{"id":"bartelink-1997-ii-stem","source":{"id":"bartelink-1997","citation":"Bartelink, H. H. (1997). Allometric relationships for biomass and leaf area of beech (Fagus sylvatica L). Annales des Sciences Forestières, 54(1), 39–50.","title":"Allometric relationships for biomass and leaf area of beech (Fagus sylvatica L)","authors":["Bartelink, H. H."],"year":1997,"type":"journal-article","venue":"Annales des Sciences Forestières","doi":"10.1051/forest:19970104","url":"https://doi.org/10.1051/forest:19970104","read_url":"https://hal.science/hal-00883130/document","access":"open","checked_at":"2026-11-05","status":"current","notes":"The candidate identifies a publisher-hosted open URL, but the publisher returned HTTP 403 during this check. The publisher's access status and Crossref's type could not be independently confirmed."},"name":"Stem biomass from diameter (Table II)","output":{"quantity":"stem_biomass"},"expression":"0.0762 * D^2.523","published":{"expression":"0.0762 * dbh^2.523","units":{"dbh":"cm"},"variables":{"dbh":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Fagus sylvatica","group":"broadleaf"},"region":{"scope":"site","countries":["NL"],"place":"Forest area in the centre of the Netherlands","biomes":[]},"fit":{"n_trees":38,"r2":0.979,"method":"nonlinear least squares"},"evidence":[{"field":"expression","quote":"Y = c₀ + c₁*dbh^c₂; c₀ = *, c₁ = 0.0762, c₂ = 2.523; *Intercept not significant.","locator":"Table II, model and asterisk explanation below table; Stem row, p. 43 (rendered page-06)."},{"field":"expression","quote":"Stem * 0.0762 0.0224 2.523 0.088 0.979","locator":"Table II, p. 43 (rendered page)"},{"field":"expression","quote":"*Intercept not significant.","locator":"Table II, p. 43 (rendered page)"},{"field":"expression","quote":"k₂ = 0.0762*k²·⁵²³","locator":"Below Eq. 10, p. 48 (rendered page)"},{"field":"output","quote":"wood basic density of 550 kg dry weight per m3","locator":"Data collection, p. 41"},{"field":"published.units","quote":"Nonlinear models between tree biomass amounts or leaf area (Y: in kg or m²) and dbh (in cm).","locator":"Table II, p. 43 (rendered page)"},{"field":"fit.n_trees","quote":"The number of observations is 38.","locator":"Table II, p. 43 (rendered page)"},{"field":"fit.r2","quote":"Stem * 0.0762 0.0224 2.523 0.088 0.979","locator":"Table II, p. 43 (rendered page)"},{"field":"fit.method","quote":"In the case of nonlinear regression analysis the model was fitted directly by nonlinear least squares.","locator":"Data analysis, p. 42"},{"field":"taxon","quote":"beech (Fagus sylvatica L)","locator":"Title, p. 39"},{"field":"region","quote":"centre of the Netherlands.","locator":"Data collection, p. 40"}],"check":[{"inputs":{"D":15},"expected":70.669695158,"origin":"computed","note":"Computed from Table II; diameter is within the plotted sample."}],"verification":"original_read","checked_at":"2026-11-05","notes":"DBH is measured at 1.30 m. The nonsignificant intercept is omitted, consistent with the stem function used below Eq. 10. Stem dry mass was estimated from stem volume using a basic density of 550 kg/m³. R² is adjusted for degrees of freedom."}