Tree Allometrics

Equations / Height

Height from DBH, modified exponential (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)

Modified Exponential Y = β0 × exp β1 X 38.7760 -16.4933 - 3.393 0.7071 158.85

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

Height = 38.776 * exp(-16.4933 / D)
D
Diameter at breast height (1.3 m), cm

Y = β0·exp(β1/X), with β1 negative as printed; form read from the typeset layout 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
0.7071
Method
Nonlinear/linear regression (CurveExpert/R) on 65 directly measured fallen trees; r2 is the adjusted R² printed in Table 3; Syx = 3.393 m
Where
Maracá Ecological Station (PPBio grid), Roraima, northern Brazilian Amazonia
Last checked
2026-11-02
Calculate
17
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 = 201717Computed from the printed form
hand-computed from the published coefficients in Table 3
D = 4025.725.7Computed from the printed form
hand-computed from the published coefficients in Table 3
D = 7030.630.6Computed from the printed form
hand-computed from the published coefficients in Table 3

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