{"id":"repola-2014-stem-pine","source":{"id":"repola-2014","citation":"Repola, J., Ahnlund Ulvcrona, K. (2014). Modelling biomass of young and dense Scots pine (Pinus sylvestris L.) dominated mixed forests in northern Sweden. Silva Fennica, 48(5), 1190.","title":"Modelling biomass of young and dense Scots pine (Pinus sylvestris L.) dominated mixed forests in northern Sweden","authors":["Repola, J.","Ahnlund Ulvcrona, K."],"year":2014,"venue":"Silva Fennica","doi":"10.14214/sf.1190","url":"https://doi.org/10.14214/sf.1190","read_url":"https://silvafennica.fi/pdf/1190","access":"open","checked_at":"2026-11-02","status":"current"},"name":"Scots pine stem biomass, young dense stands, N Sweden (Table 5)","output":{"quantity":"stem_biomass"},"expression":"exp(-3.010 + (0.003 + 0.018) / 2 + 7.999 * D / (D + 8) + (2.959) * H / (H + 13))","published":{"expression":"exp(-3.010 + (0.003 + 0.018) / 2 + 7.999 * dbh / (dbh + 8) + (2.959) * h / (h + 13))","units":{"dbh":"cm","h":"m"},"variables":{"dbh":"D","h":"H"},"output_unit":"kg"},"taxon":{"level":"species","name":"Pinus sylvestris","family":"Pinaceae","group":"conifer"},"region":{"scope":"regional","countries":["SE"],"place":"Six young, dense, naturally regenerated stands in northern Sweden (63.26-65.69 N)","biomes":["boreal"]},"stand":"natural","fit":{"n_trees":126,"dbh_min_cm":1,"dbh_max_cm":22,"h_min_m":1.7,"h_max_m":11.7,"method":"linear mixed model of ln(biomass) with random stand effect; ln(y) = Intercept + b1 dbh/(dbh + n) + b2 h/(h + m)"},"evidence":[{"field":"expression","quote":"Stem, kg, Scots pine: Intercept −3.010; dbh/(dbh + n) 7.999; h/(h + m) 2.959; n 8; m 13; var(uk) 0.003; var(eki) 0.018","locator":"Table 5, p. 12"},{"field":"expression","quote":"a variance correction term, ((var(uk) + var(eki))/2) should be added to the intercept to correct for bias due to the logarithmic transformation","locator":"Section 2.6, p. 10"},{"field":"fit.n_trees","quote":"In total, 280 trees were included in this destructive aboveground biomass study, of which 126 were pine, 68 spruce and 86 birch.","locator":"Section 2.4, p. 6"},{"field":"fit.dbh_max_cm","quote":"The range of dbh was 1–22 cm, 1–21 cm and 1–11 cm for pine, spruce and birch, respectively","locator":"Section 2.4, p. 6"},{"field":"fit.h_max_m","quote":"The range of heights was 1.7–11.7 m, 1.6–13.3 m and 1.8–8.6 m for pine, spruce and birch, respectively","locator":"Section 2.4, p. 6"}],"check":[{"inputs":{"D":5,"H":5},"expected":2.4571,"origin":"computed","note":"hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction"},{"inputs":{"D":12,"H":9},"expected":20.2955,"origin":"computed","note":"hand-computed from the Table 5 coefficients with the (var(u) + var(e))/2 intercept correction"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Fitted on pine-dominated mixed stands; fit n, DBH and height ranges are the species sample ranges. Expression applies the paper's stated additive correction (var(uk) + var(eki))/2 to the intercept. Variance values are as printed in Table 5; no other correction factor is stated. "}