# Montanoa quadrangularis AGB, DBH and height (13-year restoration plantation) Aboveground biomass equation for Montanoa quadrangularis, Colombia, from Giraldo-Salazar et al. 2025. 20 trees, DBH 5.8–22.35 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it. ## Equation As printed in Giraldo-Salazar et al. 2025 (Table 7, equation 18): > AGB = 0.005 × (D^2 × H)^1.137 Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#equation In this library's units, ready to compute (aboveground biomass in kg): ``` Aboveground biomass = 1.037 * exp(-5.242 + 1.137*ln(D^2*H)) ``` Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m). The source's own form: 1.037 * exp(-5.242 + 1.137*ln(DBH^2*H)), with DBH in cm, H in m; output in kg. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#canonical ## What it covers - Output: Aboveground biomass, kg - Taxon: Montanoa quadrangularis (species), family Asteraceae; broadleaf - Where: Más Bosques para Medellín mixed restoration plantations, Aburrá valley, Medellín. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#where - Biomes: tropical, montane - Stand: plantation - Trees measured: 20. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#n_trees - DBH range: 5.8–22.35 cm. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#dbh - Height range: 6.65–17.24 m. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#height - R²: 0.937. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#r2 - Residual SE: 0.285. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#rse - Correction factor: 1.037 (applied). Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#cf - Method: ln-ln linear regression (R 4.3.2), back-transformed with e^(RSE^2/2). Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#method - Verification: read in the original source - Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#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 Giraldo-Salazar, J. M., Giraldo, J. A., Mendoza-Páez, J. S., Sierra, J. C., Rueda, J. A., & Osorio-Vélez, L. F. (2025). Allometric equations to quantify aboveground biomass in mixed-species plantations with restoration purposes in the tropical Andes. Journal of Forestry Research, 36, 44. - DOI: https://doi.org/10.1007/s11676-025-01827-w - Access: open access - Copy we read: https://link.springer.com/article/10.1007/s11676-025-01827-w - Every equation from this source: https://treeallometry.org/sources/giraldo-salazar-2025/ - Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#source ## The facts, in the source's words **Equation** (Table 7, equation 18): > AGB = 0.005 × (D^2 × H)^1.137 Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#equation **Equation** (Table 7, equation 18 (linear expression)): > ln(B) = −5.242 + 1.137 ln(D² × H) Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#quote-expression **Correction factor** (Table 7, equation 18): > e^(RSE²/2) = 1.037 Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#quote-fit-cf **Trees measured** (Table 7 / Table 2): > 20 Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#quote-fit-n-trees **Our note:** Table 7 rounds the multiplier to 0.005 (the unrounded value of exp(-5.242)*1.037 is about 0.0055), so the form is written from the linear expression, not from the printed 0.005. Table 7 gives the final equation with the correction factor e^(RSE^2/2) folded into the coefficient a; here the published form is written from the linear expression in Table 7 with the printed correction factor applied, which agrees with the printed a. Dry mass in kg, D in cm, WD in g/cm3. Trees harvested 2022-2023 in 13-year-old plantations; AGB sums leaves, twigs, branches and trunk. Ranges are for the sampled trees (Table 2). RSE is as printed in Table 5/6. ## 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 = 8, H = 8 | 6.6 | 6.6 | Computed from the printed form: computed from the published form (linear expression with printed correction factor) | | D = 15, H = 12 | 43.7 | 43.7 | Computed from the printed form: computed from the published form (linear expression with printed correction factor) | | D = 25, H = 16 | 193.7 | 193.7 | Computed from the printed form: computed from the published form (linear expression with printed correction factor) | Cite: https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/#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: Giraldo-Salazar, J. M., Giraldo, J. A., Mendoza-Páez, J. S., Sierra, J. C., Rueda, J. A., & Osorio-Vélez, L. F. (2025). Allometric equations to quantify aboveground biomass in mixed-species plantations with restoration purposes in the tropical Andes. Journal of Forestry Research, 36, 44. https://doi.org/10.1007/s11676-025-01827-w Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Montanoa quadrangularis AGB, DBH and height (13-year restoration plantation)", checked 2026-11-02, https://treeallometry.org/equations/giraldo-salazar-2025-montanoa/. 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/giraldo-salazar-2025-montanoa.json Report a problem: email info@restorationscope.com with the equation id (giraldo-salazar-2025-montanoa) and where the right value appears.