# Eucalyptus globulus branch (>4 cm) dry weight (Cuadro 2)

Branch biomass equation for Eucalyptus globulus subsp. globulus, Chile, from Prado Donoso & Alarcón Maya 1991. 41 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Prado Donoso & Alarcón Maya 1991 (Cuadro 2, RAMAS (> 4cm) row, p. 64):

> PRAM = 17,912236 - 3,17988 D + 0,00316 (D²H)

Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#equation

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

```
Branch biomass = 17.912236 - 3.17988 * D + 0.00316 * (D^2 * H)
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: 17.912236 - 3.17988 * DAP + 0.00316 * (DAP^2 * H), with DAP in cm, H in m; output in kg.
Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#canonical

## What it covers

- Output: Branch biomass, kg
- Taxon: Eucalyptus globulus subsp. globulus (species), family Myrtaceae; broadleaf
- Where: Coastal zone of Valparaíso Region (Longotoma, Peñuelas, Santa Marta), central Chile. Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#where
- Biomes: temperate
- Stand: plantation
- Trees measured: 41. Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#n_trees
- R²: 0.73. Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#r2
- Method: stepwise linear regression on dry weight (Cuadro 2). Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#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

Prado Donoso, J. A., & Alarcón Maya, C. (1991). Funciones de biomasa de Eucalyptus globulus ssp. globulus en la región costera central. Ciencia e Investigación Forestal, 5(1).

- DOI: https://doi.org/10.52904/0718-4646.1991.147
- Access: open access
- Copy we read: https://revista.infor.cl/index.php/infor/article/download/147/140
- Every equation from this source: https://treeallometry.org/sources/prado-1991/
- Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#source

## The facts, in the source's words

**Equation** (Cuadro 2, RAMAS (> 4cm) row, p. 64):

> PRAM = 17,912236 - 3,17988 D + 0,00316 (D²H)

Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#equation

**Trees measured** (Metodos, Muestreo, p. 60):

> se utilizó una muestra de 41 árboles extraídos de tres parcelas

Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#quote-fit-n-trees

**R²** (Cuadro 2, R² column, p. 64):

> RAMAS (> 4cm) ... 0,73

Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#quote-fit-r2

**Our note:** Branches thicker than 4 cm only (twigs and leaves are separate components). Very imprecise: the authors report a 89.7% mean square error and advise taking branches by difference. Trees from three unmanaged 20-25 year old coppice-origin (monte alto) stands. The paper does not print DBH or height ranges of the fitted sample, only a table of diameter classes, so none is given. H is read as total height (HTOT): the paper's own stand-table comparison feeds DAP and HT into these functions. No correction factor is stated for the log models, so none applies here. Not additive with the other component functions, as the authors note.

## 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, H = 20 | -20.4 | -20.4 | Computed from the printed form: hand-computed from the Cuadro 2 form |
| D = 35, H = 25 | 3.39 | 3.39 | Computed from the printed form: hand-computed from the Cuadro 2 form |

Cite: https://treeallometry.org/equations/prado-1991-branches-d-d2h/#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: Prado Donoso, J. A., & Alarcón Maya, C. (1991). Funciones de biomasa de Eucalyptus globulus ssp. globulus en la región costera central. Ciencia e Investigación Forestal, 5(1). https://doi.org/10.52904/0718-4646.1991.147

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Eucalyptus globulus branch (>4 cm) dry weight (Cuadro 2)", checked 2026-11-02, https://treeallometry.org/equations/prado-1991-branches-d-d2h/. 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/prado-1991-branches-d-d2h.json
Report a problem: email info@restorationscope.com with the equation id (prado-1991-branches-d-d2h) and where the right value appears.