{"id":"flade-2021-picea-branch-nls","source":{"id":"flade-2021","citation":"Flade, L., Hopkinson, C., & Chasmer, L. (2021). Aboveground Biomass Allocation of Boreal Shrubs and Short-Stature Trees in Northwestern Canada. Forests, 12(2), 234.","title":"Aboveground Biomass Allocation of Boreal Shrubs and Short-Stature Trees in Northwestern Canada","authors":["Flade, L.","Hopkinson, C.","Chasmer, L."],"year":2021,"venue":"Forests","doi":"10.3390/f12020234","url":"https://doi.org/10.3390/f12020234","read_url":"https://www.mdpi.com/1999-4907/12/2/234/htm","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current","notes":"Only the short-stature tree component models (Table 3, cross-sectional area at 0.3 m) are added. Shrub models (Table 2) use plant volume, which has no canonical variable."},"name":"Picea spp. branch biomass, cross-sectional area at 0.3 m (NLS)","output":{"quantity":"branch_biomass"},"expression":"19.1842 * (0.785398163397448 * D30^2)^1.2866 / 1000","published":{"expression":"19.1842 * (0.785398163397448 * D30^2)^1.2866","units":{"D30":"cm"},"output_unit":"g"},"taxon":{"level":"genus","name":"Picea spp.","family":"Pinaceae","group":"conifer"},"region":{"scope":"regional","countries":["CA"],"place":"Sporadic to discontinuous permafrost zone, Taiga Plains and Taiga Shield ecozones, northwestern Canada","biomes":["boreal"]},"stand":"natural","fit":{"r2":0.904,"method":"iterative nonlinear least squares power function, y = β x^α (unweighted), x = cross-sectional area"},"evidence":[{"field":"expression","quote":"Picea spp. Branches NLS 19.1842 1.2866 0.904 (columns: β, SE(β), α, SE(α), RMSE, R2); y = βx^α + ε (Eq. 2)","locator":"Table 3, Eqs. 2-5"}],"check":[{"inputs":{"D30":2},"expected":0.0837,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D30":5},"expected":0.8842,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D30":8},"expected":2.9634,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Paper's predictor is cross-sectional area (cm2) of the stem(s) at 0.3 m; converted here to D30 as pi/4 * D30^2 (pi written as 0.785398163397448 * ...), so for multi-stemmed trees D30 is the equivalent diameter of the summed cross-sectional area. Paper output is in g dry mass; canonical form divides by 1000.  Fit range of the predictor is not stated, so none is given."}