and 16 trees from the 10-year-old stand
Trees measured · Destructive Sampling to Measure the Biomass of Individual Trees, p. 72
Trees measured
59
R²
0.9359
Method
log-linear least squares of Y = a·dbh^b
Where
Maribaya and Tenjo ranger districts (Parungpanjang), Perhutani, West Java
Last checked
2026-11-02
Calculate
0.464
Branch biomass (kg)
0.218
Carbon (kg), ×0.47
0.8
CO₂e (kg), ×44/12
050100150200510152025303540DBH (cm)Branch biomass (kg)Branch 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 = 50.4640.464Computed from the printed form
computed from the published form (coefficients as printed)
D = 103.393.39Computed from the printed form
computed from the published form (coefficients as printed)
D = 2024.724.7Computed from the printed form
computed from the published form (coefficients as printed)

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