Equations / Stem biomass
Stem biomass from d2h and wood density (M8)
Stem biomassSeven dominant species of Chilimo forest (Juniperus procera, Podocarpus falcatus, Olea africana, Allophylus abyssinicus, Olinia rochetiana, Rhus glutinosa, Scolopia theifolia)EthiopianaturalRead from the original paper
Many species, no single photo
Equation
As printed (Table 1 and Table 6)
M8 ln(b) = ln(β0) + β1 ln(d^2 h) + β2 ln(ρ) + ε ... -3.127 0.929 0.278*
In this library's units, ready to compute (kg)
Stem biomass = 1.001 * (exp(-3.127 + 0.929 * ln(D^2 * H) + 0.278 * ln(rho)))D- Diameter at breast height (1.3 m), cm
H- Total tree height, m
rho- Wood density (oven-dry mass / green volume), g/cm³
Stem biomass only (branches and leaves not measured), computed as stem volume times basic wood density of each species, so dry mass. Range in fit is for the 194 sampled trees (Section 3.1). The wood density coefficient (0.278) is marked non-significant at alpha = 0.05 in Table 6. Back-transform CF 1.001 from Table S4 applied in expression.
Source
doi:10.4236/ojf.2022.123015 · Open access · copy we read
A total of 193 sampled trees from seven dominant tree species were used to develop the equations.
The diameter, total height, and wood density ranged between 6.2 and 85.0 cm, 5.6 and 27.4 m
CF 1.001
- Trees measured
- 193
- DBH range
- 6.2–85 cm
- Height range
- 5.6–27.4 m
- Correction factor
- 1.001 (applied)
- Method
- Robust linear regression (rlm, Tukey bisquare) of ln(response) on ln predictors
- Where
- Chilimo dry Afromontane forest, central Ethiopia
- Last checked
- 2026-11-02
Calculate
Height from
100.1
Stem biomass (kg)
47.06
Carbon (kg), ×0.47
172.6
CO₂e (kg), ×44/12
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 = 20, H = 12, rho = 0.6 | 100.1 | 100.1 | Computed from the printed form hand-computed from the published form; CF 1.001 applied |
| D = 50, H = 20, rho = 0.6 | 883.2 | 883.2 | Computed from the printed form hand-computed from the published form; CF 1.001 applied |
Related
- Stem biomass from rho d2h (M10, best model) · Teshome et al. 2022 · Wood density + DBH + Height
- Stem biomass from DBH (M7) · Teshome et al. 2022 · DBH
- Stem biomass from DBH, height and wood density (M9) · Teshome et al. 2022 · DBH + Height + Wood density
- Stem biomass from rho d2h (M10, best model) · same paper · Stem biomass
- Stem biomass from DBH (M7) · same paper · Stem biomass
- Stem biomass from DBH, height and wood density (M9) · same paper · Stem biomass
- Stem volume from DBH (M1) · same paper · Stem volume
- Stem volume from d2h (M2, best model) · same paper · Stem volume
- Stem volume from DBH and height (M3) · same paper · Stem volume