# Kintampo woodlands mixed-species AGB, M2: dbh and wood density

Aboveground biomass equation for 31 woodland tree species harvested for charcoal, Ghana, from Aabeyir et al. 2020. 745 trees, DBH 5–48.2 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Aabeyir et al. 2020 (Table 5 (parameter estimates)):

> M2 a2 0.202 0.166–0.238 0.162–0.242 b2 1.205 1.180–1.231

Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#equation

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

```
Aboveground biomass = 0.202 * rho * D^(2 * 1.205)
```

Inputs: rho = Wood density (oven-dry mass / green volume) (g/cm³); D = Diameter at breast height (1.3 m) (cm).
The source's own form: 0.202 * WD * DBH^(2 * 1.205), with DBH in cm, WD in g/cm3; output in kg.
Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: 31 woodland tree species harvested for charcoal (mixed species); broadleaf
- Where: Kintampo Municipality, forest-savanna transition zone, Ghana. Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 745. Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#n_trees
- DBH range: 5–48.2 cm. Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#dbh
- Method: non-linear regression (variance proportional to squared mean). Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#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

Aabeyir, R., Adu-Bredu, S., Agyare, W.A., Weir, M.J.C. (2020). Allometric models for estimating aboveground biomass in the tropical woodlands of Ghana, West Africa. Forest Ecosystems, 7, 41.

- DOI: https://doi.org/10.1186/s40663-020-00250-3
- Access: open access
- Copy we read: https://link.springer.com/article/10.1186/s40663-020-00250-3
- Every equation from this source: https://treeallometry.org/sources/aabeyir-2020/
- Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#source

## The facts, in the source's words

**Equation** (Table 5 (parameter estimates)):

> M2 a2 0.202 0.166–0.238 0.162–0.242 b2 1.205 1.180–1.231

Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#equation

**Equation** (Table 3 (model forms)):

> M2 a2[ρ(dbh)^(2b2)]

Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#quote-expression

**Trees measured** (Abstract):

> Destructive sampling was carried out on 745 trees

Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#quote-fit-n-trees

**Largest DBH** (Modelling process, Data description):

> The dbh of individual trees ranged from 5.0 to 48.2 cm

Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#quote-fit-dbh-max-cm

**Our note:** Mixed-species model; AGB is the sum of logs, small branches, twigs and leaves, so foliage is included. Fitted by non-linear regression, so no back-transformation correction. Wood density ρ is the species mean of disc samples (oven-dry mass / volume), in g/cm³. Coefficients are the Table 5 estimates rounded 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 = 25, rho = 0.65 | 307 | 307 | Computed from the printed form: hand-computed from the published form |
| D = 40, rho = 0.65 | 953 | 953 | Computed from the printed form: hand-computed from the published form |

Cite: https://treeallometry.org/equations/aabeyir-2020-m2/#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: Aabeyir, R., Adu-Bredu, S., Agyare, W.A., Weir, M.J.C. (2020). Allometric models for estimating aboveground biomass in the tropical woodlands of Ghana, West Africa. Forest Ecosystems, 7, 41. https://doi.org/10.1186/s40663-020-00250-3

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Kintampo woodlands mixed-species AGB, M2: dbh and wood density", checked 2026-11-02, https://treeallometry.org/equations/aabeyir-2020-m2/. 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/aabeyir-2020-m2.json
Report a problem: email info@restorationscope.com with the equation id (aabeyir-2020-m2) and where the right value appears.