Tree Allometrics

Pseudotsuga menziesii / Aboveground biomass, without leaves

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

Aboveground biomass, without leavesPseudotsuga menziesii · PinaceaeUnited StatesRead from the original paper
Photo of Pseudotsuga menziesii
© Danny Steaven · CC BY-SA · iNaturalist
Equation

As printed (Example 1, p. 11)

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

In this library's units, ready to compute (kg)

Aboveground biomass, without leaves = 0.45359237 * 0.135206506787 * (D/2.54)^1.713527048035 * (H/0.3048)^1.047613377046
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

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).

Source
a Douglas-fir (Pseudotsuga menziesii; SPCD = 202)
Taxon · Example 1, p. 8
growing in the Marine Division (DIVISION = 240)
Where · Example 1, p. 8
yi = a × Di^b × Hi^c + εi
Equation · Eq. 1, p. 2
Di is diameter (inches) at breast height (4.5 feet), Hi is total tree height (feet)
Units · Methods, Model development, p. 2
units for volume and biomass predictions are cubic feet and pounds, respectively
published.output unit · Examples of tree-level calculations, p. 8
total aboveground biomass (without foliage)
output.excludes · Methods, Model development, p. 4
"Total Tree Wood+Bark","TT_WDBK_DW_ADJ","202","240","MARINE_DIVISION",61,14.227868852459,3.6,44.9
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
key modeling statistics such as sample sizes (n), tree diameter distributions (minimum, mean, and maximum)
Fit · Methods, Model development, p. 6
Trees measured
61
DBH range
9.14–114.05 cm
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
Where
FIA ecodivision Marine Division (240), mapped in GTR fig. 1
Last checked
2026-11-03
Calculate
Height from
1,431
Aboveground biomass, without leaves (kg)
673
Carbon (kg), ×0.47
2,466
CO₂e (kg), ×44/12
Fitted DBH range01,0002,0003,0004,0005,00020406080100DBH (cm)Aboveground biomass, without leaves (kg)Aboveground biomass, without leaves

Shaded: the DBH range the model was fitted on. Other inputs held at the values above.

Checks this equation passes

On every build, the library's form and the paper's own form (in its units) must both give these values within 1%.

InputsExpectedWe getFrom
D = 50.8, H = 33.51,4311,431Value 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

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