Tree Allometrics

Picea rubens / Aboveground biomass

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

Aboveground biomassPicea rubens · PinaceaeCanadaRead from the original paper
Photo of Picea rubens
© 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)

Aboveground biomass = 0.0989 * D^2.2814 + 0.022 * D^2.0908 + 0.0005 * D^3.275 + 0.0066 * D^2.4213
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
Red spruce bwood1 0.0989
Equation · Table 3, Red spruce
bwood2 2.2814
Equation · Table 3, Red spruce
bbark1 0.0220
Equation · Table 3, Red spruce
bbark2 2.0908
Equation · Table 3, Red spruce
bbranches1 0.0005
Equation · Table 3, Red spruce
bbranches2 3.2750
Equation · Table 3, Red spruce
bfoliage1 0.0066
Equation · Table 3, Red spruce
bfoliage2 2.4213
Equation · Table 3, Red spruce
Red spruce 55 22.9±1.2 15.9±0.4 207.7±22.4
Trees measured · Table 2 (No. of trees)
(6.5;43.5) (8.0;21.2) (9.1;811.7)
Smallest DBH · Table 2, Red spruce (ranges of dbh, height, total biomass)
Total 0.0059 0.97 29.1 3.64 0.0196 0.98 25.9 3.12
R² · Table 5, Red spruce (AdjRSq in the dbh-based set, first block)
Trees measured
55
DBH range
6.5–43.5 cm
R²
0.97
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Quebec, Canada (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
122
Aboveground biomass (kg)
57.3
Carbon (kg), ×0.47
210
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 = 20122122Computed from the printed form
computed from the published form at dbh = 20 cm

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