Tree Allometrics

Colophospermum mopane / Root biomass

Mopane root biomass from D²H (RM3)

Root biomassColophospermum mopane · FabaceaeMozambiquenaturalRead from the original paper
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Equation

As printed (Table 6, model RM3, p. 10)

ln(Y) = ln(a) + bln(D2H) + Ɛ RM3 – 2.797 ± 0.306 (– 3.450 to − 2.144) 0.803 ± 0.030 (0.739 to 0.867)

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

Root biomass = exp(-2.797 + 0.803 * ln(D^2 * H))
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Root model with D²H; the D+H model RM2 is left out because its height term is not significantly different from zero (95% CI –0.591 to 1.350). Root biomass (BGB) is stump plus coarse roots from excavation; fine roots under 2 mm were not sampled. n and ranges are not stated separately for the root sample, so they are omitted. No back-transformation correction factor is stated or applied. n = 120 sampled trees (Methods p. 3, Table 3), but Table 5 heads the total-AGB column 'n = 84', so the fitted n may be 84.

Source
RM3 ... R-square 97.80
R² · Table 7, model RM3, p. 10 (printed as a percentage)
R²
0.978
Method
MM-estimator robust regression (ln Y = ln a + b ln(D²H))
Where
Mabalane (Gaza) and Tambara (Manica) districts, mopane woodland
Last checked
2026-11-01
Calculate
Height from
43.8
Root biomass (kg)
20.6
Carbon (kg), ×0.47
75.4
CO₂e (kg), ×44/12
020406080100120140510152025303540DBH (cm)Root biomass (kg)Root 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 = 20, H = 943.843.8Computed from the printed form
computed from the published form

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