Tree Allometrics

Abies lasiocarpa / Aboveground biomass

Canadian national equation, alpine fir, dbh only (sum of wood, bark, branches, foliage; Table 3)

Aboveground biomassAbies lasiocarpa · PinaceaeCanadaRead from the original paper
Photo of Abies lasiocarpa
© Kaden Slone · CC BY · iNaturalist
Equation

As printed (Eq. 2)

y wood = β wood1D βwood2 + ewood

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

Aboveground biomass = 0.0528 * D^2.4309 + 0.0108 * D^2.3876 + 0.0121 * D^2.3519 + 0.0251 * D^2.0389
D
Diameter at breast height (1.3 m), cm

Total aboveground biomass = wood + bark + branches + foliage, each fitted as its own equation; the total is their sum (additivity by construction). 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
y branches = β branches1D βbranches2 + e branches
Equation · Eq. 2
y foliage = β foliage1D βfoliage2 + efoliage
Equation · Eq. 2
Alpine fir bwood1 0.0528
Equation · Table 3, Alpine fir
bwood2 2.4309
Equation · Table 3, Alpine fir
bbark1 0.0108
Equation · Table 3, Alpine fir
bbark2 2.3876
Equation · Table 3, Alpine fir
bbranches1 0.0121
Equation · Table 3, Alpine fir
bbranches2 2.3519
Equation · Table 3, Alpine fir
bfoliage1 0.0251
Equation · Table 3, Alpine fir
bfoliage2 2.0389
Equation · Table 3, Alpine fir
Alpine fir 60 19.6±1.3 14.8±0.8 158.4±19.5
Trees measured · Table 2 (No. of trees)
(2.1;36.5) (2.2;23.7) (1.7;461.8)
Smallest DBH · Table 2, Alpine fir (ranges of dbh, height, total biomass)
Total 0.2380 0.96 30.8 2.44 0.0313 0.97 26.7 3.00
R² · Table 5, Alpine fir (AdjRSq in the dbh-based set, first block)
Trees measured
60
DBH range
2.1–36.5 cm
R²
0.96
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Alberta, Canada (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
116
Aboveground biomass (kg)
54.4
Carbon (kg), ×0.47
199
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500600700510152025303540DBH (cm)Aboveground biomass (kg)Aboveground 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 = 20116116Computed from the printed form
computed from the published form at dbh = 20 cm

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