Tree Allometrics

Picea glauca / Stem biomass

Canadian national equation, white spruce, dbh and height (stem wood plus stem bark; Table 4)

Stem biomassPicea glauca · PinaceaeCanadaRead from the original paper
Photo of Picea glauca
© Douglas Goldman · CC BY-SA · iNaturalist
Equation

As printed (Eq. 3)

y wood = β wood1D βwood2Hβwood3 + ewood

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

Stem biomass = 0.0265 * D^1.7952 * H^0.9733 + 0.0124 * D^1.6962 * H^0.6489
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

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 βbark2Hβbark3 + e bark
Equation · Eq. 3
White spruce bwood1 0.0265
Equation · Table 4, White spruce
bwood2 1.7952
Equation · Table 4, White spruce
bwood3 0.9733
Equation · Table 4, White spruce
bbark1 0.0124
Equation · Table 4, White spruce
bbark2 1.6962
Equation · Table 4, White spruce
bbark3 0.6489
Equation · Table 4, White spruce
White spruce 832 16.6±0.3 12.9±0.2 123.6±5.7
Trees measured · Table 2 (No. of trees)
(1.8;51.9) (1.1;37.5) (0.4;1344.6)
Smallest DBH · Table 2, White spruce (ranges of dbh, height, total biomass)
Stem 0.0003 0.94 35.2 4.81 0.0004 0.98 18.7 4.19
R² · Table 5, White spruce (AdjRSq in the dbh- and height-based set, second block)
Trees measured
832
DBH range
1.8–51.9 cm
Height range
1.1–37.5 m
R²
0.98
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Canada: Alberta, Manitoba, Newfoundland and Labrador, Nova Scotia, Northwest Territories, Ontario, Quebec, Saskatchewan, Yukon (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
Height from
91.7
Stem biomass (kg)
43.1
Carbon (kg), ×0.47
158
CO₂e (kg), ×44/12
Fitted DBH range050100150200250300350510152025303540DBH (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 = 20, H = 1591.791.7Computed from the printed form
computed from the published form at dbh = 20 cm, H = 15 m

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