# Polylepis racemosa AGB from stem diameter at 50 cm (model 6)

Aboveground biomass equation for Polylepis racemosa, Peru, from Herrera Vásquez 2022. 11 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Herrera Vásquez 2022 (Results, text under Figura 8):

> LnBA=2,394988+0,082807*D50; el que alcanza un R2: 0,932

Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#equation

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

```
Aboveground biomass = exp(2.394988 + 0.082807 * D50)
```

Inputs: D50 = Stem diameter at 50 cm (cm).
The source's own form: exp(2.394988 + 0.082807 * D50), with D50 in cm; output in kg.
Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Polylepis racemosa (species), family Rosaceae; broadleaf
- Where: Relict forest, Bella Andina community, Chota, Cajamarca, Peru. Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#where
- Biomes: tropical, montane
- Stand: natural
- Trees measured: 11. Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#n_trees
- R²: 0.932. Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#r2
- Method: OLS on ln(biomass) vs D50 (model 6 of 10 tested); no correction factor reported. Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#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

Herrera Vásquez, J. W. (2022). Ecuaciones alométricas para estimar biomasa aérea y carbono en Polylepis racemosa en un bosque relicto ubicado en la comunidad de Bella Andina, Chota, Cajamarca. Tesis de Ingeniero Forestal y Ambiental, Universidad Nacional Autónoma de Chota, Peru.

- Link: https://repositorio.unach.edu.pe/items/e9ea63fa-d11a-43dc-865b-b70102fd3bcc
- Access: open access
- Copy we read: https://repositorio.unach.edu.pe/bitstreams/0d193d67-a6a6-402a-be41-faa8932cda9e/download
- Every equation from this source: https://treeallometry.org/sources/herrera-vasquez-2022/
- Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#source

## The facts, in the source's words

**Equation** (Results, text under Figura 8):

> LnBA=2,394988+0,082807*D50; el que alcanza un R2: 0,932

Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#equation

**Trees measured** (Results, before Tabla 2):

> Las medidas dasométricas del diámetro 50 centímetros (D50), altura total (ht), número de ramas (NR) y diámetro de copa (DC) de los 11 árboles de Polylepis racemosa

Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#quote-fit-n-trees

**Note** (Results, after Tabla 2):

> La marca de clase de D50 centímetros (Figura 4), se distribuye desde 7,5 a 36,2

Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#quote-notes

**Our note:** Uses D50, the stem diameter 50 cm above ground (new canonical variable D50, cm), not DBH. Exponential (not power) form: ln(biomass) is linear in D50. Fitted on 11 destructively sampled trees, one per diameter class, D50 7,5–36,2 cm, total height 1,8–7,0 m; samples oven-dried at 105 °C. The listed D50 values of the sampled trees equal the class marks of Tabla 1, so they may be class midpoints rather than measured diameters. Undergraduate thesis, small sample: use with caution.

## 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 |
| --- | --- | --- | --- |
| D50 = 21.6 | 65.6 | 65.6 | Computed from the printed form: computed from the published form; Tabla 3 tree F (D50 21,6 cm) weighed 59,723 kg |
| D50 = 36.2 | 220 | 220 | Computed from the printed form: computed from the published form; Tabla 3 tree K weighed 186,968 kg |

Cite: https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/#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: Herrera Vásquez, J. W. (2022). Ecuaciones alométricas para estimar biomasa aérea y carbono en Polylepis racemosa en un bosque relicto ubicado en la comunidad de Bella Andina, Chota, Cajamarca. Tesis de Ingeniero Forestal y Ambiental, Universidad Nacional Autónoma de Chota, Peru.

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Polylepis racemosa AGB from stem diameter at 50 cm (model 6)", checked 2026-11-01, https://treeallometry.org/equations/herrera-vasquez-2022-polylepis-racemosa/. 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/herrera-vasquez-2022-polylepis-racemosa.json
Report a problem: email info@restorationscope.com with the equation id (herrera-vasquez-2022-polylepis-racemosa) and where the right value appears.