# Diostea juncea aboveground dry weight from DAP (Cuadro 2)

Aboveground biomass equation for Diostea juncea, Argentina, from Gyenge et al. 2009. 10 trees, DBH 5.5–15.2 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Gyenge et al. 2009 (Cuadro 2, Diostea juncea column, T row (DAP), p. 98):

> T –25,556 + 4,428 * DAP

Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#equation

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

```
Aboveground biomass = -25.556 + 4.428 * D
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: -25.556 + 4.428 * DAP, with DAP in cm; output in kg.
Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Diostea juncea (species), family Verbenaceae; broadleaf
- Where: Foyel river valley, Río Negro, NW Patagonia, Argentina. Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#where
- Biomes: temperate, montane
- Stand: natural
- Trees measured: 10. Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#n_trees
- DBH range: 5.5–15.2 cm. Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#dbh
- Method: stepwise linear regression of tree dry weight on DAP (adjusted R² 0,79). Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#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

Gyenge, J., Fernández, M. E., Sarasola, M., de Urquiza, M., & Schlichter, T. (2009). Ecuaciones para la estimación de biomasa aérea y volumen de fuste de algunas especies leñosas nativas en el valle del río Foyel, NO de la Patagonia argentina. Bosque, 30(2), 95-101.

- DOI: https://doi.org/10.4067/s0717-92002009000200005
- Access: open access
- Copy we read: http://www.scielo.cl/pdf/bosque/v30n2/art05.pdf
- Every equation from this source: https://treeallometry.org/sources/gyenge-2009/
- Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#source

## The facts, in the source's words

**Equation** (Cuadro 2, Diostea juncea column, T row (DAP), p. 98):

> T –25,556 + 4,428 * DAP

Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#equation

**Trees measured** (Cuadro 2, R² aj. and n columns, p. 98):

> T –25,556 + 4,428 * DAP 0,79 10

Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#quote-fit-n-trees

**Smallest DBH** (Métodos, p. 97):

> La distribución de DAP de los árboles apeados fue de: retamo 5,5 a 15,2 cm

Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#quote-fit-dbh-min-cm

**Our note:** Total aboveground dry weight (T, kg) is the sum of leaves, thin and thick branches and stem, built branch by branch. Adjusted R² 0,79 is printed as R² aj.; the schema field r2 is left out because the paper gives only the adjusted value. No correction factor applies (linear model). The same table gives a basal-diameter (DB, measured at 15 cm above ground) equation, not added because DB at 15 cm is not a canonical variable. Stem dry weight (F) rows are credited to Gyenge et al. (2008) and the DAP volume rows to Reque et al. (2007), so they are not taken from this paper.

## 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 | 9.87 | 9.87 | Computed from the printed form: hand-computed from the Cuadro form |
| D = 14 | 36.4 | 36.4 | Computed from the printed form: hand-computed from the Cuadro form |

Cite: https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/#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: Gyenge, J., Fernández, M. E., Sarasola, M., de Urquiza, M., & Schlichter, T. (2009). Ecuaciones para la estimación de biomasa aérea y volumen de fuste de algunas especies leñosas nativas en el valle del río Foyel, NO de la Patagonia argentina. Bosque, 30(2), 95-101. https://doi.org/10.4067/s0717-92002009000200005

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Diostea juncea aboveground dry weight from DAP (Cuadro 2)", checked 2026-11-02, https://treeallometry.org/equations/gyenge-2009-agb-retamo-dap/. 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/gyenge-2009-agb-retamo-dap.json
Report a problem: email info@restorationscope.com with the equation id (gyenge-2009-agb-retamo-dap) and where the right value appears.