Tree Allometrics

Equations / Stem biomass

Fraxinus angustifolia stem with bark biomass (Table 2)

Stem biomassFraxinus angustifolia · OleaceaeSpainmixedRead from the original paper
Photo of Fraxinus angustifolia
© Nico Hernandez · CC BY · iNaturalist
Equation

As printed (Table 2, Fraxinus angustifolia, Stem row)

Ws = 0.0296 · d² · h

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

Stem biomass = 0.0296 * D^2 * H
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Stem with bark (commercial volume, up to a top diameter of 7 cm); fitted jointly with the branch equations by SUR to keep components additive. Stand type is not stated per species in the paper. Branch equations for this species are not added.

Source
Fraxinus angustifolia ... 26
Trees measured · Table 1, Fraxinus angustifolia row, aboveground biomass n column
Fraxinus angustifolia 7.2 52.2
Smallest DBH · Table 1, diameter min/max (all sample trees of the species)
Trees measured
26
DBH range
7.2–52.2 cm
Height range
2.8–10 m
Method
seemingly unrelated regression with weighting
Where
Spain (sample zones per species, Figure 1)
Last checked
2026-11-02
Calculate
Height from
118.4
Stem biomass (kg)
55.65
Carbon (kg), ×0.47
204
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500510152025303540DBH (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 = 20, H = 10118.4118.4Computed from the printed form
computed from the Table 2 coefficients
D = 35, H = 15543.9543.9Computed from the printed form
computed from the Table 2 coefficients

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