Tree Allometrics

Pinus sylvestris / Stem biomass

Scots pine stem biomass, young dense stands, N Sweden (Table 5)

Stem biomassPinus sylvestris · PinaceaeSwedennaturalRead from the original paper
Photo of Pinus sylvestris
© Douglas Goldman · CC BY-SA · iNaturalist
Equation

As printed (Table 5, p. 12)

Stem, kg, Scots pine: Intercept −3.010; dbh/(dbh + n) 7.999; h/(h + m) 2.959; n 8; m 13; var(uk) 0.003; var(eki) 0.018

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

Stem biomass = exp(-3.010 + (0.003 + 0.018) / 2 + 7.999 * D / (D + 8) + (2.959) * H / (H + 13))
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Fitted on pine-dominated mixed stands; fit n, DBH and height ranges are the species sample ranges. Expression applies the paper's stated additive correction (var(uk) + var(eki))/2 to the intercept. Variance values are as printed in Table 5; no other correction factor is stated.

Source
a variance correction term, ((var(uk) + var(eki))/2) should be added to the intercept to correct for bias due to the logarithmic transformation
Equation · Section 2.6, p. 10
In total, 280 trees were included in this destructive aboveground biomass study, of which 126 were pine, 68 spruce and 86 birch.
Trees measured · Section 2.4, p. 6
The range of dbh was 1–22 cm, 1–21 cm and 1–11 cm for pine, spruce and birch, respectively
Largest DBH · Section 2.4, p. 6
The range of heights was 1.7–11.7 m, 1.6–13.3 m and 1.8–8.6 m for pine, spruce and birch, respectively
h max m · Section 2.4, p. 6
Trees measured
126
DBH range
1–22 cm
Height range
1.7–11.7 m
Method
linear mixed model of ln(biomass) with random stand effect; ln(y) = Intercept + b1 dbh/(dbh + n) + b2 h/(h + m)
Where
Six young, dense, naturally regenerated stands in northern Sweden (63.26-65.69 N)
Last checked
2026-11-02
Calculate
Height from
2.46
Stem biomass (kg)
1.15
Carbon (kg), ×0.47
4.23
CO₂e (kg), ×44/12
Fitted DBH range020406080100510152025303540DBH (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 = 5, H = 52.462.46Computed from the printed form
hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction
D = 12, H = 920.320.3Computed from the printed form
hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction

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