Tsuga canadensis / Stem biomass
Canadian national equation, eastern hemlock, dbh only (stem wood plus stem bark; Table 3)
© Ian Manning · CC BY · iNaturalistAs printed (Eq. 2)
In this library's units, ready to compute (kg)
Stem biomass = 0.0619 * D^2.3821 + 0.0139 * D^2.3282D- Diameter at breast height (1.3 m), cm
Stem from ground level to tree top, stem wood plus stem bark; the stem is the sum of the two compartment equations. r2 is the adjusted R² (AdjRSq) of this compartment in Table 5. Fitted on the original scale (weighted nonlinear seemingly unrelated regression), so there is no back-transform correction. Dead branches, cones and fruits are not part of aboveground biomass in this work (Materials). Stand type was not always recorded. Ung, Bernier & Guo (2008) later revised parameters for some species with British Columbia data; not used here.
doi:10.1139/x05-112 · Paywalled · copy we read
y bark = β bark1D βbark2 + e bark
Eastern hemlock bwood1 0.0619
bwood2 2.3821
bbark1 0.0139
bbark2 2.3282
Eastern hemlock 235 24.1±0.9 14.4±0.4 286.9±20.5
(1.3;51.4) (2.3;26.5) (0.6;1406.6)
Stem 0.0013 0.94 59.5 4.31 0.0074 0.97 45.0 3.52
- Trees measured
- 235
- DBH range
- 1.3–51.4 cm
- R²
- 0.94
- Method
- Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total
- Where
- Ontario and Quebec, Canada (ENFOR archival data, early 1980s)
- Last checked
- 2026-11-03
Shaded: the DBH range the model was fitted on. Other inputs held at the values above.
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 |
|---|---|---|---|
| D = 20 | 92.6 | 92.6 | Computed from the printed form computed from the published form at dbh = 20 cm |
Related
- Canadian national equation, eastern hemlock, dbh and height (stem wood plus stem bark; Table 4) · Lambert et al. 2005 · DBH + Height
- Canadian national equation, alpine fir, dbh only (branches; Table 3) · same paper · Branch biomass
- Canadian national equation, alpine fir, dbh and height (branches; Table 4) · same paper · Branch biomass
- Canadian national equation, alpine fir, dbh and height (foliage; Table 4) · same paper · Foliage biomass
- Canadian national equation, alpine fir, dbh and height (stem wood plus stem bark; Table 4) · same paper · Stem biomass
- Canadian national equation, alpine fir, dbh and height (sum of wood, bark, branches, foliage; Table 4) · same paper · Aboveground biomass
- Canadian national equation, alpine fir, dbh only (foliage; Table 3) · same paper · Foliage biomass
- Canadian national equation, alpine fir, dbh only (stem wood plus stem bark; Table 3) · same paper · Stem biomass
- Canadian national equation, alpine fir, dbh only (sum of wood, bark, branches, foliage; Table 3) · same paper · Aboveground biomass