# Pruned Faidherbia albida total wood mass from D²H (Eq. 3.5)

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 3.5 ln(TDWb) = -2.050 + 0.872 * ln(D²H)

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#equation

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

```
Aboveground biomass, without leaves = 1.06 * exp(-2.050 + 0.872 * ln(D^2 * H))
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: 1.06 * exp(-2.050 + 0.872 * ln(D^2 * H)), with D in cm, H in m; output in kg.
Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#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-d2h/#where
- Biomes: tropical, dryland
- Stand: agroforestry
- Trees measured: 18. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#n_trees
- Height range: 9–14 m. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#height
- Correction factor: 1.06 (applied). Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#cf
- Method: log-log regression (OLS). Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#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-d2h/#source

## The facts, in the source's words

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

> Eq 3.5 ln(TDWb) = -2.050 + 0.872 * ln(D²H)

Cite: https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/#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-d2h/#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-d2h/#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, H = 10 | 933 | 933 | Computed from the printed form: computed from the Table II coefficients with the printed CF 1.06 |
| D = 90, H = 13 | 3,270 | 3,270 | 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-d2h/#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 D²H (Eq. 3.5)", checked 2026-11-02, https://treeallometry.org/equations/ambomo-tsanga-2026-tdwb-d2h/. 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-d2h.json
Report a problem: email info@restorationscope.com with the equation id (ambomo-tsanga-2026-tdwb-d2h) and where the right value appears.