Tree Allometrics

Pseudotsuga menziesii / Foliage biomass

NSVB Douglas-fir, Marine Division (240): total foliage biomass, segmented model (Eq. 2), D ≥ 9 in (22.86 cm)

Foliage biomassPseudotsuga menziesii · PinaceaeUnited StatesRead from the original paper
Photo of Pseudotsuga menziesii
© Danny Steaven · CC BY-SA · iNaturalist
Equation

As printed (Example 1, p. 11)

Wfoliage = 0.477184595914 × 9^(2.592670351881 – 1.249237428914) × 20^1.249237428914 × 110^-0.325050455055 = 83.634788855934

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

Foliage biomass = 0.45359237 * 0.477184595914 * 9^(2.592670351881 - 1.249237428914) * (D/2.54)^1.249237428914 * (H/0.3048)^-0.325050455055
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Output is total foliage dry weight (Wfoliage); NSVB keeps foliage out of total AGB. Coefficients for Douglas-fir in the Marine Division (240) only; NSVB uses other coefficients for Douglas-fir elsewhere (tables S1a–S9a). Upper branch of the segmented model; pair with westfall-2024-pseudotsuga-menziesii-240-foliage-small. 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 FOL_DW in 240 (table S19), which covers the whole segmented model; this record's DBH limit at k is the segmentation point. 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 × k^(b−b1) × Di^b1 × Hi^c + εi; Di ≥ k
Equation · Eq. 2, p. 2
k is a set segmentation point that is 9.0 inches for softwoods (SPCD<300) and 11.0 inches for hardwoods (SPCD≥300)
Equation · Methods, Model development, 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
Directly predict total foliage dry weight as a function of D and H.
Output · Examples of tree-level calculations, step 15, p. 8
"Foliage","FOL_DW","202","240","MARINE_DIVISION",85,11.5070588235294,1.1,44.9
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
85
DBH range
22.86–114.05 cm
Method
NSVB segmented model (Eq. 2), coefficients for SPCD 202 in DIVISION 240 from table S9a (the total foliage 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
37.9
Foliage biomass (kg)
17.8
Carbon (kg), ×0.47
65.4
CO₂e (kg), ×44/12
Fitted DBH range02040608010020406080100DBH (cm)Foliage biomass (kg)Foliage biomass

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 = 33.537.937.9Value printed in the paper
Example 1 (p. 11) prints 83.634788855934 lb for D = 20 in, H = 110 ft; inputs and expected converted to cm, m, kg

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