{"id":"marroquin-2018-halepensis-stem","source":{"id":"marroquin-2018","citation":"Marroquín Morales, P., Méndez González, J., Jiménez Pérez, J., Aguirre Calderón, O. A., & Yerena Yamallel, J. I. (2018). Estimación de biomasa aérea en Pinus cembroides Zucc. y Pinus halepensis Mill. en Saltillo, Coahuila. Revista Mexicana de Ciencias Forestales, 9(47).","title":"Estimación de biomasa aérea en Pinus cembroides Zucc. y Pinus halepensis Mill. en Saltillo, Coahuila","authors":["Marroquín Morales, P.","Méndez González, J.","Jiménez Pérez, J."],"year":2018,"venue":"Revista Mexicana de Ciencias Forestales","doi":"10.29298/rmcf.v9i47.172","url":"https://doi.org/10.29298/rmcf.v9i47.172","read_url":"https://www.redalyc.org/journal/634/63457163006/html/","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Pinus halepensis stem biomass from DBH and height (combined variable)","output":{"quantity":"stem_biomass"},"expression":"exp(-1.198 + 0.633*ln(D^2*H))","published":{"expression":"exp(-1.198 + 0.633*ln(Dn^2*H))","units":{"Dn":"cm","H":"m"},"variables":{"Dn":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Pinus halepensis Mill.","family":"Pinaceae","group":"conifer"},"region":{"scope":"site","countries":["MX"],"place":"Cuauhtémoc and El Recreo ejidos, Saltillo, Coahuila","biomes":["dryland","temperate"]},"stand":"plantation","fit":{"n_trees":50,"dbh_min_cm":6.9,"dbh_max_cm":22.8,"h_min_m":3.1,"h_max_m":6.7,"r2":0.85,"method":"ln-ln least squares in R; no correction factor stated"},"evidence":[{"field":"expression","quote":"Bf  2  -1.198  0.30  0.633  0.04","locator":"Cuadro 4 (Bf, modelo 2); R2 ajustada 0.85 in Cuadro 5"},{"field":"model form","quote":"ln B = β0 + β1 ln(Dn2 H) + ε","locator":"Cuadro 1, modelo 2 (Variable combinada)"},{"field":"fit.n_trees","quote":"con una muestra de 50 árboles por especie","locator":"Resumen"}],"check":[{"inputs":{"D":8,"H":4},"expected":10.096,"origin":"computed","note":"computed from the published form (coefficients as printed, no correction factor)"},{"inputs":{"D":14,"H":5},"expected":23.614,"origin":"computed","note":"computed from the published form (coefficients as printed, no correction factor)"},{"inputs":{"D":21,"H":6},"expected":44.281,"origin":"computed","note":"computed from the published form (coefficients as printed, no correction factor)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Bf model 2, selected for P. halepensis in Resultados (modelo 2 for Bhr, Bf and Bt). The Cuadro 4 row lists the intercept then the slope. Leaves-branches (Bhr) model 2 is not stored: it combines two components with no matching output quantity. Decimal point in the original. Plantation 22 years old. Biomass by the indirect Adelaide method (leaves-branches by reference branch, stem by Smalian volume times basic density), so the stem and total values are not weighed directly. Cuadro 5 R2 is the adjusted R2. The paper prints no correction factor for the ln back-transform, so none is applied. Ranges are from Cuadro 2 (n = 50)."}