# Quercus group 2 (obtusata, coccolobifolia, sideroxyla): stem biomass

Stem biomass equation for Quercus group 2 (Q. obtusata, Q. coccolobifolia, Q. sideroxyla), Mexico, from Cortés-Sánchez et al. 2019. DBH 4.8–40.5 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

Fitted on Quercus obtusata, Quercus coccolobifolia, Quercus sideroxyla.

## Equation

As printed in Cortés-Sánchez et al. 2019 (Table 8, Grupo 2):

> Bf = 0.072967 × Dn^2.087881 × At^0.32756

Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#equation

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

```
Stem biomass = 0.072967 * D^2.087881 * H^0.32756
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: 0.072967 * Dn^2.087881 * At^0.32756, with At in m, Dn in cm; output in kg.
Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#canonical

## What it covers

- Output: Stem biomass, kg
- Taxon: Quercus group 2 (Q. obtusata, Q. coccolobifolia, Q. sideroxyla) (mixed species), family Fagaceae; broadleaf
- Where: Sierra de Santa Rosa, Guanajuato (bosques de encino). Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#where
- Biomes: temperate
- Stand: natural
- DBH range: 4.8–40.5 cm. Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#dbh
- Height range: 3.55–15.7 m. Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#height
- Method: Additive system of component equations fitted simultaneously (iterated seemingly unrelated regression). Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#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

Cortés-Sánchez, B. G., Ángeles-Pérez, G., De los Santos-Posadas, H. M., & Ramírez-Maldonado, H. (2019). Ecuaciones alométricas para estimar biomasa en especies de encino en Guanajuato, México. Madera y Bosques, 25(2), e2521799.

- DOI: https://doi.org/10.21829/myb.2019.2521799
- Access: open access
- Copy we read: https://myb.ojs.inecol.mx/index.php/myb/article/download/e2521799/1958
- Every equation from this source: https://treeallometry.org/sources/cortes-sanchez-2019/
- Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#source

## The facts, in the source's words

**Equation** (Table 8, Grupo 2):

> Bf = 0.072967 × Dn^2.087881 × At^0.32756

Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#equation

**Our note:** Group sample size not stated; D and H ranges are the union of the three species' Table 1 ranges. Adjusted R2 (not stored): stem 0.90, branches 0.86 (Table 8). Foliage and total of this group not added (see source notes).

## 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 = 15.5, H = 7.2 | 42.6 | 42.6 | Computed from the printed form: computed from the published form (Table 8) |
| D = 29.8, H = 12.1 | 198 | 198 | Computed from the printed form: computed from the published form (Table 8) |

Cite: https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/#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: Cortés-Sánchez, B. G., Ángeles-Pérez, G., De los Santos-Posadas, H. M., & Ramírez-Maldonado, H. (2019). Ecuaciones alométricas para estimar biomasa en especies de encino en Guanajuato, México. Madera y Bosques, 25(2), e2521799. https://doi.org/10.21829/myb.2019.2521799

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Quercus group 2 (obtusata, coccolobifolia, sideroxyla): stem biomass", checked 2026-11-02, https://treeallometry.org/equations/cortes-sanchez-2019-g2-stem/. 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/cortes-sanchez-2019-g2-stem.json
Report a problem: email info@restorationscope.com with the equation id (cortes-sanchez-2019-g2-stem) and where the right value appears.