Tree Allometrics

Populus balsamifera / Stem biomass

Canadian national equation, balsam poplar, dbh only (stem wood plus stem bark; Table 3)

Stem biomassPopulus balsamifera · SalicaceaeCanadaRead from the original paper
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Equation

As printed (Eq. 2)

y wood = β wood1D βwood2 + ewood

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

Stem biomass = 0.051 * D^2.4529 + 0.0297 * D^2.1131
D
Diameter at breast height (1.3 m), cm

Stem from ground level to tree top, stem wood plus stem bark; the stem is the sum of the two compartment equations. r2 is the adjusted R² (AdjRSq) of this compartment in Table 5. Fitted on the original scale (weighted nonlinear seemingly unrelated regression), so there is no back-transform correction. Dead branches, cones and fruits are not part of aboveground biomass in this work (Materials). Stand type was not always recorded. Ung, Bernier & Guo (2008) later revised parameters for some species with British Columbia data; not used here.

Source
y bark = β bark1D βbark2 + e bark
Equation · Eq. 2
Balsam poplar bwood1 0.0510
Equation · Table 3, Balsam poplar
bwood2 2.4529
Equation · Table 3, Balsam poplar
bbark1 0.0297
Equation · Table 3, Balsam poplar
bbark2 2.1131
Equation · Table 3, Balsam poplar
Balsam poplar 207 21.5±0.8 16.3±0.4 199.6±16.1
Trees measured · Table 2 (No. of trees)
(2.0;53.2) (3.3;27.0) (0.5;1516.3)
Smallest DBH · Table 2, Balsam poplar (ranges of dbh, height, total biomass)
Stem 0.0054 0.92 54.6 3.90 0.0149 0.95 43.4 3.39
R² · Table 5, Balsam poplar (AdjRSq in the dbh-based set, first block)
Trees measured
207
DBH range
2–53.2 cm
R²
0.92
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Canada: Alberta, Manitoba, Northwest Territories, Ontario, Saskatchewan (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
95.9
Stem biomass (kg)
45.1
Carbon (kg), ×0.47
165
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 = 2095.995.9Computed from the printed form
computed from the published form at dbh = 20 cm

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