# NSVB Douglas-fir, Marine Division (240): total aboveground biomass, Schumacher-Hall model (Eq. 1)

Aboveground biomass equation (without leaves) for Pseudotsuga menziesii, United States, from Westfall et al. 2024. 61 trees, DBH 9.14–114.05 cm. Listed on Tree Allometrics, a free library of tree allometric equations, each quoted from the source that published it.

## Equation

As printed in Westfall et al. 2024 (Example 1, p. 11):

> AGBPredicted = 0.135206506787 × 20^1.713527048035 × 110^1.047613377046 = 3154.5539926725

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#equation

In this library's units, ready to compute (aboveground biomass, without leaves in kg):

```
Aboveground biomass, without leaves = 0.45359237 * 0.135206506787 * (D/2.54)^1.713527048035 * (H/0.3048)^1.047613377046
```

Inputs: D = Diameter at breast height (1.3 m) (cm); H = Total tree height (m).
The source's own form: 0.135206506787 * DBH^1.713527048035 * HT^1.047613377046, with DBH in in, HT in ft; output in lb.
Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#canonical

This total leaves out leaves (foliage), as the source defines it.

## What it covers

- Output: Aboveground biomass, without leaves, kg
- Taxon: Pseudotsuga menziesii (species), family Pinaceae; conifer
- Where: FIA ecodivision Marine Division (240), mapped in GTR fig. 1. Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#where
- Biomes: temperate
- Stand: not stated
- Trees measured: 61. Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#n_trees
- DBH range: 9.14–114.05 cm. Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#dbh
- Method: NSVB Schumacher-Hall model (Eq. 1), coefficients for SPCD 202 in DIVISION 240 from table S8a (the total aboveground biomass table used in Example 1); fitted with weighted regression to destructively sampled trees. Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#method
- Verification: read in the original source
- Last checked: 2026-11-03. Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#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

Westfall, J.A., Coulston, J.W., Gray, A.N., Shaw, J.D., Radtke, P.J., Walker, D.M., Weiskittel, A.R., et al. (2024). A national-scale tree volume, biomass, and carbon modeling system for the United States. Gen. Tech. Rep. WO-104. Washington, DC: USDA Forest Service. 37 p.

- DOI: https://doi.org/10.2737/WO-GTR-104
- Access: open access
- Copy we read: https://research.fs.usda.gov/download/treesearch/66998.pdf
- Every equation from this source: https://treeallometry.org/sources/westfall-2024/
- Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#source

## The facts, in the source's words

**Equation** (Example 1, p. 11):

> AGBPredicted = 0.135206506787 × 20^1.713527048035 × 110^1.047613377046 = 3154.5539926725

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#equation

**Taxon** (Example 1, p. 8):

> a Douglas-fir (Pseudotsuga menziesii; SPCD = 202)

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-taxon

**Where** (Example 1, p. 8):

> growing in the Marine Division (DIVISION = 240)

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-region

**Equation** (Eq. 1, p. 2):

> yi = a × Di^b × Hi^c + εi

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-expression

**Units** (Methods, Model development, p. 2):

> Di is diameter (inches) at breast height (4.5 feet), Hi is total tree height (feet)

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-published-units

**published.output unit** (Examples of tree-level calculations, p. 8):

> units for volume and biomass predictions are cubic feet and pounds, respectively

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-published-output-unit

**output.excludes** (Methods, Model development, p. 4):

> total aboveground biomass (without foliage)

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-output-excludes

**Fit** (Table S19_component_division_spcd_scorecard.csv (WO-GTR-104-Supp1), columns VAR2,VAR3,SPCD,DIVISION,DIVISION_DESCRIPTION,N,Avg_DBH,Min_DBH,Max_DBH):

> "Total Tree Wood+Bark","TT_WDBK_DW_ADJ","202","240","MARINE_DIVISION",61,14.227868852459,3.6,44.9

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-fit

**Fit** (Methods, Model development, p. 6):

> key modeling statistics such as sample sizes (n), tree diameter distributions (minimum, mean, and maximum)

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#quote-fit-2

**Our note:** Output is gross AGB without foliage (AGBPredicted), before NSVB's cull and broken-top reductions. Coefficients for Douglas-fir in the Marine Division (240) only; NSVB uses other coefficients for Douglas-fir elsewhere (tables S1a–S9a). Paper units: in, ft, lb; expression converts D cm→in (/2.54), H m→ft (/0.3048) and lb→kg (×0.45359237). n and the DBH range are from the scorecard for TT_WDBK_DW_ADJ in 240 (table S19). For AGB the scorecard rates NSVB's harmonized total (TT_WDBK_DW_ADJ), not this model alone; only its n and DBH range are used. DBH is measured at 4.5 ft (1.37 m).

## 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 = 50.8, H = 33.528 | 1,431 | 1,431 | Value printed in the paper: Example 1 (p. 11) prints 3154.5539926725 lb for D = 20 in, H = 110 ft; inputs and expected converted to cm, m, kg |

Cite: https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/#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: Westfall, J.A., Coulston, J.W., Gray, A.N., Shaw, J.D., Radtke, P.J., Walker, D.M., Weiskittel, A.R., et al. (2024). A national-scale tree volume, biomass, and carbon modeling system for the United States. Gen. Tech. Rep. WO-104. Washington, DC: USDA Forest Service. 37 p. https://doi.org/10.2737/WO-GTR-104

Cite this page for the record and checks: Tree Allometrics (Restoration Scope), "NSVB Douglas-fir, Marine Division (240): total aboveground biomass, Schumacher-Hall model (Eq. 1)", checked 2026-11-03, https://treeallometry.org/equations/westfall-2024-pseudotsuga-menziesii-240-agb/. 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/westfall-2024-pseudotsuga-menziesii-240-agb.json
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