{"id":"poudel-2016-df-foliage","source":{"id":"poudel-2016","citation":"Poudel, K. P., & Temesgen, H. (2016). Methods for estimating aboveground biomass and its components for Douglas-fir and lodgepole pine trees. Canadian Journal of Forest Research, 46(1), 77-87.","title":"Methods for estimating aboveground biomass and its components for Douglas-fir and lodgepole pine trees","authors":["Poudel, K. P.","Temesgen, H."],"year":2016,"venue":"Canadian Journal of Forest Research","doi":"10.1139/cjfr-2015-0256","url":"https://doi.org/10.1139/cjfr-2015-0256","read_url":"https://utoronto.scholaris.ca/bitstreams/36d392bb-40cc-4598-b73c-6745768b0acf/download","access":"open","license":"Author accepted manuscript (open access copy read; license not stated)","checked_at":"2026-11-02","status":"current"},"name":"Douglas-fir foliage biomass, simple SUR (D only)","output":{"quantity":"foliage_biomass"},"expression":"exp(-3.242 + 1.758 * ln(D))","published":{"expression":"exp(-3.242 + 1.758 * ln(D))","units":{"D":"cm"},"output_unit":"kg"},"taxon":{"level":"species","name":"Pseudotsuga menziesii","family":"Pinaceae","group":"conifer"},"region":{"scope":"regional","countries":["US"],"place":"Oregon, USA (several forests)","biomes":["temperate"]},"stand":"mixed","fit":{"n_trees":22,"dbh_min_cm":19.3,"dbh_max_cm":114,"method":"seemingly unrelated regression (simple SUR), component equations constrained to sum to total, fitted in original scale"},"evidence":[{"field":"expression","quote":"Foliage = exp(a41 + a42*X1); a41 = -3.242, a42 = 1.758","locator":"Eqs. 2-5 (X1 = ln DBH) and Table 3, Simple SUR, Douglas-fir"},{"field":"fit.n_trees","quote":"22 Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) and 33 lodgepole pine (Pinus contorta) trees","locator":"Materials and Methods, Data and Study Area"}],"check":[{"inputs":{"D":20},"expected":7.5723,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":50},"expected":37.9146,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":100},"expected":128.2382,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Read from the author's accepted manuscript (draft, manuscript ID cjfr-2015-0256.R1), not the typeset article; values may differ from the final print. Fitted in original scale (nonlinear SUR), so no log back-transform correction. DBH in cm, biomass in kg (Eq. 2-5 text).  Extended SUR models using height and crown length are not included (crown length is not a canonical variable)."}