Tree Allometrics

Alnus incana / Stem biomass

Grey alder trunk wood (bark excluded) dry mass from DBH (general equation)

Stem biomassAlnus incana · BetulaceaeRussianaturalRead from the original paper
Photo of Alnus incana
© Hladac · CC BY-SA · iNaturalist
Equation

As printed (Eq. 18, p. 68)

M_wood a.d. = 0.0485 · D^2.5138, R² = 0.9196

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

Stem biomass = 0.0485 * D^2.5138
D
Diameter at breast height (1.3 m), cm

General equation fitted on all 21 model trees from four grey alder stands. D is trunk diameter at 1.3 m (cm); output is absolutely dry mass in kg. The last digit of the exponent is clipped in the printed Eq. 20 and 21 (2.3413 and 2.0522 read from the PDF); Table 5 values reproduce within 1% across D = 4 to 16 cm. Per-stand equations in Table 1 are not included. Trunk bark (Eq. 19: 0.0144*D^2.1832, R2 0.7892) has no separate output quantity and is not included. Wood fraction excludes bark.

Source
A total of 21 model trees were studied
Trees measured · Abstract
которые работают при таксационных диаметрах от 4 до 17 см
DBH range · Results, p. 68
Trees measured
21
DBH range
4–17 cm
R²
0.9196
Method
power regression on 21 model trees pooled over 4 stands
Where
Arkhangelsk forestry, North-taiga region, Arkhangelsk oblast
Last checked
2026-11-02
Calculate
1.58
Stem biomass (kg)
0.744
Carbon (kg), ×0.47
2.73
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500600510152025303540DBH (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 = 41.581.58Value printed in the paper
Table 5, p. 73
D = 1015.815.8Value printed in the paper
Table 5, p. 73
D = 1651.651.6Value printed in the paper
Table 5, p. 73

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