# Birch aboveground biomass, young dense stands, N Sweden (Table 5)

Aboveground biomass equation for Betula, Sweden, from Repola & Ahnlund Ulvcrona 2014. 86 trees, DBH 1–11 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Repola & Ahnlund Ulvcrona 2014 (Table 5, p. 12):

> Total above-ground, kg, birch: Intercept −4.074; dbh/(dbh + n) 7.970; h/(h + m) 16.922; ln(h) −3.210; n 3; m 10; var(uk) 0.002; var(eki) 0.018

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#equation

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

```
Aboveground biomass = exp(-4.074 + (0.002 + 0.018) / 2 + 7.970 * D / (D + 3) + (16.922) * H / (H + 10) + (-3.210) * ln(H))
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: exp(-4.074 + (0.002 + 0.018) / 2 + 7.970 * dbh / (dbh + 3) + (16.922) * h / (h + 10) + (-3.210) * ln(h)), with dbh in cm, h in m; output in kg.
Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Betula (genus), family Betulaceae; broadleaf
- Where: Six young, dense, naturally regenerated stands in northern Sweden (63.26-65.69 N). Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#where
- Biomes: boreal
- Stand: natural
- Trees measured: 86. Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#n_trees
- DBH range: 1–11 cm. Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#dbh
- Height range: 1.8–8.6 m. Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#height
- Method: linear mixed model of ln(biomass) with random stand effect; ln(y) = Intercept + b1 dbh/(dbh + n) + b2 h/(h + m) + b3 ln(h). Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#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

Repola, J., Ahnlund Ulvcrona, K. (2014). Modelling biomass of young and dense Scots pine (Pinus sylvestris L.) dominated mixed forests in northern Sweden. Silva Fennica, 48(5), 1190.

- DOI: https://doi.org/10.14214/sf.1190
- Access: open access
- Copy we read: https://silvafennica.fi/pdf/1190
- Every equation from this source: https://treeallometry.org/sources/repola-2014/
- Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#source

## The facts, in the source's words

**Equation** (Table 5, p. 12):

> Total above-ground, kg, birch: Intercept −4.074; dbh/(dbh + n) 7.970; h/(h + m) 16.922; ln(h) −3.210; n 3; m 10; var(uk) 0.002; var(eki) 0.018

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#equation

**Equation** (Section 2.6, p. 10):

> a variance correction term, ((var(uk) + var(eki))/2) should be added to the intercept to correct for bias due to the logarithmic transformation

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#quote-expression

**Trees measured** (Section 2.4, p. 6):

> In total, 280 trees were included in this destructive aboveground biomass study, of which 126 were pine, 68 spruce and 86 birch.

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#quote-fit-n-trees

**Largest DBH** (Section 2.4, p. 6):

> The range of dbh was 1–22 cm, 1–21 cm and 1–11 cm for pine, spruce and birch, respectively

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#quote-fit-dbh-max-cm

**h max m** (Section 2.4, p. 6):

> The range of heights was 1.7–11.7 m, 1.6–13.3 m and 1.8–8.6 m for pine, spruce and birch, respectively

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#quote-fit-h-max-m

**Our note:** Fitted on pine-dominated mixed stands; fit n, DBH and height ranges are the species sample ranges. Expression applies the paper's stated additive correction (var(uk) + var(eki))/2 to the intercept. Variance values are as printed in Table 5; no other correction factor is stated. The paper models the total independently of the components, so it need not equal their sum. Birch coefficients are for Betula pendula and B. pubescens pooled. 

## 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 = 5, H = 5 | 4.02 | 4.02 | Computed from the printed form: hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction |
| D = 10, H = 8 | 18.4 | 18.4 | Computed from the printed form: hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction |

Cite: https://treeallometry.org/equations/repola-2014-agb-birch/#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: Repola, J., Ahnlund Ulvcrona, K. (2014). Modelling biomass of young and dense Scots pine (Pinus sylvestris L.) dominated mixed forests in northern Sweden. Silva Fennica, 48(5), 1190. https://doi.org/10.14214/sf.1190

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Birch aboveground biomass, young dense stands, N Sweden (Table 5)", checked 2026-11-02, https://treeallometry.org/equations/repola-2014-agb-birch/. 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/repola-2014-agb-birch.json
Report a problem: email info@restorationscope.com with the equation id (repola-2014-agb-birch) and where the right value appears.