# Norway spruce, Czech Republic: Stem biomass from D and H/D (Table 2)

Stem biomass equation for Picea abies, Czechia, from Čihák & Vejpustková 2018. 139 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Čihák & Vejpustková 2018 (Table 2 and Eq. 2, p. 113 and p. 110):

> ST = exp(b0 + b1ln(D) + b2ln(H/D))λ; b0 = -3.62155, b1 = 2.84648, b2 = 1.0886, λ = 1.002

Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#equation

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

```
Stem biomass = exp(-3.62155 + 2.84648 * ln(D) + 1.0886 * ln(H/D)) * 1.002
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: exp(-3.62155 + 2.84648 * ln(D) + 1.0886 * ln(H/D)) * 1.002, with D in cm, H in m; output in kg.
Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#canonical

## What it covers

- Output: Stem biomass, kg
- Taxon: Picea abies (species), family Pinaceae; conifer
- Where: 25 stands on 15 sites, Czech Republic (acidic and nutrient-medium sites). Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#where
- Biomes: temperate
- Stand: mixed
- Trees measured: 139. Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#n_trees
- R²: 0.96. Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#r2
- Correction factor: 1.002 (applied). Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#cf
- Method: log-log linear regression with Marklund (1987) back-transformation correction factor. Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#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

Čihák, T., & Vejpustková, M. (2018). Parameterisation of allometric equations for quantifying aboveground biomass of Norway spruce (Picea abies (L.) H. Karst.) in the Czech Republic. Journal of Forest Science, 64(3), 108–117.

- DOI: https://doi.org/10.17221/61/2017-jfs
- Access: open access
- Copy we read: https://www.agriculturejournals.cz/publicFiles/61_2017-JFS.pdf
- Every equation from this source: https://treeallometry.org/sources/cihak-2018/
- Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#source

## The facts, in the source's words

**Equation** (Table 2 and Eq. 2, p. 113 and p. 110):

> ST = exp(b0 + b1ln(D) + b2ln(H/D))λ; b0 = -3.62155, b1 = 2.84648, b2 = 1.0886, λ = 1.002

Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#equation

**Trees measured** (Abstract):

> an extensive data set of 139 spruce trees collected in 25 stands on 15 sites

Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#quote-fit-n-trees

**Our note:** Coefficients, R2 and lambda as printed in Table 2 (lambda per Marklund 1987, Eq. 3, already multiplied in). H/D is slenderness ratio, tree height (m) over DBH (cm). Stem biomass excludes the stump. Not recommended for trees with D < 7 cm. Table 2 also gives models with site index (SI) or tree age (A) and crown biomass models, not added here (no canonical variable for SI or A; crown has no output quantity).

## 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, H = 10 | 18.8 | 18.8 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 25, H = 22 | 222 | 222 | Computed from the printed form: computed from the published form (coefficients as printed) |
| D = 45, H = 30 | 875 | 875 | Computed from the printed form: computed from the published form (coefficients as printed) |

Cite: https://treeallometry.org/equations/cihak-2018-stem-d-hd/#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: Čihák, T., & Vejpustková, M. (2018). Parameterisation of allometric equations for quantifying aboveground biomass of Norway spruce (Picea abies (L.) H. Karst.) in the Czech Republic. Journal of Forest Science, 64(3), 108–117. https://doi.org/10.17221/61/2017-jfs

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Norway spruce, Czech Republic: Stem biomass from D and H/D (Table 2)", checked 2026-11-02, https://treeallometry.org/equations/cihak-2018-stem-d-hd/. 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/cihak-2018-stem-d-hd.json
Report a problem: email info@restorationscope.com with the equation id (cihak-2018-stem-d-hd) and where the right value appears.