Tree Allometrics

Equations / Branch biomass

Oak branch biomass from D and crown width, additive system 2 (Table 4)

Branch biomassQuercus (Q. mongolica and Q. wutaishanica) · FagaceaeChinanaturalRead from the original paper
Covers the whole genus
Equation

As printed (Table 4, System 2)

Branch Wbr = 0.017D2.156CW0.870

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

Branch biomass = 0.017 * D^2.156 * CD^0.870
D
Diameter at breast height (1.3 m), cm
CD
Crown diameter, m

Fitted on 120 Mongolian oak and 39 Liaodong oak trees (Table 1; D 1.5-33.0 cm). Exponents are printed flattened in the HTML text; read as D^exponent. No R2 recorded (adjusted R2 only). CW is crown width (twice the mean crown radius); mapped to canonical CD (crown diameter). Crown width range 0.45-9.70 m (Table 1).

Source
A total of 159 sample trees
Trees measured · Abstract
Trees measured
159
DBH range
1.5–33 cm
Height range
1.4–20.5 m
Method
weighted nonlinear seemingly unrelated regression (NSUR), additive system
Where
Daxing'anling, Xiaoxing'anling and Changbai mountains, NE China
Last checked
2026-11-02
Calculate
0.777
Branch biomass (kg)
0.365
Carbon (kg), ×0.47
1.34
CO₂e (kg), ×44/12
Fitted DBH range010203040506070510152025303540DBH (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 = 5, CD = 1.50.7770.777Computed from the printed form
computed from the published form (coefficients as printed)
D = 15, CD = 3.517.417.4Computed from the printed form
computed from the published form (coefficients as printed)
D = 28, CD = 6106.5106.5Computed from the printed form
computed from the published form (coefficients as printed)

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