# Kintampo woodlands mixed-species AGB, M6 (best model): dbh, height 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)): > M6 a6 0.058 0.049–0.067 0.046–0.070 b6 0.999 0.983–1.015 Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#equation In this library's units, ready to compute (aboveground biomass in kg): ``` Aboveground biomass = 0.0580 * rho * (D^2 * H)^0.999 ``` Inputs: rho = Wood density (oven-dry mass / green volume) (g/cm³); D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m). The source's own form: 0.0580 * WD * (DBH^2 * HT)^0.999, with DBH in cm, HT in m, WD in g/cm3; output in kg. Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#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-m6/#where - Biomes: tropical - Stand: natural - Trees measured: 745. Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#n_trees - DBH range: 5–48.2 cm. Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#dbh - Method: non-linear regression (variance proportional to squared mean). Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#method - Verification: read in the original source - Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#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-m6/#source ## The facts, in the source's words **Equation** (Table 5 (parameter estimates)): > M6 a6 0.058 0.049–0.067 0.046–0.070 b6 0.999 0.983–1.015 Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#equation **Equation** (Table 3 (model forms)): > M6 a6[ρ((dbh)^2H)^b6] Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#quote-expression **Trees measured** (Abstract): > Destructive sampling was carried out on 745 trees Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#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-m6/#quote-fit-dbh-max-cm **Equation** (Abstract): > AGB = 0.0580ρ((dbh)2H)0.999 Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#quote-expression-2 **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. Abstract prints a6 as 0.0580; Table 5 prints 0.058. The abstract value is used. ## 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, H = 12, rho = 0.65 | 280 | 280 | Computed from the printed form: hand-computed from the published form | | D = 40, H = 12, rho = 0.65 | 717 | 717 | Computed from the printed form: hand-computed from the published form | Cite: https://treeallometry.org/equations/aabeyir-2020-m6/#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, M6 (best model): dbh, height and wood density", checked 2026-11-02, https://treeallometry.org/equations/aabeyir-2020-m6/. 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-m6.json Report a problem: email info@restorationscope.com with the equation id (aabeyir-2020-m6) and where the right value appears.