# Faidherbia albida in parklands, DBH only (M1, selected)

Aboveground biomass equation for Faidherbia albida, Ethiopia, from Darcha et al. 2025. 35 trees, DBH 8–31 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Darcha et al. 2025 (Abstract; Table 4 M1 (CF 1.05)):

> Ln (AGB) = -2.85 + 2.4 ln (DBH)

Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#equation

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

```
Aboveground biomass = 1.05 * exp(-2.85 + 2.4 * ln(D))
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 1.05 * exp(-2.85 + 2.4 * ln(DBH)), with DBH in cm; output in kg.
Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Faidherbia albida (species), family Fabaceae; broadleaf
- Where: Parklands of Kilte Awlaelo, Hawzen and Ganta-Afeshum districts, eastern Tigray, Ethiopia (about 1850-2610 m). Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#where
- Biomes: tropical, montane, dryland
- Stand: agroforestry
- Trees measured: 35. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#n_trees
- DBH range: 8–31 cm. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#dbh
- Height range: 3–11.5 m. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#height
- R²: 0.88. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#r2
- Residual SE: 0.3. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#rse
- Correction factor: 1.05 (applied). Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#cf
- Method: OLS on ln-transformed data, adjusted R2. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#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

Darcha, G., Birhane, E., Kassa, H., Gebrewahid, Y. (2025). Allometric equations to predict aboveground biomass and carbon stock of Faidherbia albida in parkland agroforestry. Forest Science and Technology, 21(3), 221–232.

- DOI: https://doi.org/10.1080/21580103.2025.2497246
- Access: open access
- Every equation from this source: https://treeallometry.org/sources/darcha-2025/
- Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#source

## The facts, in the source's words

**Equation** (Abstract; Table 4 M1 (CF 1.05)):

> Ln (AGB) = -2.85 + 2.4 ln (DBH)

Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#equation

**Fit** (Table 4, M1):

> Ln (TAGB) = a0 + a1 ln (DBH) ... −2.85 2.4 ... CF 1.05 ... 0.88 ... 0.3

Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#quote-fit

**Our note:** CF 1.05 (Table 4) multiplies the back-transformed exponential. DBH taken at 1.37 m per the paper (also given as 1.3 m in the methods). Only 35 trees and DBH 8-31 cm.

## 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 = 15 | 40.4 | 40.4 | Computed from the printed form: hand-computed from the published form |
| D = 30 | 213 | 213 | Computed from the printed form: hand-computed from the published form |

Cite: https://treeallometry.org/equations/darcha-2025-m1-dbh/#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: Darcha, G., Birhane, E., Kassa, H., Gebrewahid, Y. (2025). Allometric equations to predict aboveground biomass and carbon stock of Faidherbia albida in parkland agroforestry. Forest Science and Technology, 21(3), 221–232. https://doi.org/10.1080/21580103.2025.2497246

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Faidherbia albida in parklands, DBH only (M1, selected)", checked 2026-11-01, https://treeallometry.org/equations/darcha-2025-m1-dbh/. 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/darcha-2025-m1-dbh.json
Report a problem: email info@restorationscope.com with the equation id (darcha-2025-m1-dbh) and where the right value appears.