# Vochysia guatemalensis plantations, total tree biomass incl. roots (Bt)

Total biomass equation for Vochysia guatemalensis, Costa Rica, from Fonseca G. et al. 2009. 51 trees, DBH 0.5–40.5 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Fonseca G. et al. 2009 (Cuadro 2, Vochysia guatemalensis (R2aj %, SEE, IF, n, FC)):

> Bt = exp(-1,44742 + 1,3308* d ^0,5) 97,98 0,3682 – 51 1,07

Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#equation

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

```
Total biomass = 1.07 * exp(-1.44742 + 1.3308 * D^0.5)
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 1.07 * exp(-1.44742 + 1.3308 * d^0.5), with d in cm; output in kg.
Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#canonical

## What it covers

- Output: Total biomass, kg
- Taxon: Vochysia guatemalensis (species), family Vochysiaceae; broadleaf
- Where: Caribbean (Atlantic) lowlands of Costa Rica. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#where
- Biomes: tropical
- Stand: plantation
- Trees measured: 51. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#n_trees
- DBH range: 0.5–40.5 cm. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#dbh
- R²: 0.9798. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#r2
- Residual SE: 0.3682. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#rse
- Correction factor: 1.07 (applied). Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#cf
- Method: OLS on ln(Bt) vs √d (Statgraphics); Sprugel correction factor. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#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

Fonseca G., W., Alice G., F., & Rey B., J. M. (2009). Modelos para estimar la biomasa de especies nativas en plantaciones y bosques secundarios en la zona Caribe de Costa Rica. Bosque (Valdivia), 30(1), 36–47.

- DOI: https://doi.org/10.4067/S0717-92002009000100006
- Access: open access
- Copy we read: https://www.scielo.cl/pdf/bosque/v30n1/art06.pdf
- Every equation from this source: https://treeallometry.org/sources/fonseca-2009/
- Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#source

## The facts, in the source's words

**Equation** (Cuadro 2, Vochysia guatemalensis (R2aj %, SEE, IF, n, FC)):

> Bt = exp(-1,44742 + 1,3308* d ^0,5) 97,98 0,3682 – 51 1,07

Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#equation

**Smallest DBH** (Métodos, p. 37):

> en V. guatemalensis la muestra fue de 54 individuos con diámetros entre 0,5 y 40,5 cm

Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#quote-fit-dbh-min-cm

**Correction factor** (Métodos, p. 39):

> Los modelos seleccionados con transformaciones logarítmicas fueron corregidos utilizando un factor de corrección (FC)

Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#quote-fit-cf

**Output** (Resultados, p. 39):

> biomasa total (Bt), que incluye todos los componentes del árbol

Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#quote-output-quantity

**Our note:** Bt is whole-tree dry biomass including excavated roots (kg/tree), so the output is total (above + below) biomass, not AGB. FC = 1,07 (exp(SEE²/2)) is printed in its own column and multiplied in here. One mean-diameter tree harvested per plot, plantations 0,5–16 years old; r2 is adjusted R². Diameter range is for the 54 sampled trees; the Bt model used n = 51.

## 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 = 20 | 96.7 | 96.7 | Computed from the printed form: computed from the Cuadro 2 model times FC 1,07 |

Cite: https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/#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: Fonseca G., W., Alice G., F., & Rey B., J. M. (2009). Modelos para estimar la biomasa de especies nativas en plantaciones y bosques secundarios en la zona Caribe de Costa Rica. Bosque (Valdivia), 30(1), 36–47. https://doi.org/10.4067/S0717-92002009000100006

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Vochysia guatemalensis plantations, total tree biomass incl. roots (Bt)", checked 2026-11-01, https://treeallometry.org/equations/fonseca-2009-vochysia-guatemalensis-total/. 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/fonseca-2009-vochysia-guatemalensis-total.json
Report a problem: email info@restorationscope.com with the equation id (fonseca-2009-vochysia-guatemalensis-total) and where the right value appears.