Tree Allometrics

Thuja occidentalis / Aboveground biomass

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

Aboveground biomassThuja occidentalis · CupressaceaeCanadaRead from the original paper
Photo of Thuja occidentalis
© 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)

Aboveground biomass = 0.0295 * D^1.7026 * H^0.9428 + 0.0076 * D^1.7861 * H^0.6132 + 0.0501 * D^2.5165 * H^(-0.8774) + 0.0813 * D^2.218 * H^(-0.7907)
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). 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
Eastern white-cedar bwood1 0.0295
Equation · Table 4, Eastern white-cedar
bwood2 1.7026
Equation · Table 4, Eastern white-cedar
bwood3 0.9428
Equation · Table 4, Eastern white-cedar
bbark1 0.0076
Equation · Table 4, Eastern white-cedar
bbark2 1.7861
Equation · Table 4, Eastern white-cedar
bbark3 0.6132
Equation · Table 4, Eastern white-cedar
bbranches1 0.0501
Equation · Table 4, Eastern white-cedar
bbranches2 2.5165
Equation · Table 4, Eastern white-cedar
bbranches3 –0.8774
Equation · Table 4, Eastern white-cedar
bfoliage1 0.0813
Equation · Table 4, Eastern white-cedar
bfoliage2 2.2180
Equation · Table 4, Eastern white-cedar
bfoliage3 –0.7907
Equation · Table 4, Eastern white-cedar
Eastern white-cedar 184 20.8±0.9 11.8±0.3 117.2±9.3
Trees measured · Table 2 (No. of trees)
(2.1;66.2) (1.9;21.9) (1.0;917.4)
Smallest DBH · Table 2, Eastern white-cedar (ranges of dbh, height, total biomass)
Total 0.0315 0.95 29.5 2.96 0.0140 0.96 26.6 3.15
R² · Table 5, Eastern white-cedar (AdjRSq in the dbh- and height-based set, second block)
Trees measured
184
DBH range
2.1–66.2 cm
Height range
1.9–21.9 m
R²
0.96
Method
Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
Where
Ontario and Quebec, Canada (ENFOR archival data, early 1980s)
Last checked
2026-11-03
Calculate
Height from
86.7
Aboveground biomass (kg)
40.8
Carbon (kg), ×0.47
149
CO₂e (kg), ×44/12
Fitted DBH range050100150200250300350510152025303540DBH (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 = 1586.786.7Computed 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