Título:	Vertical dynamics and carbon and nitrogen stocks in hydromorphic soils under different land uses on Marajó Island, Amazon.
Autoria:	CARVALHO, E. J. M. OLIVEIRA JUNIOR, R. C. de VELOSO, C. A. C. SANTOS, D. B. dos SILVA, A. R. MELEM JUNIOR, N. J. SILVEIRA FILHO, A. VALENTE, M. A.
Afiliação:	EDUARDO JORGE MAKLOUF CARVALHO, CPATU; RAIMUNDO COSME DE OLIVEIRA JUNIOR, CPATU; CARLOS ALBERTO COSTA VELOSO, CPATU; DARLISSON BENTES DOS SANTOS; ARYSTIDES RESENDE SILVA, CNPMS; NAGIB JORGE MELEM JUNIOR, CPAF-AP; AUSTRELINO SILVEIRA FILHO, CPATU; MOACIR AZEVEDO VALENTE.
Ano de publicação:	2026
Referência:	Revista de Geopolítica, v. 17, n. 3, e1814, 2026.
Conteúdo:	Tropical soils play a strategic role in global carbon (C) and nitrogen (N) cycles, acting simultaneously as important reservoirs of these elements and as systems highly sensitive to land-use changes. In hydromorphic and fluvio-marine Amazonian environments, such as those found on Marajó Island (PA), the vertical distribution and stability of these stocks remain poorly understood, particularly in subsurface layers. This study aimed to quantify and compare organic carbon and total nitrogen stocks along the soil profile, down to 100 cm depth, under three land-use systems: native forest, managed pasture, and silvopastoral system. Three representative soil profiles were described and sampled, with C and N contents determined by dry combustion using a CHN elemental analyzer, and stock calculations corrected based on soil bulk density. Integrated carbon stocks ranged from 42.80 to 126.81 Mg ha⁻¹, while nitrogen stocks varied between 3.05 and 6.67 Mg ha⁻¹. In all profiles, higher concentrations of C and N were observed in the surface layers; however, a significant fraction of the total stocks was identified below 40 cm, especially in the profile under stronger hydromorphic influence. The integrated C:N ratio up to 100 cm ranged from 13.9 to 19.0, indicating different degrees of stabilization and organic matter quality among the profiles. The results demonstrate that assessments restricted to surface layers significantly underestimate the actual C and N stocks in these environments, reinforcing the importance of considering the soil profile as a functional unit in carbon inventories and in climate change mitigation strategies in Amazonian fluvio-marine landscapes.
Thesagro:	Carbono Nitrogênio Solo Hidromórfico
Palavras-chave:	Carbono Orgânico do Solo Ambientes Flúvio-Marinhos
ISSN:	2177-3246.
Digital Object Identifier:	https://doi.org/10.56238/revgeov17n3-072
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CPATU)