Tree Allometrics

Betula alleghaniensis / Stem biomass

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

Stem biomassBetula alleghaniensis · BetulaceaeCanadaRead from the original paper
Photo of Betula alleghaniensis
© 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 = 0.0259 * D^1.9044 * H^0.9715 + 0.0069 * D^2.0834 * H^0.5371
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
Yellow birch bwood1 0.0259
Equation · Table 4, Yellow birch
bwood2 1.9044
Equation · Table 4, Yellow birch
bwood3 0.9715
Equation · Table 4, Yellow birch
bbark1 0.0069
Equation · Table 4, Yellow birch
bbark2 2.0834
Equation · Table 4, Yellow birch
bbark3 0.5371
Equation · Table 4, Yellow birch
Yellow birch 280 25.7±0.9 16.4±0.3 494.4±34.4
Trees measured · Table 2 (No. of trees)
(0.8;70.3) (2.7;25.6) (0.1;2951.4)
Smallest DBH · Table 2, Yellow birch (ranges of dbh, height, total biomass)
Stem 4.5487 0.94 95.5 2.03 0.7738 0.95 88.6 2.44
R² · Table 5, Yellow birch (AdjRSq in the dbh- and height-based set, second block)
Trees measured
280
DBH range
0.8–70.3 cm
Height range
2.7–25.6 m
R²
0.95
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Canada: Newfoundland and Labrador, Ontario, Quebec (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
Height from
123
Stem biomass (kg)
57.9
Carbon (kg), ×0.47
212
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500510152025303540DBH (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 = 15123123Computed from the printed form
computed from the published form at dbh = 20 cm, H = 15 m

Report a problem with this equation · JSON

Related

Compare these curves