Tree Allometrics

Pinus contorta / Stem biomass

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

Stem biomassPinus contorta var. latifolia · PinaceaeCanadaRead from the original paper
Photo of Pinus contorta var. latifolia
© Alison Northup · CC BY · iNaturalist
Equation

As printed (Eq. 2)

y wood = β wood1D βwood2 + ewood

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

Stem biomass = 0.0475 * D^2.5437 + 0.0186 * D^2.0807
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
Lodgepole pine bwood1 0.0475
Equation · Table 3, Lodgepole pine
bwood2 2.5437
Equation · Table 3, Lodgepole pine
bbark1 0.0186
Equation · Table 3, Lodgepole pine
bbark2 2.0807
Equation · Table 3, Lodgepole pine
Lodgepole pine 201 15.0±0.6 12.7±0.4 99.0±8.8
Trees measured · Table 2 (No. of trees)
(2.5;39.0) (2.5;25.9) (0.8;694.4)
Smallest DBH · Table 2, Lodgepole pine (ranges of dbh, height, total biomass)
Stem 0.0250 0.96 21.0 3.18 0.0004 0.99 11.6 4.13
R² · Table 5, Lodgepole pine (AdjRSq in the dbh-based set, first block)
Lodgepole pine Pin lodgepole Pinus contorta var. latifolia Engelm.
Taxon · Appendix B, Table B1
Trees measured
201
DBH range
2.5–39 cm
R²
0.96
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Alberta and Yukon, Canada (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
106
Stem biomass (kg)
50
Carbon (kg), ×0.47
183
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 = 20106106Computed from the printed form
computed from the published form at dbh = 20 cm

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