Tree Allometrics

Equations / Aboveground biomass

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

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

As printed (Eq. 2)

y wood = β wood1D βwood2 + ewood

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

Aboveground biomass = 0.2116 * D^2.2013 + 0.0365 * D^2.1133 + 0.0087 * D^2.8927 + 0.0173 * D^1.983
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). 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 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
Hickory bwood1 0.2116
Equation · Table 3, Hickory
bwood2 2.2013
Equation · Table 3, Hickory
bbark1 0.0365
Equation · Table 3, Hickory
bbark2 2.1133
Equation · Table 3, Hickory
bbranches1 0.0087
Equation · Table 3, Hickory
bbranches2 2.8927
Equation · Table 3, Hickory
bfoliage1 0.0173
Equation · Table 3, Hickory
bfoliage2 1.9830
Equation · Table 3, 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-based set, first block)
Hickory Caryer Carya Nutt.
Taxon · Appendix B, Table B1
Trees measured
76
DBH range
2.8–46.6 cm
R²
0.87
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
232
Aboveground biomass (kg)
109
Carbon (kg), ×0.47
400
CO₂e (kg), ×44/12
Fitted DBH range02004006008001,0001,2001,400510152025303540DBH (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 = 20232232Computed from the printed form
computed from the published form at dbh = 20 cm

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