Seasonal variation in dissolved carbon concentrations and fluxes in the upper Purus River, southwestern Amazon

Autor(es)

Salimon, Cleber ^[1] ; Sousa, Eliete dos Santos ^{[1, 2]} ; Alin, Simone R. ^[3] ; Krusche, Alex Vladimir ^[2] ; Ballester, Maria Victoria ^[2]

Afiliação do(s) autor(es)

^[1] State Univ Paraiba, Fed Univ Acre, BR-69915900 Rio Branco, AC - Brazil

^[2] Ctr Energia Nucl Agr USP, BR-13400970 Piracicaba, SP - Brazil

^[3] NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 - USA

• Tipo de documento: Artigo Científico
• Fonte: BIOGEOCHEMISTRY; v. 114, n. 1-3, p. 245-254, JUL 2013.
• Citações Web of Science: 11

Resumo

One of the less studied components of carbon cycling that could improve our understanding of how and how strongly Amazonian ecosystems act as sinks or sources of carbon is the amount that is carried downstream by rivers. In this paper, we show that a headwater river can carry from 25 to 130 % of the reported sink for Amazonian forests, therefore not being negligible for ecosystem-level carbon budgets. Based on monthly measurements from May 2004 to April 2005 of the upper Purus River, southwestern Amazonia, we found that: water pH, dissolved oxygen, specific electrical conductivity, and dissolved inorganic carbon (DIC) were inversely related to water discharge and precipitation; pCO(2) was directly and strongly related to discharge and precipitation, and to a lesser extent to pH and dissolved oxygen; and dissolved organic carbon (DOC) was not related to any measured variable. Annual flux of dissolved carbon (DIC + DOC) at the sampling site was estimated as 604 +/- A 55 Gg C a(-1). More than 75 % was in the form of bicarbonate, with the remainder as CO2 and DOC. This amount is equivalent to 0.15 +/- A 0.01 Mg C ha(-1) a(-1) in the upstream drainage basin, which is on the same order of magnitude as terrestrial carbon fixation. (AU)

• Processo FAPESP: 03/07778-5 - Fluxos de carbono em ambientes fluviais e suas origens na Amazônia Ocidental
• Beneficiário: Cleber Ibraim Salimon
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado