Equations / Aboveground biomass
Dry tropical zone AGB from DBH (Eq. 3.2.1)
As printed (Eq. 3.2.1, Section 3.2.1 table)
In this library's units, ready to compute (kg)
Aboveground biomass = exp(-1.996 + 2.32 * ln(D))D- Diameter at breast height (1.3 m), cm
Revised from Brown et al. (1989) for dry forest in India. The primer recommends it for dry zones with rainfall > 900 mm/yr (Eq. 3.2.2, Martinez-Yrizar et al. 1992, for < 900 mm/yr). r2 is the adjusted r² printed in the table. The primer does not say whether a log back-transform correction is included; none applied. Climatic zones per the primer: dry <1500 mm/yr rain with a dry season of several months; moist 1500–4000 mm/yr; wet >4000 mm/yr, lowland conditions only.
https://www.fao.org/4/w4095e/w4095e00.htm · Open access · copy we read
Y= biomass per tree in kg, D = dbh in cm, and BA = basal area in cm2
5-40 | 28 | 0.89
- Trees measured
- 28
- DBH range
- 5–40 cm
- R²
- 0.89
- Where
- Tropics, dry zone
- Last checked
- 2026-11-01
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 = 20 | 141.8 | 141.8 | Computed from the printed form computed with python3 from the published form |
Related
- Moist tropical zone AGB, power law (Eq. 3.2.4) · Brown 1997 · DBH
- Moist tropical zone AGB, quadratic (Eq. 3.2.3) · Brown 1997 · DBH
- Wet tropical zone AGB, quadratic (Brown 1997 Eq. 3.2.5) · Brown & Iverson 1992 · DBH
- Moist tropical zone AGB, power law (Eq. 3.2.4) · same paper · Aboveground biomass
- Moist tropical zone AGB, quadratic (Eq. 3.2.3) · same paper · Aboveground biomass
- Tropical pines AGB from DBH (Eq. 3.1.8 / 3.2.8) · same paper · Aboveground biomass