# Raphia laurentii AGB from stem base diameter (m13, mean petiole diameter ≥5 cm)

Aboveground biomass equation for Raphia laurentii, Congo - Brazzaville, from Bocko et al. 2023. 60 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Bocko et al. 2023 (Table 2, m13 row (AGB in kg dry mass); CF defined in Methods, p. 5):

> m13 ln(AGB) = a + b × ln(D) -5.737 3.048 0.69 0.45 77.3 48.07 -3.76 1.11

Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#equation

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

```
Aboveground biomass = 1.11 * exp(-5.737 + 3.048 * ln(DRC))
```

Inputs: DRC = Root collar / stem base diameter (cm).
The source's own form: 1.11 * exp(-5.737 + 3.048 * ln(D)), with D in cm; output in kg.
Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Raphia laurentii (species); palm
- Where: Peat swamp forest near Bolembe, Likouala Department, Republic of the Congo. Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 60. Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#n_trees
- Correction factor: 1.11 (applied). Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#cf
- Method: ln-ln linear regression times correction factor CF = exp(RSE²/2). Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#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

Bocko, Y.E., Panzou, G.J.L., Dargie, G.C., Mampouya, Y.E.W., Mbemba, M., Loumeto, J.J., Lewis, S.L. (2023). Allometric equation for Raphia laurentii De Wild, the commonest palm in the central Congo peatlands. PLoS ONE, 18(4), e0273591.

- DOI: https://doi.org/10.1371/journal.pone.0273591
- Access: open access
- Copy we read: https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0273591&type=printable
- Every equation from this source: https://treeallometry.org/sources/bocko-2023/
- Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#source

## The facts, in the source's words

**Equation** (Table 2, m13 row (AGB in kg dry mass); CF defined in Methods, p. 5):

> m13 ln(AGB) = a + b × ln(D) -5.737 3.048 0.69 0.45 77.3 48.07 -3.76 1.11

Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#equation

**Note** (Development of allometric equations, p. 5):

> The aboveground biomass estimated from each logarithmic linear model was multiplied by the following correction factor

Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#quote-notes

**Trees measured** (Table 2, mean petiole diameter range (n) column):

> Table 2 range (n): 5–15 cm (60)

Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#quote-fit-n-trees

**Our note:** Whole-palm aboveground dry biomass (stem, sheaths, petioles, rachis and leaflets, so foliage is included). Stem base diameter was measured about 13 cm above the ground, mapped to DRC (root collar / stem base diameter); the fitted range of this variable is 8.20–35.40 cm (Table 1, all 90 palms), which is not DBH so it is not stored as a DBH range. Fitted on palms with mean petiole diameter 5–15 cm (60 palms); ranges of the subset are not given. CF is the printed correction factor (rounded to 2 decimals) and is applied in the expression. Single-predictor model: the paper's better models use the sum of petiole diameters (not a canonical variable; not captured), so this is a fallback for when only diameter or height is measured. R² adj printed: 0.69; RSE 0.45 (Table 2).

## 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 |
| --- | --- | --- | --- |
| DRC = 10 | 4 | 4 | Computed from the printed form: computed from the published form (coefficients and CF as printed) |
| DRC = 20 | 33.1 | 33.1 | Computed from the printed form: computed from the published form (coefficients and CF as printed) |
| DRC = 30 | 114 | 114 | Computed from the printed form: computed from the published form (coefficients and CF as printed) |

Cite: https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/#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: Bocko, Y.E., Panzou, G.J.L., Dargie, G.C., Mampouya, Y.E.W., Mbemba, M., Loumeto, J.J., Lewis, S.L. (2023). Allometric equation for Raphia laurentii De Wild, the commonest palm in the central Congo peatlands. PLoS ONE, 18(4), e0273591. https://doi.org/10.1371/journal.pone.0273591

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Raphia laurentii AGB from stem base diameter (m13, mean petiole diameter ≥5 cm)", checked 2026-11-02, https://treeallometry.org/equations/bocko-2023-m13-base-diameter-ge5/. 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/bocko-2023-m13-base-diameter-ge5.json
Report a problem: email info@restorationscope.com with the equation id (bocko-2023-m13-base-diameter-ge5) and where the right value appears.