{"id":"miyakuni-2004-root-b-all-ages","source":{"id":"miyakuni-2004","citation":"Miyakuni, K., Heriansyah, I., Heriyanto, N. M., & Kiyono, Y. (2004). Allometric Biomass Equations, Biomass Expansion Factors and Root-to-shoot Ratios of Planted Acacia mangium Willd. Forests in West Java, Indonesia. Journal of Forest Planning, 10(2), 69-76.","title":"Allometric Biomass Equations, Biomass Expansion Factors and Root-to-shoot Ratios of Planted Acacia mangium Willd. Forests in West Java, Indonesia","authors":["Miyakuni, K.","Heriansyah, I.","Heriyanto, N. M."],"year":2004,"venue":"Journal of Forest Planning","doi":"10.20659/jfp.10.2_69","url":"https://doi.org/10.20659/jfp.10.2_69","read_url":"https://www.jstage.jst.go.jp/article/jfp/10/2/10_KJ00007911299/_pdf","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Planted Acacia mangium, West Java, root biomass from D, all ages (model B)","output":{"quantity":"bgb"},"expression":"0.0058 * D^2.821","published":{"expression":"0.0058 * dbh^2.821","units":{"dbh":"cm"},"variables":{"dbh":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Acacia mangium","family":"Fabaceae","group":"broadleaf"},"region":{"scope":"regional","countries":["ID"],"place":"Maribaya and Tenjo ranger districts (Parungpanjang), Perhutani, West Java","biomes":["tropical"]},"stand":"plantation","fit":{"n_trees":59,"r2":0.9883,"method":"log-linear least squares of Y = a·dbh^b"},"evidence":[{"field":"expression","quote":"Y = a·dbh^b; a = 0.0058, b = 2.821, r2 = 0.9883","locator":"Table 6, model B, stand age 3-10"},{"field":"fit.n_trees","quote":"We selected 15 trees from the 3-year-old stand, 12 trees from the 5-year-old stand, 16 trees from the 8-year-old stand, and 16 trees from the 10-year-old stand","locator":"Destructive Sampling to Measure the Biomass of Individual Trees, p. 72"}],"check":[{"inputs":{"D":5},"expected":0.54353,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":10},"expected":3.8409,"origin":"computed","note":"computed from the published form (coefficients as printed)"},{"inputs":{"D":20},"expected":27.141,"origin":"computed","note":"computed from the published form (coefficients as printed)"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Model B (the authors' recommended general equation): all four stand ages combined (3-10 yr). Fitted in log space (log-linear) and printed as a power law; the paper states no back-transformation correction factor and none is applied. The paper does not print the sampled dbh range. Aboveground biomass is the sum of the above-ground organs as defined by the authors (Yag)."}