{"id":"romero-2020-mv1-husch-log","source":{"id":"romero-2020","citation":"Romero, F. M. B., Jacovine, L. A. G., Ribeiro, S. C., Torres, C. M. M. E., Silva, L. F. da, Gaspar, R. de O., et al. (2020). Allometric Equations for Volume, Biomass, and Carbon in Commercial Stems Harvested in a Managed Forest in the Southwestern Amazon: A Case Study. Forests, 11(8), 874.","title":"Allometric Equations for Volume, Biomass, and Carbon in Commercial Stems Harvested in a Managed Forest in the Southwestern Amazon: A Case Study","authors":["Romero, F. M. B.","Jacovine, L. A. G.","Ribeiro, S. C."],"year":2020,"venue":"Forests","doi":"10.3390/f11080874","url":"https://doi.org/10.3390/f11080874","read_url":"https://www.mdpi.com/1999-4907/11/8/874/htm","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current","notes":"Equations are for the commercial stem (stump cut at 30 cm, buttresses removed, crown left in the forest), not the whole tree."},"name":"Commercial stem volume from DBH, Husch log model (MV1)","output":{"quantity":"stem_volume"},"expression":"exp(-6.5125) * D^1.88558 * 1.0527","published":{"expression":"exp(-6.5125) * d^1.88558 * 1.0527","units":{"d":"cm"},"variables":{"d":"D"},"output_unit":"m3"},"taxon":{"level":"mixed","name":"20 commercial tree species of a managed forest (DBH >= 50 cm)","group":"broadleaf"},"region":{"scope":"site","countries":["BR"],"place":"Fazenda Antimari I and II, Porto Acre, Acre","biomes":["tropical"]},"stand":"natural","fit":{"n_trees":223,"dbh_min_cm":50.4,"dbh_max_cm":149.9,"r2":0.67,"cf":1.0527,"method":"Linear regression on ln(V) vs ln(d), back-transformed with correction factor"},"evidence":[{"field":"expression","quote":"ln(V) = β0 + β1 ln(d) + ε","locator":"Table 1, MV1 (Husch 1963; logarithmic)"},{"field":"fit.r2","quote":"MV1 −6.51250 * 1.88558 * 2.318 0.67 1011.70 1.621 1.0527","locator":"Table 3 (β0, β1, RMSE, R2, AIC, MAD, CF)"},{"field":"fit.dbh_min_cm","quote":"Total 223 50.4–149.9 79.6 ± 19.8 0.27–0.89 0.56 ± 0.16","locator":"Table 2 (n, DBH range and mean, wood density range and mean)"}],"check":[{"inputs":{"D":60},"expected":3.5222,"origin":"computed","note":"computed from the published form"},{"inputs":{"D":100},"expected":9.2283,"origin":"computed","note":"computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Commercial stem volume over bark (Smalian) in m3. Coefficients and CF as printed; the CF multiplies the back-transformed estimate. R2 is on the log scale. Applies to commercial stems only (stump at 30 cm, buttresses removed, crown left in the forest) of trees with DBH >= 50 cm; do not use for whole-tree totals. The authors selected the equations with commercial stem length l as the best ones; these are the ones that use only canonical variables."}