Equations / Stem volume
Peat swamp forest, all species, volume from D (model 3)
As printed (Best model, all species, p. 10 (Tabel 3 model 3))
In this library's units, ready to compute (m³)
Stem volume = 0.00042 * D^2.2254D- Diameter at breast height (1.3 m), cm
Volume to a 5 cm top diameter by Smalian's formula on 2 m sections (stem volume, no branches). Diameter was taken at 1.3 m or 20 cm above ground (as printed: 'setinggi dada (1,3 m) atau 20 cm di atas permukaan tanah'); the paper does not say which trees used which. Natural-log form as printed, with no correction factor stated. Fit ranges are those of the model-development subset (70% of the trees, Table 1).
doi:10.20886/jwas.v7i1.5538 · Open access · copy we read
Keseluruhan jenis Diameter 13,4 5,6 29,2 5,3 84
- Trees measured
- 84
- DBH range
- 5.6–29.2 cm
- Height range
- 6–24 m
- R²
- 0.955
- Method
- ordinary least squares, non-linear power form V = a0 D^a1
- Where
- IUPHHK PT Tingang Karya Mandiri peat swamp forest, Central Kalimantan
- Last checked
- 2026-11-02
Shaded: the DBH range the model was fitted on. Other inputs held at the values above.
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 = 8 | 0.043 | 0.043 | Computed from the printed form computed from the published form (coefficients as printed) |
| D = 15 | 0.174 | 0.174 | Computed from the printed form computed from the published form (coefficients as printed) |
| D = 25 | 0.542 | 0.542 | Computed from the printed form computed from the published form (coefficients as printed) |
Related
- Peat swamp forest, Dipterocarpaceae group, volume from D and H (model 7) · same paper · Stem volume
- Peat swamp forest, non-Dipterocarpaceae group, volume from D (model 1) · same paper · Stem volume