Equations / Height
Height from DBH, Quadratic model, várzea
As printed (Table 1 (form) and Table 2, Várzea block)
In this library's units, ready to compute (m)
Height = exp(0.51504 + 1.07489 * ln(D) - 0.10005 * ln(D)^2)D- Diameter at breast height (1.3 m), cm
Predicts total tree height from DBH. The quadratic form is read as a + b ln(DBH) + c (ln DBH)^2 inside exp(); Table 1 prints ln(DBH) with a superscript 2, and ln(DBH^2) would not be separable from the b term. RSE printed in Table 2 is 4.161 (height scale, m), so fit.rse is not stored. Ranges are those printed for the trees sampled in this forest type. No correction factor is applied; the paper reports local models deviate 0.1% from measured heights.
doi:10.7717/peerj.18974 · Open access · copy we read
We sampled 1,156 trees of 367 species ... in the terra-firme sites, and 806 trees of 65 species ... in várzea
In the terra-firme sites, trees ranged from 1 to 109.1 cm DBH and 1.2 to 51.9 m in total height. In várzea sites, trees ranged from 5 to 139.5 cm DBH and 2.3 to 38.8 m in total height.
Adj. pseudo R2 0.65
- Trees measured
- 806
- DBH range
- 5–139.5 cm
- Height range
- 2.3–38.8 m
- R²
- 0.65
- Method
- nonlinear least squares height-diameter model; R2 is the adjusted pseudo R2
- Where
- Seasonally flooded várzea forest, Mazagão, Amapá, Brazil
- 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 = 10 | 11.7 | 11.7 | Computed from the printed form computed from the published form (coefficients as printed) |
| D = 30 | 20.4 | 20.4 | Computed from the printed form computed from the published form (coefficients as printed) |
| D = 60 | 25.5 | 25.5 | Computed from the printed form computed from the published form (coefficients as printed) |
Related
- Height from DBH, Michaelis-Menten model, both forests pooled · Baia et al. 2025 · DBH
- Height from DBH, Quadratic model, both forests pooled · Baia et al. 2025 · DBH
- Height from DBH, Weibull model, both forests pooled · Baia et al. 2025 · DBH
- Height from DBH, Michaelis-Menten model, terra-firme · Baia et al. 2025 · DBH
- Height from DBH, Quadratic model, terra-firme · Baia et al. 2025 · DBH
- Height from DBH, Michaelis-Menten model, várzea · Baia et al. 2025 · DBH
- Height from DBH, Michaelis-Menten model, both forests pooled · same paper · Height
- Height from DBH, Quadratic model, both forests pooled · same paper · Height
- Height from DBH, Weibull model, both forests pooled · same paper · Height
- Height from DBH, Michaelis-Menten model, terra-firme · same paper · Height
- Height from DBH, Quadratic model, terra-firme · same paper · Height
- Height from DBH, Michaelis-Menten model, várzea · same paper · Height