# Alnus acuminata AGB, DBH only (13-year restoration plantation)

Aboveground biomass equation for Alnus acuminata, Colombia, from Giraldo-Salazar et al. 2025. 23 trees, DBH 6.4–29.6 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 15):

> AGB = 0.097 × D^2.371

Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#equation

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

```
Aboveground biomass = 1.029 * exp(-2.361 + 2.371*ln(D))
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 1.029 * exp(-2.361 + 2.371*ln(DBH)), with DBH in cm; output in kg.
Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Alnus acuminata (species), family Betulaceae; broadleaf
- Where: Más Bosques para Medellín mixed restoration plantations, Aburrá valley, Medellín. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#where
- Biomes: tropical, montane
- Stand: plantation
- Trees measured: 23. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#n_trees
- DBH range: 6.4–29.6 cm. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#dbh
- Height range: 7.3–19.85 m. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#height
- R²: 0.939. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#r2
- Residual SE: 0.25. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#rse
- Correction factor: 1.029 (applied). Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#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-alnus/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#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-alnus/#source

## The facts, in the source's words

**Equation** (Table 7, equation 15):

> AGB = 0.097 × D^2.371

Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#equation

**Equation** (Table 7, equation 15 (linear expression)):

> ln(AGB) = −2.361 + 2.371 ln(D)

Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#quote-expression

**Correction factor** (Table 7, equation 15):

> e^(RSE²/2) = 1.029

Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#quote-fit-cf

**Trees measured** (Table 7 / Table 2):

> 23

Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#quote-fit-n-trees

**Our note:**  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 | 13.4 | 13.4 | Computed from the printed form: computed from the published form (linear expression with printed correction factor) |
| D = 15 | 59.6 | 59.6 | Computed from the printed form: computed from the published form (linear expression with printed correction factor) |
| D = 25 | 200 | 200 | Computed from the printed form: computed from the published form (linear expression with printed correction factor) |

Cite: https://treeallometry.org/equations/giraldo-salazar-2025-alnus/#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), "Alnus acuminata AGB, DBH only (13-year restoration plantation)", checked 2026-11-02, https://treeallometry.org/equations/giraldo-salazar-2025-alnus/. 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-alnus.json
Report a problem: email info@restorationscope.com with the equation id (giraldo-salazar-2025-alnus) and where the right value appears.