Tree Allometrics

Equations / Aboveground biomass

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

Aboveground biomassCarya · JuglandaceaeCanadaRead from the original paper
Covers the whole genus
Equation

As printed (Eq. 3)

y wood = β wood1D βwood2Hβwood3 + ewood

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

Aboveground biomass = 0.0139 * D^1.5913 * H^1.508 + 0.0081 * D^1.4943 * H^1.1324 + 0.005 * D^3.0463 + 0.0121 * D^2.0865
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 branches, foliage term: the paper leaves its height exponent blank (—, not significantly different from zero). The paper names this taxon only as 'Hickory' (Carya Nutt.), so it is a genus record. 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
Hickory bwood1 0.0139
Equation · Table 4, Hickory
bwood2 1.5913
Equation · Table 4, Hickory
bwood3 1.5080
Equation · Table 4, Hickory
bbark1 0.0081
Equation · Table 4, Hickory
bbark2 1.4943
Equation · Table 4, Hickory
bbark3 1.1324
Equation · Table 4, Hickory
bbranches1 0.0050
Equation · Table 4, Hickory
bbranches2 3.0463
Equation · Table 4, Hickory
bbranches3 —
Equation · Table 4, Hickory
bfoliage1 0.0121
Equation · Table 4, Hickory
bfoliage2 2.0865
Equation · Table 4, Hickory
bfoliage3 —
Equation · Table 4, Hickory
Hickory 76 20.8±1.2 19.3±0.8 363.3±42.4
Trees measured · Table 2 (No. of trees)
(2.8;46.6) (3.9;29.4) (1.4;1335.1)
Smallest DBH · Table 2, Hickory (ranges of dbh, height, total biomass)
Total 1.2935 0.87 131.6 2.76 0.0195 0.95 83.9 3.79
R² · Table 5, Hickory (AdjRSq in the dbh- and height-based set, second block)
Hickory Caryer Carya Nutt.
Taxon · Appendix B, Table B1
Trees measured
76
DBH range
2.8–46.6 cm
Height range
3.9–29.4 m
R²
0.95
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
165
Aboveground biomass (kg)
77.3
Carbon (kg), ×0.47
284
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500600700800510152025303540DBH (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 = 15165165Computed from the printed form
computed from the published form at dbh = 20 cm, H = 15 m

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