# Cameroon semi-deciduous forest total wood volume, Eq. (4), power product in DBH and height

Total volume equation for 23 timber species of semi-deciduous forest (mixed), Cameroon, from Dorisca et al. 2011. 55 trees, DBH 10–120 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Dorisca et al. 2011 (Équation (4), Résultats / Tableau II, pp. 92-95):

> V̂ = 1 302,5 + 63,6 Dbh2,5 H0,16

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#equation

In this library's units, ready to compute (total volume in m³):

```
Total volume = (1302.5 + 63.6 * D^2.5 * (H * 100)^0.16) / 1e6
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: (1302.5 + 63.6 * DBH^2.5 * Hcm^0.16) / 1000, with DBH in cm, Hcm in cm; output in dm3.
Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#canonical

## What it covers

- Output: Total volume, m³
- Taxon: 23 timber species of semi-deciduous forest (mixed) (mixed species); broadleaf
- Where: Two forest management units (UFA 10-026 and 10-051), south-east Cameroon, about 1,500 mm rain per year. Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 55. Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#n_trees
- DBH range: 10–120 cm. Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#dbh
- R²: 0.94. Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#r2
- Method: gls/gnls (nlme in R), variance modelled as a power of DBH; R2 is the generalized R2 (model efficiency). Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#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

Dorisca, S., Durrieu de Madron, L., Fontez, B., Giraud, A., Riera, B. (2011). Établissement d'équations entre le diamètre et le volume total de bois des arbres, adaptées au Cameroun. Bois et Forêts des Tropiques, 308(2), 87-95.

- DOI: https://doi.org/10.19182/bft2011.308.a20477
- Access: open access
- Copy we read: https://revues.cirad.fr/index.php/BFT/article/download/20477/20236
- Every equation from this source: https://treeallometry.org/sources/dorisca-2011/
- Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#source

## The facts, in the source's words

**Equation** (Équation (4), Résultats / Tableau II, pp. 92-95):

> V̂ = 1 302,5 + 63,6 Dbh2,5 H0,16

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#equation

**Trees measured** (Résumé, p. 88):

> 55 arbres de 10 à 120 cm de diamètre, appartenant à 23 espèces

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#quote-fit-n-trees

**Smallest DBH** (Comparaison des cinq modèles, p. 94):

> La plage de validité de ces équations est de 10 à 120 cm.

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#quote-fit-dbh-min-cm

**R²** (Tableau II, p. 95):

> R² généralisé 0,94

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#quote-fit-r2

**units** (Méthodes de calcul, p. 91):

> Vi désigne le volume total de bois jusqu'à un diamètre découpe de 1 cm (en cm3), Dbhi désigne le diamètre à hauteur de poitrine (en cm) et Hi la hauteur (en cm)

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#quote-units

**Our note:** Total wood volume of the tree (stem and branches) down to a 1 cm diameter cut-off, not biomass. The paper fits V in cm3 with DBH in cm and, per its Methods, H in cm; the unit list has no cm3, so the published form is divided by 1000 and given in dm3, and the canonical form is divided by 1e6 to give m3 (and H in m is multiplied by 100). The paper says biomass follows from multiplying volume by specific density plus a small foliage correction, but gives no equation, so no biomass equation is stored. Sample 55 trees, DBH over 10 cm, more than 17 above 45 cm. R2 is the generalized R2 of Mayer and Butler (1993).

## 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 = 20, H = 20 | 0.385 | 0.385 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 50, H = 30 | 4.05 | 4.05 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 100, H = 40 | 24 | 24 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/dorisca-2011-power-d-h/#checks

## How to cite

Cite the source for the equation: Dorisca, S., Durrieu de Madron, L., Fontez, B., Giraud, A., Riera, B. (2011). Établissement d'équations entre le diamètre et le volume total de bois des arbres, adaptées au Cameroun. Bois et Forêts des Tropiques, 308(2), 87-95. https://doi.org/10.19182/bft2011.308.a20477

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Cameroon semi-deciduous forest total wood volume, Eq. (4), power product in DBH and height", checked 2026-11-02, https://treeallometry.org/equations/dorisca-2011-power-d-h/. 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/dorisca-2011-power-d-h.json
Report a problem: email info@restorationscope.com with the equation id (dorisca-2011-power-d-h) and where the right value appears.