# Total wood volume from DBH and height (Model 3, Table 5)

Total volume equation for Pterocarpus angolensis, Namibia, Angola, from De Cauwer et al. 2020. 69 trees, DBH 9–73 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in De Cauwer et al. 2020 (Table 5, Model 3):

> V tot = exp(a + b 1 *lnDBH + b 2 *H) ... -8.626 *** 2.232 *** 0.041 ***

Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#equation

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

```
Total volume = exp(-8.626 + 2.232 * ln(D) + 0.041 * H)
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: exp(-8.626 + 2.232 * ln(DBH) + 0.041 * H), with DBH in cm, H in m; output in m3.
Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#canonical

## What it covers

- Output: Total volume, m³
- Taxon: Pterocarpus angolensis (species), family Fabaceae; broadleaf
- Where: Baikiaea-Pterocarpus woodlands of northern Namibia and southern Angola (MAP 480-700 mm). Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#where
- Biomes: tropical, dryland
- Stand: natural
- Trees measured: 69. Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#n_trees
- DBH range: 9–73 cm. Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#dbh
- R²: 0.96. Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#r2
- Method: Regression on ln scale with Baskerville correction in intercept; adjusted R2. Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-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

De Cauwer, V., Beeckman, H., Kleinn, C., Moses, M., Nott, A., Seifert, T., Muys, B. (2020). Improving the knowledge base for tropical dry forest management in southern Africa: Regional volume models for Pterocarpus angolensis. Forest Ecology and Management, 477, 118485.

- DOI: https://doi.org/10.1016/j.foreco.2020.118485
- Access: open access
- Copy we read: https://lirias.kuleuven.be/retrieve/00adf4e9-cc77-4da0-88bc-0454a2f00a1c
- Every equation from this source: https://treeallometry.org/sources/de-cauwer-2020/
- Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#source

## The facts, in the source's words

**Equation** (Table 5, Model 3):

> V tot = exp(a + b 1 *lnDBH + b 2 *H) ... -8.626 *** 2.232 *** 0.041 ***

Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#equation

**Trees measured** (Section 3.1):

> Models for Vtot were established with the data of 69 trees

Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#quote-fit-n-trees

**DBH range** (Table 5 caption):

> diameter at breast height (DBH) in the range of 9 to 73 cm

Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#quote-fit-dbh

**Our note:** Table 5 caption: 'models with intercept a including the Baskerville correction factor', so the correction is already inside the printed intercept and nothing is added here (no separate CF value is printed). Total over-bark wood volume of the tree including branches and stump. Paper's RSE (0.49 m3 calibration) is on the volume scale, not log scale, so fit.rse is left out; R2 is the printed adjusted R2. Height enters linearly (b2*H), not as ln(H), as printed.

## 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 = 8 | 0.2 | 0.2 | Computed from the printed form: hand-computed from the published form |
| D = 50, H = 14 | 1.97 | 1.97 | Computed from the printed form: hand-computed from the published form |

Cite: https://treeallometry.org/equations/de-cauwer-2020-vtot-d-h/#checks

## How to cite

Cite the source for the equation: De Cauwer, V., Beeckman, H., Kleinn, C., Moses, M., Nott, A., Seifert, T., Muys, B. (2020). Improving the knowledge base for tropical dry forest management in southern Africa: Regional volume models for Pterocarpus angolensis. Forest Ecology and Management, 477, 118485. https://doi.org/10.1016/j.foreco.2020.118485

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Total wood volume from DBH and height (Model 3, Table 5)", checked 2026-11-02, https://treeallometry.org/equations/de-cauwer-2020-vtot-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/de-cauwer-2020-vtot-d-h.json
Report a problem: email info@restorationscope.com with the equation id (de-cauwer-2020-vtot-d-h) and where the right value appears.