# Acacia-Commiphora total AGB, M7 (rho D2 H, crown width)

Aboveground biomass equation for Eleven woody species of the Acacia-Commiphora biome (mixed), Ethiopia, from Amanuel et al. 2024. 140 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Amanuel et al. 2024 (Table 3, AGBTotal rows, p. 6; model form in Table 1, p. 4):

> 7a   –0.4699   0.1987   0.5410   0.0601   0.5932   0.2019   0.41b   0.83b   0.82b

Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#equation

In this library's units, ready to compute (aboveground biomass in kg):

```
Aboveground biomass = exp(-0.4699 + 0.5410 * ln(rho * D^2 * H) + 0.5932 * ln(CD))
```

Inputs: rho = Wood density (oven-dry mass / green volume) (g/cm³); D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m); CD = Crown diameter (m).
The source's own form: exp(-0.4699 + 0.5410 * ln(rho * D^2 * H) + 0.5932 * ln(CW)), with CW in m, D in cm, H in m, rho in g/cm3; output in kg.
Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Eleven woody species of the Acacia-Commiphora biome (mixed) (mixed species); broadleaf
- Where: Bena-Tsemay district, southern Ethiopia. Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#where
- Biomes: tropical, dryland
- Stand: natural
- Trees measured: 140. Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#n_trees
- R²: 0.83. Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#r2
- Method: ln-ln multiple linear regression (SAS); no correction factor stated. Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#checked_at

A missing fit statistic is one the source doesn't state, or that we haven't recorded; it is never estimated. Outside the stated DBH range or region, the equation is an extrapolation.

## Source

Amanuel, W., Tadesse, C., Molla, M., Getinet, D., Mekonnen, Z. (2024). Allometric equation for estimating aboveground biomass of Acacia-Commiphora forest, southern Ethiopia. Journal of Ecology and Environment, 48, 20.

- DOI: https://doi.org/10.5141/jee.24.036
- Access: open access
- Copy we read: https://www.e-jecoenv.org/journal/download_pdf.php?doi=10.5141/jee.24.036
- Every equation from this source: https://treeallometry.org/sources/amanuel-2024/
- Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#source

## The facts, in the source's words

**Equation** (Table 3, AGBTotal rows, p. 6; model form in Table 1, p. 4):

> 7a   –0.4699   0.1987   0.5410   0.0601   0.5932   0.2019   0.41b   0.83b   0.82b

Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#equation

**model form** (Table 1, p. 4):

> AGBest. = exp {α + β1Ln (ρ.D2.H) + β2Ln (CW)}

Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#quote-model-form

**Trees measured** (Methods, Biomass measurement, p. 3):

> The biomass of the 140 individual trees was considered for biomass model development.

Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#quote-fit-n-trees

**R²** (Table 3, AGBTotal, columns R2 / Adj-R2):

> 7a   –0.4699   0.1987   0.5410   0.0601   0.5932   0.2019   0.41b   0.83b   0.82b

Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#quote-fit-r2

**Our note:** Total aboveground dry biomass (stem + branches + foliage summed). In the paper D is DBH (cm), DSH30 is stem diameter at 30 cm (mapped to D30), CW is crown width (mapped to CD, m), rho is basic wood density (g/cm3). R2 shown is the printed R2 (Adj-R2 is within 0.01). No back-transformation correction factor is printed, so none is applied. The paper prints the mean D (12.61 cm) and a D range width of 29 cm but no min or max, so no DBH range is stored. RMSE printed in Table 3 is on the log scale. n = 140 is the full sample; Methods (p. 3) say 30% was held out for validation, so the fitted n may be ~98.

## Checks this equation passes

On every build, the library's form and the source's own form (in its units) must both give these values within 1%.

| Inputs | Expected | We get | From |
| --- | --- | --- | --- |
| D = 8, H = 4, rho = 0.7, CD = 3 | 19.9 | 19.9 | Computed from the printed form: computed from the published form (coefficients as printed, no correction factor) |
| D = 15, H = 6, rho = 0.7, CD = 4.5 | 62.1 | 62.1 | Computed from the printed form: computed from the published form (coefficients as printed, no correction factor) |
| D = 25, H = 8, rho = 0.7, CD = 6 | 149.6 | 149.6 | Computed from the printed form: computed from the published form (coefficients as printed, no correction factor) |

Cite: https://treeallometry.org/equations/amanuel-2024-total-m7/#checks

The calculator on the page shows carbon as biomass × 0.47 (IPCC 2006 Guidelines, Vol. 4, Ch. 4, Table 4.3) and CO₂e as carbon × 44/12.

## How to cite

Cite the source for the equation: Amanuel, W., Tadesse, C., Molla, M., Getinet, D., Mekonnen, Z. (2024). Allometric equation for estimating aboveground biomass of Acacia-Commiphora forest, southern Ethiopia. Journal of Ecology and Environment, 48, 20. https://doi.org/10.5141/jee.24.036

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Acacia-Commiphora total AGB, M7 (rho D2 H, crown width)", checked 2026-11-02, https://treeallometry.org/equations/amanuel-2024-total-m7/. Data CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Quotes are the authors' words.

Data for this equation: https://treeallometry.org/data/equations/amanuel-2024-total-m7.json
Report a problem: email info@restorationscope.com with the equation id (amanuel-2024-total-m7) and where the right value appears.