# Small-tree total AGB, multi-species, wood density model (Model I)

Aboveground biomass equation for 22 small-diameter (DBH ≤ 10 cm) tree species of secondary tropical forest, Mexico, from Puc-Kauil et al. 2020. 311 trees, DBH 1–10 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Puc-Kauil et al. 2020 (Tab. 1, p. 168):

> AGBtotal-tree multi-species=0.078479(ρ·DBH2·H)0.945339

Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#equation

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

```
Aboveground biomass = 0.078479 * (rho * D^2 * H)^0.945339
```

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: 0.078479 * (rho * DBH^2 * H)^0.945339, with DBH in cm, H in m, rho in g/cm3; output in kg.
Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: 22 small-diameter (DBH ≤ 10 cm) tree species of secondary tropical forest (mixed species); broadleaf
- Where: Southeast Yucatan peninsula (between Sian Ka'an, Quintana Roo, and Calakmul, Campeche). Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#where
- Biomes: tropical
- Stand: natural
- Trees measured: 311. Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#n_trees
- DBH range: 1–10 cm. Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#dbh
- Method: Nonlinear weighted OLS (SAS PROC MODEL), multi-species. Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#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

Puc-Kauil, R., Ángeles-Pérez, G., Valdéz-Lazalde, J. R., Reyes-Hernández, V. J., Dupuy-Rada, J. M., Schneider, L., Pérez-Rodríguez, P., & García-Cuevas, X. (2020). Allometric equations to estimate above-ground biomass of small-diameter mixed tree species in secondary tropical forests. iForest, 13, 165–174.

- DOI: https://doi.org/10.3832/ifor3167-013
- Access: open access
- Copy we read: https://iforest.sisef.org/pdf/?id=ifor3167-013
- Every equation from this source: https://treeallometry.org/sources/puc-kauil-2020/
- Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#source

## The facts, in the source's words

**Equation** (Tab. 1, p. 168):

> AGBtotal-tree multi-species=0.078479(ρ·DBH2·H)0.945339

Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#equation

**Trees measured** (Biomass data collection, p. 167):

> 311 trees in total

Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#quote-fit-n-trees

**Largest DBH** (Biomass data collection, p. 167):

> 22 species ranging from 1 to 10 cm DBH

Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#quote-fit-dbh-max-cm

**Our note:** Multi-species total-tree equation (stem + branches + foliage) from Model I. No correction factor is stated for this form. The paper lists adj-R2 0.96 and RMSE 0.1389. Tab. 1 prints the stem, branch and foliage component equations too; not added here.

## 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 = 6, H = 7, rho = 0.55 | 8.31 | 8.31 | Computed from the printed form: computed from the Tab. 1 coefficients |

Cite: https://treeallometry.org/equations/puc-kauil-2020-model1-multi/#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: Puc-Kauil, R., Ángeles-Pérez, G., Valdéz-Lazalde, J. R., Reyes-Hernández, V. J., Dupuy-Rada, J. M., Schneider, L., Pérez-Rodríguez, P., & García-Cuevas, X. (2020). Allometric equations to estimate above-ground biomass of small-diameter mixed tree species in secondary tropical forests. iForest, 13, 165–174. https://doi.org/10.3832/ifor3167-013

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Small-tree total AGB, multi-species, wood density model (Model I)", checked 2026-11-02, https://treeallometry.org/equations/puc-kauil-2020-model1-multi/. 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/puc-kauil-2020-model1-multi.json
Report a problem: email info@restorationscope.com with the equation id (puc-kauil-2020-model1-multi) and where the right value appears.