# Pinus caribaea trunk (stem with bark) biomass from DBH, height and wood density (simultaneous fit)

Stem biomass equation for Pinus caribaea var. hondurensis, Brazil, from Coutinho et al. 2018. 20 trees, DBH 8.2–23.7 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Coutinho et al. 2018 (Table 5):

> bstrunk = β0+β1DBH+β2ht+β3ρ: -41.5, 1.760, 1.374, 39.377

Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#equation

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

```
Stem biomass = -41.5 + 1.760*D + 1.374*H + 39.377*rho
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m); rho = Wood density (oven-dry mass / green volume) (g/cm³).
The source's own form: -41.5 + 1.760*DBH + 1.374*ht + 39.377*rho, with DBH in cm, ht in m, rho in g/cm3; output in kg.
Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#canonical

## What it covers

- Output: Stem biomass, kg
- Taxon: Pinus caribaea var. hondurensis (species), family Pinaceae; conifer
- Where: Experimental area of UESB, Vitória da Conquista, Bahia. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#where
- Biomes: tropical, subtropical
- Stand: plantation
- Trees measured: 20. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#n_trees
- DBH range: 8.2–23.7 cm. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#dbh
- Height range: 6.4–14.2 m. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#height
- R²: 0.84. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#r2
- Method: Simultaneous (SUR) linear regression ensuring additivity; R2 reported is adjusted R2. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#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

Coutinho, V. M., Sanquetta, C. R., Bittencourt, P. A., Silva, S. A., Proceke, K. H., Delarrmelina, W. M., & Moreau, J. (2018). Simultaneous Equations to Estimate Aboveground Biomass of Pinus caribaea var. hondurensis. Floresta e Ambiente, 25(3), e20160452.

- DOI: https://doi.org/10.1590/2179-8087.045216
- Access: open access
- Copy we read: http://www.scielo.br/pdf/floram/v25n3/2179-8087-floram-25-3-e20160452.pdf
- Every equation from this source: https://treeallometry.org/sources/coutinho-2018/
- Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#source

## The facts, in the source's words

**Equation** (Table 5):

> bstrunk = β0+β1DBH+β2ht+β3ρ: -41.5, 1.760, 1.374, 39.377

Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#equation

**Trees measured** (Abstract):

> Twenty (20) trees from the experimental area of the State University of Southwest Bahia (UESB), Vitória da Conquista, Bahia, Brazil, were measured and weighed

Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#quote-fit-n-trees

**Smallest DBH** (Section 3 (Results)):

> with a minimum value of 8.20 cm and a maximum of 23.70 cm; average total height of 11.06 m, ranging from 6.40 m to 14.20 m

Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#quote-fit-dbh-min-cm

**R²** (Table 5):

> R2adj 0.84

Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#quote-fit-r2

**Our note:** Ten-year-old plantation, 3 m x 3 m spacing, 20 trees. The paper writes the height symbol as ht in this row (TH elsewhere) and gives wood density rho in g/cm3 (stand mean 0.44). Trunk is with bark. Fitted simultaneously (Table 5).

## 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 = 12, H = 9, rho = 0.44 | 9.31 | 9.31 | Computed from the printed form: computed from the published form |
| D = 20, H = 13, rho = 0.5 | 31.3 | 31.3 | Computed from the printed form: computed from the published form |

Cite: https://treeallometry.org/equations/coutinho-2018-trunk-sur/#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: Coutinho, V. M., Sanquetta, C. R., Bittencourt, P. A., Silva, S. A., Proceke, K. H., Delarrmelina, W. M., & Moreau, J. (2018). Simultaneous Equations to Estimate Aboveground Biomass of Pinus caribaea var. hondurensis. Floresta e Ambiente, 25(3), e20160452. https://doi.org/10.1590/2179-8087.045216

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Pinus caribaea trunk (stem with bark) biomass from DBH, height and wood density (simultaneous fit)", checked 2026-11-02, https://treeallometry.org/equations/coutinho-2018-trunk-sur/. 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/coutinho-2018-trunk-sur.json
Report a problem: email info@restorationscope.com with the equation id (coutinho-2018-trunk-sur) and where the right value appears.