Equations / Stem volume
Rubber (PR107) stem volume from D and H (Eq. 9, Schumacher-Hall)
Stem volumeHevea brasiliensis (clone PR107) · EuphorbiaceaeCambodiaplantationRead from the original paper
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Equation
As printed (Eqs. 8-9, p. 338)
log V = -3.73563 + 2.23961 log D + 0.15334 log H (R2 = 0.9245, N = 60), or V = 0.00018381 D^2.23961 H^0.15334
In this library's units, ready to compute (m³)
Stem volume = 0.00018381 * D^2.23961 * H^0.15334D- Diameter at breast height (1.3 m), cm
H- Total tree height, m
Volume is over-bark stem volume of 60 felled PR107 trees (1 m sections, Smalian). Logs are base 10: 10^-3.6041 = 0.00024884 and 10^-3.73563 = 0.00018381 as printed. R2 is of the log-log regression. Ranges follow the text on p. 338; Table 1 (p. 337) prints per-stand minima/maxima whose overall span is DBH 26.0-62.0 cm and height 16.2-47.3 m, which does not match the text exactly.
Source
doi:10.20659/jfp.13.2_335 · Open access · copy we read
R2 = 0.9245, N = 60
The range of data is 20-62cm for DBH, 16.7-47.0m for total height, and 0.25 to 3.41m³ for stem volume.
- Trees measured
- 60
- DBH range
- 20–62 cm
- Height range
- 16.7–47 m
- R²
- 0.9245
- Method
- log-log linear regression (log10) of over-bark stem volume on D (and H), 60 felled trees, ages 36-46 years
- Where
- Krek Rubber Plantation, Kompong Cham Province
- Last checked
- 2026-11-02
Calculate
Height from
0.623
Stem volume (m³)
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%.
| Inputs | Expected | We get | From |
|---|---|---|---|
| D = 30, H = 28 | 0.623 | 0.623 | Computed from the printed form computed from the published form (coefficients as printed) |
| D = 45, H = 32 | 1.58 | 1.58 | Computed from the printed form computed from the published form (coefficients as printed) |
Related
- Rubber (PR107) stem volume from D (Eq. 7) · Khun et al. 2008 · DBH
- Rubber (PR107) stem volume from D (Eq. 7) · same paper · Stem volume