Tree Allometrics

Piscidia piscipula / Aboveground biomass

Piscidia piscipula, additive system S2 (D²H, Eq. 7-10): total aboveground biomass (sum of components)

Aboveground biomassPiscidia piscipula (L.) Sarg. · FabaceaeMexiconaturalRead from the original paper
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Equation

As printed (Eq. 10)

Bt = Σ e^[−βi0+βi1 ln(Dn² AT)] + ε4 (10)

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

Aboveground biomass = (exp(-3.45213 + 0.943879 * ln(D^2 * H))) + (exp(-4.00219 + 0.950832 * ln(D^2 * H))) + (exp(-5.14483 + 0.790513 * ln(D^2 * H)))
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

The paper prints the intercept as a positive estimate and the model with a minus sign in front of it (e^[−β0 + ...]); applied that way. Adjusted R2 (not stored): stem 0.9821, branches 0.9769, twigs with leaves 0.8419, total 0.9931 (Table 3). Dn and AT are the paper's diameter at breast height and total height. Total is the sum of the component equations, as the paper defines it.

Source
Bf = e^[−β10+β11 ln(Dn² AT)] + ε1 (7); Table 2, S2 Fuste: β10 3.45213, β11 0.943879
Equation · Eq. 7, Table 2 (S2)
Br = e^[−β20+β21 ln(Dn² AT)] + ε2 (8); Table 2, S2 Ramas: β20 4.00219, β21 0.950832
Equation · Eq. 8, Table 2 (S2)
Brh = e^[−β30+β31 ln(Dn² AT)] + ε3 (9); Table 2, S2 Ramillas con hojas: β30 5.14483, β31 0.790513
Equation · Eq. 9, Table 2 (S2)
destructivo de 17 individuos
Trees measured · Resumen / Table 1
Trees measured
17
DBH range
5.7–55 cm
Height range
8.12–21 m
Method
Additive nonlinear system of component equations fitted simultaneously by generalized method of moments (GMM)
Where
Escárcega, Campeche (selva mediana subperennifolia)
Last checked
2026-11-02
Calculate
Height from
165
Aboveground biomass (kg)
77.3
Carbon (kg), ×0.47
284
CO₂e (kg), ×44/12
Fitted DBH range0100200300400500600700510152025303540DBH (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 = 20.5, H = 12165165Computed from the printed form
computed from the published form (Table 2 coefficients, intercept with the printed minus sign)
D = 40.2, H = 17.1817817Computed from the printed form
computed from the published form (Table 2 coefficients, intercept with the printed minus sign)

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