# Sambucus racemosa, belowground dry mass vs base diameter (Model 1)

Root biomass equation for Sambucus racemosa, Russia, from Kartashova et al. 2026. 7 trees. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Kartashova et al. 2026 (Eq. (1)/(2) and Table 2 (p. 10-11)):

> lnPbg = a0 + a1lnD0; Sambucus racemosa: a0 = -3,075, a1 = 3,786, BaskCF = 2,32

Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#equation

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

```
Root biomass = 2.32 * exp(-3.075 + 3.786 * ln(DRC))
```

Inputs: DRC = Root collar / stem base diameter (cm).
The source's own form: 2.32 * exp(-3.075 + 3.786 * ln(D0)), with D0 in cm; output in kg.
Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#canonical

## What it covers

- Output: Root biomass, kg
- Taxon: Sambucus racemosa (species), family Sambucaceae; shrub
- Where: Prigorodnoye Forestry, Levoberezhnoe District Forestry, Voronezh Oblast (pine stands, forest-steppe). Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#where
- Biomes: temperate
- Stand: natural
- Trees measured: 7. Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#n_trees
- R²: 0.814. Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#r2
- Correction factor: 2.32 (applied). Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#cf
- Method: log-log regression (OLS on natural logs), Baskerville correction factor. Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#method
- Verification: read in the original source
- Last checked: 2026-11-01. Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#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

Kartashova, N.P., Sheshnitsan, S.S., Tsaregorodtsev, A.V. (2026). Allometric models of biomass of understory trees and shrubs in pine stands of Voronezh Oblast. Forestry Engineering Journal (Lesotekhnicheskii zhurnal), 16(3), 6–19.

- DOI: https://doi.org/10.34220/issn.2222-7962/2026.3/1
- Access: open access
- Copy we read: http://lestehjournal.ru/sites/default/files/journal_pdf/1._6-19_ltzh_2026_tom_16_no_3_63.pdf
- Every equation from this source: https://treeallometry.org/sources/kartashova-2026/
- Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#source

## The facts, in the source's words

**Equation** (Eq. (1)/(2) and Table 2 (p. 10-11)):

> lnPbg = a0 + a1lnD0; Sambucus racemosa: a0 = -3,075, a1 = 3,786, BaskCF = 2,32

Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#equation

**Trees measured** (Table 1, p. 9):

> Sambucus racemosa n = 7

Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#quote-fit-n-trees

**Our note:** Understory plant (small tree/shrub) under Scots pine. Output in kg: the text states kg for P; Table 1 headings say g, but the kg reading matches the ranges in Table 1 (e.g. Sambucus Pag max 943 g = 0.943 kg). Predictor is base diameter D0 (root collar), mapped to canonical DRC. n=7 (<10): authors treat as preliminary. Best-supported species in the paper (Q2CV 0.53-0.86).

## 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 |
| --- | --- | --- | --- |
| DRC = 0.5 | 0.00777 | 0.00777 | Computed from the printed form: hand-computed from the published form (Table 2 coefficients, Baskerville factor BaskCF applied) |
| DRC = 1 | 0.107 | 0.107 | Computed from the printed form: hand-computed from the published form (Table 2 coefficients, Baskerville factor BaskCF applied) |
| DRC = 1.5 | 0.497 | 0.497 | Computed from the printed form: hand-computed from the published form (Table 2 coefficients, Baskerville factor BaskCF applied) |

Cite: https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/#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: Kartashova, N.P., Sheshnitsan, S.S., Tsaregorodtsev, A.V. (2026). Allometric models of biomass of understory trees and shrubs in pine stands of Voronezh Oblast. Forestry Engineering Journal (Lesotekhnicheskii zhurnal), 16(3), 6–19. https://doi.org/10.34220/issn.2222-7962/2026.3/1

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Sambucus racemosa, belowground dry mass vs base diameter (Model 1)", checked 2026-11-01, https://treeallometry.org/equations/kartashova-2026-sambucus-pbg-d0/. 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/kartashova-2026-sambucus-pbg-d0.json
Report a problem: email info@restorationscope.com with the equation id (kartashova-2026-sambucus-pbg-d0) and where the right value appears.