{"id":"lambert-2005-eastern-redcedar-dbh-h-stem","source":{"id":"lambert-2005","citation":"Lambert, M.-C., Ung, C.-H., Raulier, F. (2005). Canadian national tree aboveground biomass equations. Canadian Journal of Forest Research, 35(8), 1996–2018.","title":"Canadian national tree aboveground biomass equations","authors":["Lambert, M.-C.","Ung, C.-H.","Raulier, F."],"year":2005,"venue":"Canadian Journal of Forest Research","doi":"10.1139/x05-112","url":"https://doi.org/10.1139/x05-112","read_url":"https://www.esf.edu/quest/documents/Lambertetal.2005.Canadatreebiomass.pdf","access":"paywalled","checked_at":"2026-11-03","status":"current","notes":"All 33 species are entered, each with total aboveground, stem (wood + bark), branch and foliage equations, for both the dbh-only set (Table 3) and the dbh + height set (Table 4). The paper's hardwood, softwood and all-species equations are not entered: they are meant for species outside the 33, and this library shows pooled fits only on the pages of species they name. Ung, Bernier & Guo (2008, CJFR 38:1123–1132, doi:10.1139/X07-224) re-estimated parameters for six species after adding British Columbia data and added eight BC species; no legal open copy of that paper was found (NRCan's repository lists it without a file), so Lambert 2005 parameters are used here."},"name":"Canadian national equation, eastern redcedar, dbh and height (stem wood plus stem bark; Table 4)","output":{"quantity":"stem_biomass"},"expression":"0.052 * D^1.7731 * H^0.7054 + 0.0283 * D^1.7079","published":{"expression":"0.052 * dbh^1.7731 * H^0.7054 + 0.0283 * dbh^1.7079","units":{"dbh":"cm","H":"m"},"variables":{"dbh":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Juniperus virginiana","family":"Cupressaceae","group":"conifer"},"region":{"scope":"regional","countries":["CA"],"place":"Ontario, Canada (ENFOR archival data, early 1980s)","biomes":["temperate"]},"fit":{"n_trees":33,"dbh_min_cm":2,"dbh_max_cm":38.2,"h_min_m":2.7,"h_max_m":12.8,"r2":0.98,"method":"Nonlinear seemingly unrelated regression with weight functions; additivity constrained so compartments sum to total"},"evidence":[{"field":"expression","quote":"y wood = β wood1D βwood2Hβwood3 + ewood","locator":"Eq. 3"},{"field":"expression","quote":"y bark = β bark1D βbark2Hβbark3 + e bark","locator":"Eq. 3"},{"field":"expression","quote":"Eastern redcedar bwood1 0.0520","locator":"Table 4, Eastern redcedar"},{"field":"expression","quote":"bwood2 1.7731","locator":"Table 4, Eastern redcedar"},{"field":"expression","quote":"bwood3 0.7054","locator":"Table 4, Eastern redcedar"},{"field":"expression","quote":"bbark1 0.0283","locator":"Table 4, Eastern redcedar"},{"field":"expression","quote":"bbark2 1.7079","locator":"Table 4, Eastern redcedar"},{"field":"expression","quote":"bbark3 —","locator":"Table 4, Eastern redcedar"},{"field":"fit.n_trees","quote":"Eastern redcedar        33     12.3±1.4     7.2±0.4       52.7±12.3","locator":"Table 2 (No. of trees)"},{"field":"fit.dbh_min_cm","quote":"(2.0;38.2)   (2.7;12.8)    (1.4;316.4)","locator":"Table 2, Eastern redcedar (ranges of dbh, height, total biomass)"},{"field":"fit.r2","quote":"Stem 0.4967 0.96 7.4 1.76 0.1072 0.98 5.3 2.15","locator":"Table 5, Eastern redcedar (AdjRSq in the dbh- and height-based set, second block)"}],"check":[{"inputs":{"D":20,"H":15},"expected":75.9177,"origin":"computed","note":"computed from the published form at dbh = 20 cm, H = 15 m"}],"verification":"original_read","checked_at":"2026-11-03","notes":"Stem from ground level to tree top, stem wood plus stem bark; the stem is the sum of the two compartment equations. Height drops out of the bark term: the paper leaves its height exponent blank (—, not significantly different from zero). 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."}