{"id":"vale-2002-agb-d30","source":{"id":"vale-2002","citation":"Vale, A.T., Fiedler, N.C., Silva, G.F. (2002). Avaliação energética da biomassa do cerrado em função do diâmetro das árvores. Ciência Florestal, 12(2), 115-126.","title":"Avaliação energética da biomassa do cerrado em função do diâmetro das árvores","authors":["Vale, A.T.","Fiedler, N.C.","Silva, G.F."],"year":2002,"venue":"Ciência Florestal","doi":"10.5902/198050981686","url":"https://doi.org/10.5902/198050981686","read_url":"https://periodicos.ufsm.br/cienciaflorestal/article/download/1686/962","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Cerrado sensu stricto wood + bark dry mass from D30 (quadratic, Fig. 5)","output":{"quantity":"agb"},"expression":"26.501 - 7.0631 * D30 + 0.5169 * D30^2","published":{"expression":"26.501 - 7.0631 * x + 0.5169 * x^2","units":{"x":"cm"},"variables":{"x":"D30"},"output_unit":"kg"},"taxon":{"level":"mixed","name":"Cerrado sensu stricto woody species (47 species)","group":"mixed"},"region":{"scope":"site","countries":["BR"],"place":"Fazenda Água Limpa, Universidade de Brasília, Distrito Federal","biomes":["tropical"]},"stand":"natural","fit":{"r2":0.92,"method":"Quadratic regression y = b0 + b1x + b2x2 (SAEG); best of 12 equations tested"},"evidence":[{"field":"expression","quote":"y = 26,501 - 7,0631*x + 0,5169*x2","locator":"Figura 5, p. 124"},{"field":"fit.r2","quote":"R2 = 0,92","locator":"Figura 5, p. 124"},{"field":"input","quote":"em função do diâmetro a 30 cm de altura do solo","locator":"Resumo"},{"field":"output","quote":"Massa seca total (kg/árv.)","locator":"Figura 5, p. 124"}],"check":[{"inputs":{"D30":10},"expected":7.56,"origin":"computed","note":"computed from the printed Figure 5 equation"},{"inputs":{"D30":20},"expected":91.999,"origin":"computed","note":"computed from the printed Figure 5 equation"}],"verification":"original_read","checked_at":"2026-11-02","notes":"x is the stem diameter at 30 cm above ground (D30), not DBH. Total = wood plus bark of trunk and branches; branches under 3 cm basal diameter were removed before weighing, and the paper does not say how foliage was treated, so no exclusion is declared. The paper states 3 trees per diameter class in seven classes but not a total n, so n_trees and the fitted diameter range are left out."}