Tree Allometrics

Ulmus americana / Aboveground biomass

Canadian national equation, white elm, dbh and height (sum of wood, bark, branches, foliage; Table 4)

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

As printed (Eq. 3)

y wood = β wood1D βwood2Hβwood3 + ewood

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

Aboveground biomass = 0.0207 * D^2.2276 * H^0.6488 + 0.0078 * D^2.454 + 0.0393 * D^2.188 + 0.0516 * D^1.4511
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Total aboveground biomass = wood + bark + branches + foliage, each fitted as its own equation; the total is their sum (additivity by construction). Height drops out of the bark, branches, foliage term: the paper leaves its height exponent blank (—, not significantly different from zero). 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
y branches = β branches1D βbranches2Hβbranches3 + e branches
Equation · Eq. 3
y foliage = β foliage1D βfoliage2Hβfoliage3 + efoliage
Equation · Eq. 3
White elm bwood1 0.0207
Equation · Table 4, White elm
bwood2 2.2276
Equation · Table 4, White elm
bwood3 0.6488
Equation · Table 4, White elm
bbark1 0.0078
Equation · Table 4, White elm
bbark2 2.4540
Equation · Table 4, White elm
bbark3 —
Equation · Table 4, White elm
bbranches1 0.0393
Equation · Table 4, White elm
bbranches2 2.1880
Equation · Table 4, White elm
bbranches3 —
Equation · Table 4, White elm
bfoliage1 0.0516
Equation · Table 4, White elm
bfoliage2 1.4511
Equation · Table 4, White elm
bfoliage3 —
Equation · Table 4, 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- and height-based set, second block)
Trees measured
81
DBH range
0.7–55.2 cm
Height range
2.1–23.2 m
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
Height from
139
Aboveground biomass (kg)
65.2
Carbon (kg), ×0.47
239
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 = 20, H = 15139139Computed from the printed form
computed from the published form at dbh = 20 cm, H = 15 m

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