{"id":"chave-2005-moist-h","source":{"id":"chave-2005","citation":"Chave, J., Andalo, C., Brown, S., et al. (2005). Tree allometry and improved estimation of carbon stocks and balance in tropical forests. Oecologia, 145(1), 87–99.","title":"Tree allometry and improved estimation of carbon stocks and balance in tropical forests","authors":["Chave, J.","Andalo, C.","Brown, S."],"year":2005,"venue":"Oecologia","doi":"10.1007/s00442-005-0100-x","url":"https://doi.org/10.1007/s00442-005-0100-x","read_url":"https://web.archive.org/web/2024id_/https://pdf.usaid.gov/pdf_docs/PA00KWXN.pdf","access":"paywalled","checked_at":"2026-11-01","status":"current"},"name":"Moist forest AGB with height (Model I)","output":{"quantity":"agb"},"expression":"exp(-2.977 + ln(rho * D^2 * H))","published":{"expression":"exp(-2.977 + ln(rho * D^2 * H))","units":{"D":"cm","rho":"g/cm3","H":"m"},"output_unit":"kg"},"taxon":{"level":"mixed","name":"Tropical broadleaf trees","group":"broadleaf"},"region":{"scope":"pantropical","countries":[],"place":"27 harvest sites across the tropics (America, Asia, Oceania); moist forest stands","biomes":["tropical"]},"stand":"natural","fit":{"dbh_min_cm":5,"dbh_max_cm":156,"rse":0.316,"method":"log-log regression on ρD²H with slope fixed at 1 (model I.5)"},"evidence":[{"field":"expression","quote":"⟨AGB⟩est = exp(−2.977 + ln(ρD²H)) ≡ 0.0509 × ρD²H","locator":"Choice of the best predictive models, Moist forest stands, p. 92"},{"field":"fit.rse","quote":"Moist −3.027 – – – 1,349 0.316 0.989 972","locator":"Table 2, model I.5 row (RSE printed once for the joint fit), p. 91"},{"field":"notes","quote":"These equations already include the correction factor (Eq. 7).","locator":"Choice of the best predictive models, p. 93"},{"field":"fit.dbh_max_cm","quote":"The models proposed here are valid in the range 5–156 cm for D, and 50–1,000,000 for ρD²H.","locator":"Recommendations, p. 97"},{"field":"published.units","quote":"D should be measured in centimeter, H in meter, and ρ in grams per cubic meter. The resulting AGB estimated from the equation is then in kilograms.","locator":"Recommendations, p. 97"}],"check":[{"inputs":{"D":30,"H":25,"rho":0.6},"expected":687.76,"origin":"computed","note":"computed with python3 from the published form"}],"verification":"original_read","checked_at":"2026-11-01","notes":"Printed equation already includes the Baskerville correction factor CF = exp(RSE²/2) (paper's Eq. 7); the paper does not print the CF value, so it is not repeated in fit.cf. RSE is the log-scale RSE of the joint fit across forest types (one value per model in the table). The paper writes 'ρ in grams per cubic meter', a misprint for g/cm³ (it defines wood specific gravity in g/cm³ in Methods). Forest types: dry = evapotranspiration exceeds rainfall more than 5 months/yr (roughly <1,500 mm/yr in lowlands); moist = 1–4-month dry season (ca. 1,500–3,500 mm/yr); wet = less than one dry month (>3,500 mm/yr, or montane cloud forest). Minus signs reconstructed from the PDF text layer, where the minus glyph is lost; intercept signs confirmed against Tables 2/4 (a + RSE²/2). For moist forests the authors chose model I.5 because the fitted slope was very close to 1. The paper gives the same model for moist mangrove stands."}