Tree Allometrics

Hymenolobium petraeum / Stem volume

Commercial stem volume from DBH, Hymenolobium petraeum (species-specific, Table 2)

Stem volumeHymenolobium petraeum · FabaceaeBrazilnaturalRead from the original paper
No openly licensed photo yet
Equation

As printed (Table 2, SSEs rows)

H. petraeum vc = exp(-7.22502 + 2.09783ln(DBH)) 0.61 5.567 36.4

In this library's units, ready to compute (m³)

Stem volume = exp(-7.22502 + 2.09783 * ln(D))
D
Diameter at breast height (1.3 m), cm

Species-specific equation (H. petraeum, Angelim pedra). vc is the commercial volume of the stem (sum of Smalian log volumes, hollows discounted), not total tree volume. No back-transformation correction factor is stated, so none is applied. n_trees is the adjustment (fitting) set; DBH range is that of the whole dataset (all species), not stated per species. Ten percent of trees were held out for validation. 8 of the 36+1 species equations in Table 2 were added (the ten most important commercial species by harvested volume plus H. petraeum); the generic FMA equation was rejected by the authors' own paired t-test. One of the species with very large trees; the paper notes generic equations underestimated its volume by 15.7-16.6% versus 4.4% for this equation.

Source
Hymenolobium petraeum Ducke Angelim pedra 247 27
Trees measured · Table 1 (columns: adjustment, validation)
29,119 trees (50.0 cm ≤ DBH ≤ 175.0 cm) of 43 commercial species
Smallest DBH · Material and Methods, Data collection
composed the commercial volume (vc) of the stem
Output · Material and Methods, Data collection
Trees measured
247
DBH range
from 50 cm
R²
0.61
Method
Model 2 (Husch) fitted by least squares on ln(vc); r2 is the adjusted R² recalculated in arithmetic units; Syx = 5.567 m3 (36.4%)
Where
Tapajós National Forest, Pará (community forest management concession), eastern Brazilian Amazon
Last checked
2026-11-02
Calculate
3.91
Stem volume (m³)
Fitted DBH range0510152020406080100120DBH (cm)Stem volume (m³)Stem volume

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 = 603.913.91Computed from the printed form
hand-computed from the Table 2 coefficients
D = 909.169.16Computed from the printed form
hand-computed from the Table 2 coefficients
D = 13019.819.8Computed from the printed form
hand-computed from the Table 2 coefficients

Report a problem with this equation · JSON

Related