Tree Allometrics

Pinus banksiana / Stem biomass

Canadian national equation, jack pine, dbh only (stem wood plus stem bark; Table 3)

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

As printed (Eq. 2)

y wood = β wood1D βwood2 + ewood

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

Stem biomass = 0.0804 * D^2.4041 + 0.0184 * D^2.0703
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
Jack pine bwood1 0.0804
Equation · Table 3, Jack pine
bwood2 2.4041
Equation · Table 3, Jack pine
bbark1 0.0184
Equation · Table 3, Jack pine
bbark2 2.0703
Equation · Table 3, Jack pine
Jack pine 364 18.6±0.5 15.9±0.3 153.6±7.8
Trees measured · Table 2 (No. of trees)
(1.7;41.0) (2.9;27.0) (0.7;784.7)
Smallest DBH · Table 2, Jack pine (ranges of dbh, height, total biomass)
Stem 0.0329 0.92 37.2 3.26 0.0010 0.98 17.6 3.97
R² · Table 5, Jack pine (AdjRSq in the dbh-based set, first block)
Trees measured
364
DBH range
1.7–41 cm
R²
0.92
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Canada: Alberta, Manitoba, Nova Scotia, Northwest Territories, Ontario, Quebec, Saskatchewan (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
117
Stem biomass (kg)
55
Carbon (kg), ×0.47
202
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500600700510152025303540DBH (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 = 20117117Computed from the printed form
computed from the published form at dbh = 20 cm

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