{"id":"repola-2008-betula-total","source":{"id":"repola-2008","citation":"Repola, J. (2008). Biomass equations for birch in Finland. Silva Fennica, 42(4), 605–624.","title":"Biomass equations for birch in Finland","authors":["Repola, J."],"year":2008,"venue":"Silva Fennica","doi":"10.14214/sf.236","url":"https://doi.org/10.14214/sf.236","read_url":"https://silvafennica.fi/pdf/236","access":"open","license":"CC BY-SA 4.0","checked_at":"2026-11-01","status":"current"},"name":"Birch total above-ground biomass excluding foliage, Model 1a (Eq. 11)","output":{"quantity":"agb","excludes":["foliage"]},"expression":"exp(-3.654 + 10.582 * (2 + 1.25*D)/((2 + 1.25*D) + 12) + 3.018 * H/(H + 22) + (0.00068 + 0.00727)/2)","published":{"expression":"exp(-3.654 + 10.582 * (2 + 1.25*d)/((2 + 1.25*d) + 12) + 3.018 * h/(h + 22) + (0.00068 + 0.00727)/2)","units":{"d":"cm","h":"m"},"variables":{"d":"D","h":"H"},"output_unit":"kg"},"taxon":{"level":"genus","name":"Betula","family":"Betulaceae","group":"broadleaf"},"region":{"scope":"national","countries":["FI"],"place":"Finland, mineral-soil stands (mostly southern and central Finland)","biomes":["boreal","temperate"]},"stand":"mixed","fit":{"n_trees":127,"dbh_min_cm":2.5,"dbh_max_cm":38,"cf":1.00398,"method":"Multivariate linear mixed model on ln(biomass) with stand random effects (fitted jointly with component equations); fixed part shown, with variance correction (var(u)+var(e))/2 added to the intercept"},"evidence":[{"field":"expression","quote":"ln(yki) = b0 + b1 dSki/(dSki + 12) + b2 hki/(hki + 22) + u5k + e5ki","locator":"Eq. 11, p. 612"},{"field":"expression","quote":"Total above-ground Eq. (11) N = 127 b0 –3.654 b1 10.582 b2 3.018; u5k 0.00068; e5ki 0.00727","locator":"Table 4, p. 613"},{"field":"expression","quote":"dSki = 2 + 1.25 dki","locator":"variable definitions"},{"field":"fit.cf","quote":"a variance correction term, (σu² + σe²)/2 … should be added to the intercept","locator":"Section 2.4 (2009) / Section 3 (2008)"}],"check":[{"inputs":{"D":20,"H":18},"expected":153.5575,"origin":"computed","note":"computed from the published form (with variance correction) at d = 20 cm, h = 18 m"}],"verification":"original_read","checked_at":"2026-11-01","notes":"B. pendula (66% of sample trees) and B. pubescens (34%) pooled. The paper states foliage biomass was not included in the total above-ground biomass, so this is AGB of stem, bark and living + dead branches without leaves. Variance correction (0.00068+0.00727)/2 added to the intercept in both forms. Sanity check: the uncorrected fixed part averaged over the four plot 4_11 trees of Table 7 gives 94.5 kg, matching Predfixed in Table 8."}