Tree Allometrics

Equations / Height

Shorea assamica height from D, Linear model (Table 4)

HeightShorea assamica · DipterocarpaceaeIndonesianaturalRead from the original paper
No openly licensed photo yet
Equation

As printed (Table 1 and Table 4, Linear row)

Linear H = a + b.DBH; a = 6.97, b = 0.23

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

Height = 6.97 + 0.23 * D
D
Diameter at breast height (1.3 m), cm

Fitted on the 70% model-development subset (1009 trees); DBH and height ranges are that subset (Table 3). Only trees with DBH >= 20 cm were recorded. Coefficients are printed to two decimals. The paper also lists Exponential and Gompertz models (Table 4) that were not added: the Exponential b is printed as 0.01 (too coarse to reproduce the fit) and the Gompertz coefficients as printed (a=152.37, b=0.01, c=170.49) do not give a sensible curve.

Source
1009 tree height and diameter datasets were utilized
Trees measured · Section 3.1
R2 0.72
R² · Table 4
Trees measured
1,009
DBH range
20–67 cm
Height range
11–28 m
R²
0.72
Method
nonlinear least squares height-diameter model, fitted on 1009 of 1440 trees
Where
Tabalong District, South Kalimantan (PT Aya Yayang Indonesia concession, secondary lowland dipterocarp forest)
Last checked
2026-11-02
Calculate
12.72
Height (m)
Fitted DBH range051015201020304050DBH (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 = 2512.712.7Computed from the printed form
computed from the published form (coefficients as printed)
D = 4016.216.2Computed from the printed form
computed from the published form (coefficients as printed)
D = 6020.820.8Computed from the printed form
computed from the published form (coefficients as printed)

Report a problem with this equation · JSON

Related

Compare these curves