{"id":"rufini-2010-spurr-r1-tvol-nobark","source":{"id":"rufini-2010","citation":"Rufini, A.L., Scolforo, J.R.S., Oliveira, A.D. de, Mello, J.M. de (2010). Equações volumétricas para o cerrado sensu stricto, em Minas Gerais. CERNE, 16(1), 1-11.","title":"Equações volumétricas para o cerrado sensu stricto, em Minas Gerais","authors":["Rufini, A.L.","Scolforo, J.R.S.","Oliveira, A.D. de"],"year":2010,"venue":"CERNE","doi":"10.1590/s0104-77602010000100001","url":"https://doi.org/10.1590/s0104-77602010000100001","read_url":"https://www.scielo.br/j/cerne/a/n7hz4jCWRWRnMgBGSCpD8Vp/?lang=pt&format=pdf","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Cerrado s.s. MG, Total volume without bark, Spurr log, SF 1, 2, 3, 4 sub-basins (region 1)","output":{"quantity":"total_volume"},"expression":"exp(-10.5266416714 + 1.0776947252 * ln(D^2 * H))","published":{"expression":"exp(-10.5266416714 + 1.0776947252 * ln(Dap^2 * H))","units":{"Dap":"cm","H":"m"},"variables":{"Dap":"D"},"output_unit":"m3"},"taxon":{"level":"mixed","name":"Cerrado sensu stricto tree species (mixed)","group":"mixed"},"region":{"scope":"regional","countries":["BR"],"place":"Minas Gerais, Sao Francisco river basin, SF 1, 2, 3, 4 sub-basins (region 1)","biomes":["tropical","dryland"]},"stand":"natural","fit":{"n_trees":157,"r2":0.9823,"method":"log-transformed linear regression (Spurr log) on Huber rigorous cubing data"},"evidence":[{"field":"expression","quote":"Ln(VTsc) = -10,5266416714 + 1,0776947252 * Ln((Dap^2) * H)","locator":"Table 1 (selected equations by region)"},{"field":"fit.n_trees","quote":"157 árvores para a região 1","locator":"2.2 Base de dados, p. 2"}],"check":[{"inputs":{"D":5,"H":3},"expected":0.00281243,"origin":"computed","note":"hand-computed from the published form (coefficients as printed)"},{"inputs":{"D":10,"H":5},"expected":0.0217272,"origin":"computed","note":"hand-computed from the published form (coefficients as printed)"},{"inputs":{"D":20,"H":8},"expected":0.160627,"origin":"computed","note":"hand-computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Dap, H and volume units are not spelled out beside the model; read as Dap in cm (derived from girth in cm at 1.30 m), total height H in m, volume in m3 (Table headings give Syx in m3); magnitudes are consistent with these units. No back-transformation correction factor is stated, so none is applied. R2 printed as a percentage. Volume without bark ('sem casca'). Total volume includes stem and branches down to 3 cm diameter."}