{"id":"marroquin-2018-cembroides-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 cembroides stem biomass from DBH (cubic in ln D)","output":{"quantity":"stem_biomass"},"expression":"exp(-95.506 + 133.347*ln(D) - 61.223*(ln(D))^2 + 9.459*(ln(D))^3)","published":{"expression":"exp(-95.506 + 133.347*ln(Dn) - 61.223*(ln(Dn))^2 + 9.459*(ln(Dn))^3)","units":{"Dn":"cm"},"variables":{"Dn":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Pinus cembroides Zucc.","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":6.1,"dbh_max_cm":11,"h_min_m":2.9,"h_max_m":4.4,"r2":0.75,"method":"ln-ln least squares in R; no correction factor stated"},"evidence":[{"field":"expression","quote":"Bf  4  -95.506  42.35  133.347  60.68  -61.223  28.89  9.459  4.57","locator":"Cuadro 3 (Bf, modelo 4); R2 ajustada 0.75 in Cuadro 5"},{"field":"model form","quote":"ln B = β0 + β1 ln(Dn) + β2 ln(Dn)2 + β3 ln(Dn)3 + ε","locator":"Cuadro 1, modelo 4 (Polinomial de grado 3)"},{"field":"fit.n_trees","quote":"con una muestra de 50 árboles por especie","locator":"Resumen"}],"check":[{"inputs":{"D":7},"expected":6.3424,"origin":"computed","note":"computed from the published form (coefficients as printed, no correction factor)"},{"inputs":{"D":9},"expected":9.5247,"origin":"computed","note":"computed from the published form (coefficients as printed, no correction factor)"},{"inputs":{"D":11},"expected":13.977,"origin":"computed","note":"computed from the published form (coefficients as printed, no correction factor)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Bf = stem biomass, selected as best model for stem in P. cembroides (Resultados). The cubic term in ln D has a very large cancelling coefficient set; the fit is only meaningful inside the sampled DBH range. 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)."}