# Mountain hemlock total aboveground biomass from DBH (Table 4)

Aboveground biomass equation for Tsuga mertensiana, United States, from Poudel et al. 2019. 9 trees, DBH 13.5–76.2 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Poudel et al. 2019 (Table 4, species row and table note):

> Mountain hemlock  a, b, c, d, CF: −0.9861  2.0975  CF 1.0000; model form exp(a + bX1)

Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#equation

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

```
Aboveground biomass = exp(-0.9861 + 2.0975 * ln(D))
```

Inputs: D = Diameter at breast height (1.3 m) (cm).
The source's own form: exp(-0.9861 + 2.0975 * ln(DBH)), with DBH in cm; output in kg.
Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#canonical

## What it covers

- Output: Aboveground biomass, kg
- Taxon: Tsuga mertensiana (species), family Pinaceae; conifer
- Where: Western U.S.A., legacy destructive-sampling biomass collection (Radtke et al. 2015). Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#where
- Biomes: temperate
- Stand: mixed
- Trees measured: 9. Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#n_trees
- DBH range: 13.5–76.2 cm. Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#dbh
- Height range: 6.1–37.2 m. Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#height
- Method: nonlinear regression, response not log-transformed (CF = 1.0000). Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#method
- Verification: read in the original source
- Last checked: 2026-11-02. Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#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

Poudel, K. P., Temesgen, H., Radtke, P. J., & Gray, A. N. (2019). Estimating individual-tree aboveground biomass of tree species in the western U.S.A. Canadian Journal of Forest Research, 49(6), 701-714.

- DOI: https://doi.org/10.1139/cjfr-2018-0361
- Access: open access
- Copy we read: https://vtechworks.lib.vt.edu/bitstreams/13666b54-8fb3-444c-8f8f-f54bc602a4b9/download
- Every equation from this source: https://treeallometry.org/sources/poudel-2019/
- Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#source

## The facts, in the source's words

**Equation** (Table 4, species row and table note):

> Mountain hemlock  a, b, c, d, CF: −0.9861  2.0975  CF 1.0000; model form exp(a + bX1)

Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#equation

**Trees measured** (Table 1):

> Mountain hemlock ... n 9

Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#quote-fit-n-trees

**Smallest DBH** (Table 1):

> Mountain hemlock DBH min 13.5 max 76.2; HT min 6.1 max 37.2

Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#quote-fit-dbh-min-cm

**Our note:** AGB is total aboveground live-tree biomass (stem, bark, branches, foliage). X1 = ln(DBH), X2 = ln(HT), DBH in cm and HT in m. Species identified from the common name in Table 4 (scientific name added from the standard species symbol). Stand type is not stated. Observed ranges in Table 1 cover all trees of the species used.

## 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 = 15 | 109 | 109 | Computed from the printed form: computed from the Table 4 coefficients |
| D = 35 | 646 | 646 | Computed from the printed form: computed from the Table 4 coefficients |

Cite: https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/#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: Poudel, K. P., Temesgen, H., Radtke, P. J., & Gray, A. N. (2019). Estimating individual-tree aboveground biomass of tree species in the western U.S.A. Canadian Journal of Forest Research, 49(6), 701-714. https://doi.org/10.1139/cjfr-2018-0361

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "Mountain hemlock total aboveground biomass from DBH (Table 4)", checked 2026-11-02, https://treeallometry.org/equations/poudel-2019-tsuga-mertensiana/. 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/poudel-2019-tsuga-mertensiana.json
Report a problem: email info@restorationscope.com with the equation id (poudel-2019-tsuga-mertensiana) and where the right value appears.