Equations / Root biomass
Root system dry biomass from root collar diameter (Table 4, form 7)
As printed (Table 4, Root system rows, and Eq. (7; Ŷ = b0 × RCD^b1))
In this library's units, ready to compute (kg)
Root biomass = 0.023 * DRC^2.4519DRC- Root collar / stem base diameter, cm
For felled trees where only stump dimensions are available. RCD is the root collar diameter (mapped to DRC); the paper does not define its measurement height in the text read. Fit range quoted is the DBH range of the sample (RCD range not stated), so dbh_min/max are dropped for this equation. Weight function 1/(0.00007 × RCD^4.2484). Root system = taproot (including root collar) + lateral roots, excavated to full depth, fine roots included, dry mass at 105 C; stump above 20 cm is not part of it. Independent (not WNSUR additive) model, which the author recommends over the simultaneous ones. One of four independent root-system models in Table 4; all performed almost equally.
doi:10.1186/s13021-015-0027-4 · Open access · copy we read
93 trees (DBH range 5–32 cm; TH range 5.69–16 m)
Root system 4 99.79 28.8790
The dry weight of the root system was obtained by summing the dry weights of taproot and lateral roots (fine and coarse ones).
- Trees measured
- 93
- R²
- 0.9979
- Method
- Weighted nonlinear least squares (nls, Gauss-Newton); r2 is the adjusted R² in Table 5; CVr = 28.879%
- Where
- Mabote, Funhalouro, Panda, Mandlakaze and Chibuto districts, Inhambane and Gaza provinces
- Last checked
- 2026-11-02
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 = 10 | 6.51 | 6.51 | Computed from the printed form hand-computed from the Table 4 coefficients |
| DRC = 20 | 35.6 | 35.6 | Computed from the printed form hand-computed from the Table 4 coefficients |
| DRC = 30 | 96.3 | 96.3 | Computed from the printed form hand-computed from the Table 4 coefficients |
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- Root system dry biomass from DBH and height (Table 4, form 5) · Magalhães 2015 · DBH + Height
- Root system dry biomass from DBH (Table 4, form 4) · Magalhães 2015 · DBH
- Root system dry biomass from DBH²·H (Table 4, form 6) · same paper · Root biomass
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