# Pruned Faidherbia albida total wood mass from DBH (Eq. 3.7)

Aboveground biomass equation (without leaves) for Faidherbia albida, Cameroon, from Ambomo Tsanga et al. 2026. 18 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Ambomo Tsanga et al. 2026 (Table II, p. 10):

> Eq 3.7 ln(TDWb) = -0.901 + 1.978 * ln(D)

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#equation

In this library's units, ready to compute (aboveground biomass, without leaves in kg):

```
Aboveground biomass, without leaves = 1.06 * exp(-0.901 + 1.978 * ln(D))
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 1.06 * exp(-0.901 + 1.978 * ln(D)), with D in cm; output in kg.
Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#canonical

This total leaves out leaves (foliage), as the source defines it.

## What it covers

- Output: Aboveground biomass, without leaves, kg
- Taxon: Faidherbia albida (species), family Fabaceae; broadleaf
- Where: Gané and Sirlawé villages, Mayo-Danay, Far North region, Cameroon. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#where
- Biomes: tropical, dryland
- Stand: agroforestry
- Trees measured: 18. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#n_trees
- Height range: 9–14 m. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#height
- Correction factor: 1.06 (applied). Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#cf
- Method: log-log regression (OLS). Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#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

Ambomo Tsanga, F., Akodewou, A., Tapsou, J.-M., et al. (2026). Allometric models for estimating fuelwood and above-ground wood dry mass of pruned Faidherbia albida trees in northern Cameroon. Bois et Forêts des Tropiques, 363, 1-17.

- DOI: https://doi.org/10.19182/bft2026.363.a37930
- Access: open access
- Copy we read: https://hal.science/hal-05751272v1/file/BFT363-2026-Ambomo%252BTsanga%252Bet%252Bal-1-17.pdf
- Every equation from this source: https://treeallometry.org/sources/ambomo-tsanga-2026/
- Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#source

## The facts, in the source's words

**Equation** (Table II, p. 10):

> Eq 3.7 ln(TDWb) = -0.901 + 1.978 * ln(D)

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#equation

**Correction factor** (Table II footnote 1, p. 10):

> Bias correction coefficient to transform predictions back to the original scale while accounting for the variance of the residuals.

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#quote-fit-cf

**Trees measured** (Table I caption, p. 9):

> the sample of 18 Faidherbia albida trees

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#quote-fit-n-trees

**Our note:** Response is TDWb, total above-ground wood dry mass (pruned wood plus post-pruning wood of trunk and branch stumps); foliage was not weighed, so it is excluded. Pruned-wood mass uses a 0.439 dry-matter fraction and post-pruning mass uses volume x 0.411 g cm-3 mean basic density, so it is a semi-destructive estimate. The back-transform applies the printed CF (1.06, given to two decimals). Natural log assumed from the paper's ln notation. DBH range not stored: Table I gives 31.8 to 110.4 cm but the text gives 28 to 183 cm for the 18 trees. Crown-area (Ca) equations from the same table are not added because Ca is not a canonical variable (computed as an ellipse area from two crown diameters).

## 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 = 50 | 988 | 988 | Computed from the printed form: computed from the Table II coefficients with the printed CF 1.06 |
| D = 90 | 3,159 | 3,159 | Computed from the printed form: computed from the Table II coefficients with the printed CF 1.06 |

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/#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: Ambomo Tsanga, F., Akodewou, A., Tapsou, J.-M., et al. (2026). Allometric models for estimating fuelwood and above-ground wood dry mass of pruned Faidherbia albida trees in northern Cameroon. Bois et Forêts des Tropiques, 363, 1-17. https://doi.org/10.19182/bft2026.363.a37930

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Pruned Faidherbia albida total wood mass from DBH (Eq. 3.7)", checked 2026-11-02, https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d/. 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/ambomo-tsanga-2026-tdwb-d.json
Report a problem: email info@restorationscope.com with the equation id (ambomo-tsanga-2026-tdwb-d) and where the right value appears.