Tree Allometrics

Betula populifolia / Branch biomass

Canadian national equation, grey birch, dbh only (branches; Table 3)

Branch biomassBetula populifolia · BetulaceaeCanadaRead from the original paper
Photo of Betula populifolia
© Homer Edward Price · CC BY · iNaturalist
Equation

As printed (Eq. 2)

y branches = β branches1D βbranches2 + e branches

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

Branch biomass = 0.0088 * D^2.5689
D
Diameter at breast height (1.3 m), cm

All branches, cut at the stem base (live branches; dead branches excluded). 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
bbranches1 0.0088
Equation · Table 3, Grey birch
bbranches2 2.5689
Equation · Table 3, Grey birch
Grey birch 43 10.3±0.8 8.9±0.5 39.8±6.9
Trees measured · Table 2 (No. of trees)
(2.2;22.7) (2.3;14.9) (0.6;181.0)
Smallest DBH · Table 2, Grey birch (ranges of dbh, height, total biomass)
Branches 0.0002 0.76 4.2 4.10 0.0005 0.69 4.7 3.69
R² · Table 5, Grey birch (AdjRSq in the dbh-based set, first block)
Trees measured
43
DBH range
2.2–22.7 cm
R²
0.76
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Nova Scotia, Canada (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
19.4
Branch biomass (kg)
9.09
Carbon (kg), ×0.47
33.3
CO₂e (kg), ×44/12
Fitted DBH range020406080100120510152025303540DBH (cm)Branch biomass (kg)Branch 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 = 2019.419.4Computed from the printed form
computed from the published form at dbh = 20 cm

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