Ulmus americana / Stem biomass

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

Stem biomassUlmus americana · UlmaceaeCanadaRead from the original paper

Equation

As printed (Eq. 3)

y wood = β wood1D βwood2Hβwood3 + ewood

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

Stem biomass = 0.0207 * D^2.2276 * H^0.6488 + 0.0078 * D^2.454

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. Height drops out of the bark 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

Lambert, M.-C., Ung, C.-H., Raulier, F. (2005). Canadian national tree aboveground biomass equations. Canadian Journal of Forest Research, 35(8), 1996–2018.

doi:10.1139/x05-112 · Paywalled · copy we read

y bark = β bark1D βbark2Hβbark3 + e bark

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

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)

Stem 0.0265 0.97 36.3 3.27 0.0199 0.97 39.0 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

DBH (cm)Height (m)

Height from

107

Stem biomass (kg)

50.3

Carbon (kg), ×0.47

184

CO₂e (kg), ×44/12

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%.

Inputs	Expected	We get	From
D = 20, H = 15	107	107	Computed from the printed form computed from the published form at dbh = 20 cm, H = 15 m

Report a problem with this equation · JSON

Canadian national equation, white elm, dbh only (stem wood plus stem bark; Table 3) · Lambert et al. 2005 · DBH
Canadian national equation, alpine fir, dbh only (branches; Table 3) · same paper · Branch biomass
Canadian national equation, alpine fir, dbh and height (branches; Table 4) · same paper · Branch biomass
Canadian national equation, alpine fir, dbh and height (foliage; Table 4) · same paper · Foliage biomass
Canadian national equation, alpine fir, dbh and height (stem wood plus stem bark; Table 4) · same paper · Stem biomass
Canadian national equation, alpine fir, dbh and height (sum of wood, bark, branches, foliage; Table 4) · same paper · Aboveground biomass
Canadian national equation, alpine fir, dbh only (foliage; Table 3) · same paper · Foliage biomass
Canadian national equation, alpine fir, dbh only (stem wood plus stem bark; Table 3) · same paper · Stem biomass
Canadian national equation, alpine fir, dbh only (sum of wood, bark, branches, foliage; Table 3) · same paper · Aboveground biomass

Compare these curves

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

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