# Root biomass from basal area at breast height, Vitellaria paradoxa

Root biomass equation for Vitellaria paradoxa, Burkina Faso, from Koala et al. 2017. 10 trees, DBH 2.55–10.82 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Koala et al. 2017 (Table 2, BA1.3 row, Vitellaria paradoxa, p. 7):

> BA1.3 5759.0 6001.4 1.15 0.17 0.85 0.58 <0.0001

Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#equation

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

```
Root biomass = 5759.0 * (0.7853982 * (D/100)^2)^1.15
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 5759.0 * (0.7853982 * (DBH/100)^2)^1.15, with DBH in cm; output in kg.
Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#canonical

## What it covers

- Output: Root biomass, kg
- Taxon: Vitellaria paradoxa (species), family Sapotaceae; broadleaf
- Where: Tiogo and Laba state forests, Burkina Faso (north Sudanian savanna-woodland). Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#where
- Biomes: tropical, dryland
- Stand: natural
- Trees measured: 10. Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#n_trees
- DBH range: 2.55–10.82 cm. Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#dbh
- R²: 0.85. Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#r2
- Method: nonlinear regression, BGB = a × BA1.3^b. Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#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

Koala, J., Sawadogo, L., Savadogo, P., Aynekulu, E., Heiskanen, J., Saïd, M. (2017). Allometric equations for below-ground biomass of four key woody species in West African savanna-woodlands. Silva Fennica, 51(3), article 1631.

- DOI: https://doi.org/10.14214/sf.1631
- Access: open access
- Copy we read: https://silvafennica.fi/pdf/1631
- Every equation from this source: https://treeallometry.org/sources/koala-2017/
- Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#source

## The facts, in the source's words

**Equation** (Table 2, BA1.3 row, Vitellaria paradoxa, p. 7):

> BA1.3 5759.0 6001.4 1.15 0.17 0.85 0.58 <0.0001

Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#equation

**Equation** (Eq. 4, p. 5):

> BGB = a × BA1.3b + ε

Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#quote-expression

**Units** (Table 2 caption, p. 7):

> basal area (m2) at 1.3 m above ground level (BA1.3)

Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#quote-published-units

**Trees measured** (Table 1, p. 4 (N, then C0.2, C1.3 columns)):

> Vitellaria paradoxa 10 29.0±9.1 14 40 19.5±8.5 8 34

Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#quote-fit-n-trees

**Our note:** Not one of the authors' best models (they recommend basal area at 0.2 m, BA0.2, which has no canonical diameter variable here, and BA×H terms); this is the breast-height-only fit from Table 2, included because it can be used with DBH. Paper input is basal area at 1.3 m in m2; here BA1.3 is computed from DBH as pi*D^2/4 (0.7853982*(D/100)^2) in both forms. Fit dbh range is the printed C1.3 min and max divided by pi (circumference at 1.3 m, Table 1). BGB is stump plus coarse roots (roots over 5 mm for the non-protected species) from excavation, oven-dry. Table 2 prints a and b to 1 or 2 decimals. No correction factor is stated. Only the BA1.3-only models are included: the paper's height columns are labelled cm while the coefficients only make sense with H in metres, so the BA×H and H models are left out. For forked trees the paper's C1.3 is the quadratic sum of stem circumferences (Eq. 1, p. 4), so D here is the equivalent diameter sqrt(ΣDi²).

## 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 = 10 | 21.9 | 21.9 | Computed from the printed form: computed from the published form with BA1.3 = pi*D^2/4 in m2 |

Cite: https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/#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: Koala, J., Sawadogo, L., Savadogo, P., Aynekulu, E., Heiskanen, J., Saïd, M. (2017). Allometric equations for below-ground biomass of four key woody species in West African savanna-woodlands. Silva Fennica, 51(3), article 1631. https://doi.org/10.14214/sf.1631

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Root biomass from basal area at breast height, Vitellaria paradoxa", checked 2026-11-01, https://treeallometry.org/equations/koala-2017-bgb-ba13-vitellaria-paradoxa/. 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/koala-2017-bgb-ba13-vitellaria-paradoxa.json
Report a problem: email info@restorationscope.com with the equation id (koala-2017-bgb-ba13-vitellaria-paradoxa) and where the right value appears.