# Scots pine branch biomass, ln-ln OLS (D only)

Branch biomass equation for Pinus sylvestris, Mongolia, from Tungalag et al. 2020. 35 trees, DBH 4.7–55 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Tungalag et al. 2020 (Table 4, branch section, Eq. 4, type N, p. 17):

> lnŶ=lna+blnD; N: lna = -5.918, b = 2.882, CF = 1.181

Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#equation

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

```
Branch biomass = 1.181 * exp(-5.918 + 2.882 * ln(D))
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: 1.181 * exp(-5.918 + 2.882 * ln(D)), with D in cm; output in kg.
Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#canonical

## What it covers

- Output: Branch biomass, kg
- Taxon: Pinus sylvestris (species), family Pinaceae; conifer
- Where: Northeastern Khangai and western Khentii forest regions, northern Mongolia. Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#where
- Biomes: boreal, montane
- Stand: natural
- Trees measured: 35. Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#n_trees
- DBH range: 4.7–55 cm. Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#dbh
- Height range: 4.6–23 m. Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#height
- Correction factor: 1.181 (applied). Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#cf
- Method: ordinary least squares on ln-transformed data (type N), with correction factor CF = exp(RMSE²/2). Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#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

Tungalag, M., Altanzagas, B., Gerelbaatar, S., & Dorjsuren, Ch. (2020). Tree-level above-ground biomass equations for Pinus sylvestris L. in Mongolia. Mongolian Journal of Biological Sciences, 18(1), 13-21.

- DOI: https://doi.org/10.22353/mjbs.2020.18.02
- Access: open access
- Copy we read: https://www.biotaxa.org/mjbs/article/download/59351/59360 (Wayback Machine copy)
- Every equation from this source: https://treeallometry.org/sources/tungalag-2020/
- Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#source

## The facts, in the source's words

**Equation** (Table 4, branch section, Eq. 4, type N, p. 17):

> lnŶ=lna+blnD; N: lna = -5.918, b = 2.882, CF = 1.181

Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#equation

**Trees measured** (Materials and Methods, Data collection, p. 14):

> A total of 35 sample trees were destructively sampled

Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#quote-fit-n-trees

**Our note:** Ordinary least squares (type N) rows of Table 4 with the printed CF applied; the weighted (type W) rows are not included because their printed RMSE/CF are on a weighted scale. The paper does not say whether the printed lna values for type N are rounded further. Table 4 decimal commas read as decimal points. The abstract names the D and H form (Eq. 6) as the best-fitting; the D-only form is also given. Total AGB = stem + branches + needles; the paper also describes a one-step proportional weighting for additivity, not applied here. Biomass in kg (Eq. 1 text).

## 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 = 10 | 2.42 | 2.42 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 25 | 34 | 34 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 45 | 185 | 185 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/tungalag-2020-branch-d/#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: Tungalag, M., Altanzagas, B., Gerelbaatar, S., & Dorjsuren, Ch. (2020). Tree-level above-ground biomass equations for Pinus sylvestris L. in Mongolia. Mongolian Journal of Biological Sciences, 18(1), 13-21. https://doi.org/10.22353/mjbs.2020.18.02

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Scots pine branch biomass, ln-ln OLS (D only)", checked 2026-11-02, https://treeallometry.org/equations/tungalag-2020-branch-d/. 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/tungalag-2020-branch-d.json
Report a problem: email info@restorationscope.com with the equation id (tungalag-2020-branch-d) and where the right value appears.