Roik, Mailson creator Machado, Sebastião do Amaral creator Figueiredo Filho, Afonso creator Sanquetta, Carlos Roberto creator Ruiz, Emilio Carlos Zilli creator text periodical abstract or summary bl. continuing eng Abstract The aim of this study was to quantify the aboveground biomass and organic carbon of Araucaria angustifolia (Bertol.) Kuntze in a Mixed Ombrophilous Montane Forest in the state of Paraná. The aboveground biomass determination was carried out according to the direct method, using 29 trees with Diameter at Breast Height (DBH) ≥ 40 cm. The trees were felled, cubed and weighed by compartments, which were sampled for determining moisture and carbon content. The average aerial biomass and carbon were 2,126.5 kg ind-1 and 935.8 kg ind-1, respectively. The moisture content resulted in a mean individual accumulation of 2,376.6 liters ind-1 of water. Age did not necessarily result in higher volume production but resulted in higher stem biomass production. Organic carbon accumulation by native A. angustifolia trees should support carbon credits as an incentive for the conservation of araucaria and Mixed Ombrophilous Forest fragments. Keywords: carbon credit, carbon sequestration, Mixed Ombrophilous Forest. Publicação on-line; 45 ref.; 4 tables; 1 illus.; Summary (En) FLORESTA CARBONO BIOMASSA ARAUCÁRIA ANGUSTIFOLIA Rio de Janeiro-RJ Instituto de Florestas - UFRRJ 1994 2025-0457 1415-0980 / ISSN 2179-8087 0nline BR2026001336 v. 27(3) p. 1-9; (2020) https://www.scielo.br/j/floram/a/zBVVnqZVrwX48kQZyDFXhzc/?format=pdf&lang=en https://www.scielo.br/j/floram/a/zBVVnqZVrwX48kQZyDFXhzc/?format=pdf&lang=en BR-BrBNA 260529 20260529102509.0 eng