Tree Allometrics

Ulmus americana / Aboveground biomass

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

Aboveground biomassUlmus americana · UlmaceaeCanadaRead from the original paper
Photo of Ulmus americana
Étienne Lacroix-Carignan · CC0 · iNaturalist
Equation

As printed (Eq. 2)

y wood = β wood1D βwood2 + ewood

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

Aboveground biomass = 0.0402 * D^2.5804 + 0.0073 * D^2.4859 + 0.0401 * D^2.1826 + 0.075 * D^1.3436
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
White elm bwood1 0.0402
Equation · Table 3, White elm
bwood2 2.5804
Equation · Table 3, White elm
bbark1 0.0073
Equation · Table 3, White elm
bbark2 2.4859
Equation · Table 3, White elm
bbranches1 0.0401
Equation · Table 3, White elm
bbranches2 2.1826
Equation · Table 3, White elm
bfoliage1 0.0750
Equation · Table 3, White elm
bfoliage2 1.3436
Equation · Table 3, White elm
White elm 81 20.3±1.1 13.5±0.5 203.5±28.8
Trees measured · Table 2 (No. of trees)
(0.7;55.2) (2.1;23.2) (0.2;1832.2)
Smallest DBH · Table 2, White elm (ranges of dbh, height, total biomass)
Total 0.0377 0.97 43.7 3.28 0.0337 0.97 46.3 3.30
R² · Table 5, White elm (AdjRSq in the dbh-based set, first block)
Trees measured
81
DBH range
0.7–55.2 cm
R²
0.97
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Ontario, Canada (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
136
Aboveground biomass (kg)
63.9
Carbon (kg), ×0.47
234
CO₂e (kg), ×44/12
Fitted DBH range0200400600800510152025303540DBH (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 = 20136136Computed from the printed form
computed from the published form at dbh = 20 cm

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