Tree Allometrics

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Chinese fir total tree biomass (compatible total-biomass system)

Total biomassCunninghamia lanceolata · CupressaceaeChinamixedRead from the original paper
Photo of Cunninghamia lanceolata
© harum.koh · CC BY-SA · iNaturalist
Equation

As printed (Table 8, Eq. 29-31)

Btotal = 0.065662D 1.750420 H 0.780381 + 0.024760 (D 2 H) 0.774387 (29)

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

Total biomass = 0.065662 * D^1.750420 * H^0.780381 + 0.024760 * (D^2 * H)^0.774387
D
Diameter at breast height (1.3 m), cm
H
Total tree height, m

Final total-biomass model (aboveground + root). Compatible total-biomass system (aboveground fitted independently, total and root fitted jointly by simultaneous estimation; weighted nonlinear least squares). Total = aboveground + root. The paper lists the sample as stratified random felled trees across eight diameter classes (4-32 cm) from 2022-2023; the reported minimum and maximum DBH and height are for all sampled trees of the species (Table 1). Root biomass was measured on a subset only (whole-root excavation: root collar, coarse roots, fine roots), so root and total fit ranges are not given beyond the full sample. No back-transform factor (nonlinear fit). The paper also gives aboveground-component (stem, crown, wood, bark, branch, foliage) systems (Tables 17-39), not added here.

Source
The sample comprised 154 Chinese fir, 150 poplar, and 157 oak trees.
Trees measured · Section 2.2
DBH (cm) 2.2 35.3 19.88 7.77
Smallest DBH · Table 1, Chinese fir
Tree height (m) 2.5 25.6 14.25 5.38
h min m · Table 1, Chinese fir
(20) 0.065662 1.750420 0.780381 0.024760 0.774387 10.77 7.19 44.54 6.16
Equation · Table 8 (parameters)
R2 0.9208 (total biomass model, evaluation table)
R² · Table 11
Trees measured
154
DBH range
2.2–35.3 cm
Height range
2.5–25.6 m
R²
0.9208
Method
weighted nonlinear least squares
Where
Hunan Province (14 prefecture-level cities and autonomous prefectures)
Last checked
2026-11-02
Calculate
Height from
25.33
Total biomass (kg)
11.91
Carbon (kg), ×0.47
43.66
CO₂e (kg), ×44/12
Fitted DBH range050100150200250300510152025303540DBH (cm)Total biomass (kg)Total 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 = 10, H = 925.325.3Computed from the printed form
hand-computed from the published form
D = 30, H = 20310.8310.8Computed from the printed form
hand-computed from the published form

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