Tree Allometrics

Pinus radiata / Stem biomass

Radiata pine stemwood from DBH²H (Eq. 10)

Stem biomassPinus radiata · PinaceaeSouth AfricaplantationRead from the original paper
Photo of Pinus radiata
© Forest and Kim Starr · CC BY · iNaturalist
Equation

As printed (Table 3)

Stemwood, Eq. 10, Ln(DBH2H): β0 = -3.607, β1 = 0.911, CF = 1.029

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

Stem biomass = 1.029 * exp(-3.607 + 0.911*ln(D^2*H))
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Natural-log model; correction factor CF = exp(RSE²/2) (Baskerville) as printed in Table 3 is applied in the expression. H is total tree height (m). Stand-level site: 4 plantation sites aged 13 to 20 years. Biomass is oven-dry mass. Eq. 10 is the authors' best model for stemwood and total. Stemwood (SW) is stem wood without bark; bark is a separate component in Table 3 and is not included here. Table 1 lists 19 stemwood (SW) values against 20 felled trees, so n for the stemwood models is not stated unambiguously and is left out.

Source
ln (Y) = β0 + β1ln(X1) + ⋯ + βjln(Χj) needs to be multiplied by the CF to transform the values to the arithmetic scale
Equation · Table 3 footnote
R2 = 0.91
R² · Table 3
the sample trees in this study range from 10.4 cm to 38.9 cm
Smallest DBH · Discussion
DBH (cm) 20 38.9 10.4 24.5 8.3; H (m) 20 25.52 10.88 16.78 3.89 (n, Max, Min, Mean, SD)
h min m · Table 1, Upscaling II
DBH range
10.4–38.9 cm
Height range
10.88–25.52 m
R²
0.91
Correction factor
1.029 (applied)
Method
ln-ln linear regression (R lm), Baskerville correction factor
Where
Boland region, Western Cape, South Africa
Last checked
2026-11-02
Calculate
Height from
42.9
Stem biomass (kg)
20.2
Carbon (kg), ×0.47
74
CO₂e (kg), ×44/12
Fitted DBH range050100150200250300510152025303540DBH (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 = 15, H = 1442.942.9Computed from the printed form
computed from the published form
D = 30, H = 22229229Computed from the printed form
computed from the published form

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