Equations / Aboveground biomass

North American taxa group: woodland juniper refit (Table 5 footnote 2)

Aboveground biomassWoodland Cupressaceae, mostly juniper (Cupressus spp., Juniperus monosperma, J. occidentalis, J. osteosperma) · CupressaceaeUnited StatesmixedRead from the original paper

Fitted on these 3 species and others the paper does not name here: Juniperus monosperma, Juniperus occidentalis, Juniperus osteosperma

Photo: (c) Paul Asman and Jill Lenoble, some rights reserved (CC BY) — 3 of the 3 species it was fitted on · iNaturalist photos, hover for credit

Photo: (c) Dominic Gentilcore, some rights reserved (CC BY), uploaded by Dominic Gentilcore — 3 of the 3 species it was fitted on · iNaturalist photos, hover for credit

Equation

As printed (Table 5 caption, p. 140)

ln(biomass) = β0 + β1 ln(diameter)

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

Aboveground biomass = exp(-2.719 + 2.2598 * ln(DRC))

DRC: Root collar / stem base diameter, cm

The authors' alternative to the woodland Cupressaceae equation, which they say 'seemed to predict low, possibly due to influence from early juniper diameter measurements'. It predicts 10–36% more, depending on diameter. The paper gives no n, range or R² for it. By root-collar diameter.

Source

Chojnacky, D.C., Heath, L.S., Jenkins, J.C. (2014). Updated generalized biomass equations for North American tree species. Forestry, 87(1), 129–151.

doi:10.1093/forestry/cpt053 · Open access · copy we read

[ln(biomass) = −2.7190 + 2.2598 ln(drc)]

Equation · Table 5 footnote 2, p. 140

predicted 10–36% higher, depending on diameter

Note · Table 5 footnote 2, p. 140

Cupressaceae J. osteosperma Juniper, Utah 65 0.54 3

Taxon · Table 4, p. 138

we did not include a correction (Baskerville, 1972) for underestimation

Correction factor · Methods, p. 139

Method: Refit of the woodland Cupressaceae taxon after adding pseudodata from unpublished studies where drc was measured by the current FIA definition; no back-transform correction
Where: United States (equations compiled from US and Canadian studies)
Last checked: 2026-11-03

Calculate

Root collar diameter (cm)

144

Aboveground biomass (kg)

67.5

Carbon (kg), ×0.47

247

CO₂e (kg), ×44/12

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%.

Inputs	Expected	We get	From
DRC = 30	144	144	Computed from the printed form computed from the published form at drc = 30 cm

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North American taxa group: woodland juniper refit (Table 5 footnote 2)

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