Tree Allometrics

Equations / Branch biomass

Six Guanajuato oaks pooled, system 2 (wood density, D and H): branch biomass

Branch biomassQuercus (six species: rugosa, obtusata, sideroxyla, coccolobifolia, laurina, candicans) · FagaceaeMexiconaturalRead from the original paper

Fitted on these 6 species: Quercus rugosa, Quercus obtusata, Quercus sideroxyla, Quercus coccolobifolia, Quercus laurina, Quercus candicans

4 of the 6 species it was fitted on · iNaturalist photos, hover for credit
Equation

As printed (Table 5, model 4)

Br = 0.486602 × (ρDn² × At)^0.631701

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

Branch biomass = 0.486602 * (rho * D^2 * H)^0.631701
rho
Wood density (oven-dry mass / green volume), g/cm³
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Dn and At are diameter at breast height and total height (At measured after felling, stump height included). Adjusted R2 (not stored): stem 0.9255, branches 0.7462 (Table 5). Wood density rho is oven-dry mass at 70 °C over green volume per the paper (g cm–3); pooled range 0.60 to 0.83 (Table 1). Foliage and total of this system not added (see source notes).

Source
Un total de 165 árboles
Trees measured · Methods / Table 1
Trees measured
165
DBH range
4.8–48.6 cm
Height range
3.55–20.6 m
Method
Additive system of component equations fitted simultaneously (iterated seemingly unrelated regression)
Where
Sierra de Santa Rosa, Guanajuato (bosques de encino)
Last checked
2026-11-02
Calculate
Height from
58.3
Branch biomass (kg)
27.4
Carbon (kg), ×0.47
100
CO₂e (kg), ×44/12
Fitted DBH range050100150200510152025303540DBH (cm)Branch biomass (kg)Branch 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 = 17.9, H = 8.7, rho = 0.758.358.3Computed from the printed form
computed from the published form (Table 5)
D = 35.5, H = 15.5, rho = 0.8217217Computed from the printed form
computed from the published form (Table 5)

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