Tree Allometrics

Sophora tetraptera / Height

Sophora tetraptera, NZ, height from RCD (Table 3)

HeightSophora tetraptera · FabaceaeNew ZealandplantationRead from the original paper
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Equation

As printed (Table 3, Height, Sophora tetraptera)

y = 0.529ln(x)

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

Height = 0.529 * ln(10 * DRC)
DRC
Root collar / stem base diameter, cm

Open-spaced juvenile plants (2-year-old containerised plants on-grown for 3 years, sampled up to 5 years). The tables are headed 'at age 5 years' but the appendix figures show points from all harvest years, and the paper gives no n or RCD range for these fits, so none is recorded. x is root collar diameter in mm; biomass in g and height in m (units inferred from Table 2 and Appendix 1 means, which the equations reproduce; the paper does not print units beside the equations).

Source
0.921
R² · Table 3, Height, Sophora tetraptera, r² column
R²
0.921
Method
ordinary least squares, natural log-linear through origin (y = m ln x)
Where
Taruheru River terrace, Gisborne, New Zealand
Last checked
2026-11-02
Calculate
1.58
Height (m)
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
DRC = 21.581.58Computed from the printed form
hand-computed from the published form (RCD in mm, mass in g, converted)
DRC = 62.172.17Computed from the printed form
hand-computed from the published form (RCD in mm, mass in g, converted)
DRC = 152.652.65Computed from the printed form
hand-computed from the published form (RCD in mm, mass in g, converted)

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