Tree Allometrics

Equations / Height

Height from DBH, logistic power (Table 3)

HeightMixed tree species of ombrophilous/seasonal forest ecotone (65 fallen trees)BrazilnaturalRead from the original paper
Many species, no single photo
Equation

As printed (Table 3)

Logistic Power Y = β0 / 1 + (X / β1) β2 43.6264 29.7079 -1.0709 3.372 0.7152 159.16

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

Height = 43.6264 / (1 + (D / 29.7079)^(-1.0709))
D
Diameter at breast height (1.3 m), cm

Y = β0 / (1 + (X/β1)^β2) with β2 negative as printed; form read from the typeset Table 2/3 layout (stacked fraction, exponent on (X/β1)) and sanity-checked against Table S1 trees. Stem diameter was measured at 1.30 m, or 0.5 m above buttresses, on recently fallen trees (live or dead). The paper reports no maximum DBH in the text (see Table S1), so dbh_max is left out. Table 3 ranks five models; this is one of the four with fully legible coefficients (the Modified Hoerl row, with b1 = 0.000035, was not used).

Source
A total of 65 individual trees were sampled
Trees measured · Material and Methods, Sampling design
with stem diameter ≥10 cm
Smallest DBH · Material and Methods, Sampling design
(mean ± CI 0.05 = 24.1 ± 1.5 m; range = 11.7 - 37.7 m)
h min m · Results, paragraph on Figure 3
R² adj
R² · Table 3 column header
Trees measured
65
DBH range
from 10 cm
Height range
11.7–37.7 m
R²
0.7152
Method
Nonlinear/linear regression (CurveExpert/R) on 65 directly measured fallen trees; r2 is the adjusted R² printed in Table 3; Syx = 3.372 m
Where
Maracá Ecological Station (PPBio grid), Roraima, northern Brazilian Amazonia
Last checked
2026-11-02
Calculate
17.3
Height (m)
Fitted DBH range051015202530510152025303540DBH (cm)Height (m)Height

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 = 2017.317.3Computed from the printed form
hand-computed from the published coefficients in Table 3
D = 4025.325.3Computed from the printed form
hand-computed from the published coefficients in Table 3
D = 7031.231.2Computed from the printed form
hand-computed from the published coefficients in Table 3

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