{"id":"dong-2020-ams2-stem-d-h","source":{"id":"dong-2020","citation":"Dong, L., Zhang, Y., Zhang, Z., Xie, L., & Li, F. (2020). Comparison of Tree Biomass Modeling Approaches for Larch (Larix olgensis Henry) Trees in Northeast China. Forests, 11(2), 202.","title":"Comparison of Tree Biomass Modeling Approaches for Larch (Larix olgensis Henry) Trees in Northeast China","authors":["Dong, L.","Zhang, Y.","Zhang, Z."],"year":2020,"venue":"Forests","doi":"10.3390/f11020202","url":"https://doi.org/10.3390/f11020202","read_url":"https://www.mdpi.com/1999-4907/11/2/202/pdf?version=1582977507","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current"},"name":"Larch stem biomass from DBH and height, AMS2","output":{"quantity":"stem_biomass"},"expression":"exp(-4.4649) * D^1.698 * H^1.4611","published":{"expression":"exp(-4.4649) * DBH^1.698 * H^1.4611","units":{"DBH":"cm","H":"m"},"variables":{"DBH":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Larix olgensis","family":"Pinaceae","group":"conifer"},"region":{"scope":"regional","countries":["CN"],"place":"Heilongjiang Province, Northeast China (40 plots, 10 sites)","biomes":["temperate"]},"stand":"plantation","fit":{"n_trees":229,"dbh_min_cm":2,"dbh_max_cm":35.7,"h_min_m":3.8,"h_max_m":27,"r2":0.9738,"method":"weighted NSUR (AMS2)"},"evidence":[{"field":"fit.n_trees","quote":"the dataset consisted of measurements on 229 larch trees using destructive biomass sampling","locator":"Section 2.1"},{"field":"fit.dbh_min_cm","quote":"DBH (cm) 229 2.0 35.7 17.9 6.9","locator":"Table 1"},{"field":"fit.h_min_m","quote":"H (m) 229 3.8 27.0 16.8 5.4","locator":"Table 1"},{"field":"expression","quote":"Stem −4.4649 0.0628 1.6980 0.0461 1.4611 0.0579","locator":"Table 3, AMS2, DBH and H"},{"field":"fit.r2","quote":"R2 0.9738 (AMS2, DBH and H, stem column)","locator":"Table 5, AMS2"}],"check":[{"inputs":{"D":10,"H":9},"expected":14.229,"origin":"computed","note":"hand-computed from the published form"},{"inputs":{"D":25,"H":20},"expected":216.55,"origin":"computed","note":"hand-computed from the published form"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Component equation of the AMS2 system. Additive AMS2 system (aggregated, no constraint) fitted by weighted nonlinear seemingly unrelated regression, the system the authors recommend over the base model when no subsample is available for random effects. Biomass models are exp(b0) * DBH^b1 [* H^b2] with no back-transform factor (nonlinear fit). The paper also gives base model, mixed-effects, AMS1, DMS1 and DMS2 parameters (Tables 2-4), not added here."}