{"id":"song-2026-needles","source":{"id":"song-2026","citation":"Song, J., Jang, M., Lee, B., et al. (2026). Allometric Equations for Estimating Crown Fuel Biomass of Pinus densiflora in South Korea. Forests, 17(5), 549.","title":"Allometric Equations for Estimating Crown Fuel Biomass of Pinus densiflora in South Korea","authors":["Song, J.-h.","Jang, M.-n.","Lee, B.-d."],"year":2026,"venue":"Forests","doi":"10.3390/f17050549","url":"https://doi.org/10.3390/f17050549","read_url":"https://www.mdpi.com/1999-4907/17/5/549","access":"open","license":"CC BY 4.0","checked_at":"2026-11-02","status":"current"},"name":"Pinus densiflora needle (crown fuel) biomass from DBH (Table 3)","output":{"quantity":"foliage_biomass"},"expression":"exp(1.893 * ln(D) - 3.835) * 1.028","published":{"expression":"exp(1.893 * ln(DBH) - 3.835) * 1.028","units":{"DBH":"cm"},"variables":{"DBH":"D"},"output_unit":"kg"},"taxon":{"level":"species","name":"Pinus densiflora","family":"Pinaceae","group":"conifer"},"region":{"scope":"national","countries":["KR"],"place":"Seven sites across South Korea (Daegu, Yangyang, Yeongju, Bonghwa, Goryeong, Mungyeong, Seosan)","biomes":["temperate"]},"stand":"natural","fit":{"n_trees":67,"dbh_min_cm":5,"dbh_max_cm":35.1,"h_min_m":4.5,"h_max_m":19.6,"cf":1.028,"method":"OLS regression of ln(W) on ln(DBH), back-transformed with a correction factor"},"evidence":[{"field":"expression","quote":"ln(Wt) = a ln(DBH) + b","locator":"Eq. 1"},{"field":"expression","quote":"Wt = exp(a ln(DBH) + b) × CF","locator":"Eq. 4"},{"field":"expression","quote":"Needles 67 1.893 (0.070) −3.835 (0.200) 0.917 0.236 1.028","locator":"Table 3 (n, a, b, R2adj, s.e.e., correction factor)"},{"field":"fit.n_trees","quote":"A total of 67 sample trees were selected across the seven study areas","locator":"Section 2.2"},{"field":"fit.dbh_max_cm","quote":"The average DBH and tree height were 18.1 cm (range: 5.0–35.1 cm) and 11.1 m (range: 4.5–19.6 m)","locator":"Section 2.2"}],"check":[{"inputs":{"D":10},"expected":1.7357,"origin":"computed","note":"computed from the Table 3 coefficients and correction factor"},{"inputs":{"D":25},"expected":9.835,"origin":"computed","note":"computed from the Table 3 coefficients and correction factor"}],"verification":"original_read","checked_at":"2026-11-02","notes":"Needle dry mass (crown fuel), a foliage-only equation. Printed R2adj is 0.917. In Table 3 column 'a' is the ln(DBH) slope and 'b' the intercept, per Eq. 1. Correction factor 1.028 as printed (exp(s.e.e.^2/2)). Natural forests with a mix of managed and unmanaged stands. The paper also prints branch diameter-class equations (<0.5, 0.5-1, 1-2, 2-4, >4 cm) and a total crown fuel equation (needles + branches, no stem); those are not added because they are partial-branch or crown-only totals with no matching output quantity."}