Data/hora: 05/06/2024 12:05:25

Biblioteca(s): 	Embrapa Amazônia Oriental.	
Data corrente: 	02/03/2011	
Data da última atualização: 	11/11/2022	
Autoria: 	DAVIDSON, E. A.; FIGUEIREDO, R. O.; MARKEWITZ, D.; AUFDENKAMPE, A. K.	
Afiliação: 	ERIC A. DAVIDSON, WOODS HOLE RESEARCH CENTER; RICARDO DE OLIVEIRA FIGUEIREDO, CPATU; DANIEL MARKEWITZ, UNIVERSITY OF GEORGIA; ANTHONY K. AUFDENKAMPE, STROUD WATER RESEARCH CENTER.	
Título: 	Dissolved CO2 in small catchment streams of eastern Amazonia: A minor pathway of terrestrial carbon loss.	
Ano de publicação: 	2010	
Fonte/Imprenta: 	Journal of Geophysical Research, v. 115, G04005, 2010.	
DOI: 	10.1029/2009JG001202	
Idioma: 	Inglês	
Conteúdo: 	Production of carbon dioxide (CO2) in soils can lead to supersaturation of dissolved free CO2 (pCO2) in groundwater, which later evades to the atmosphere as groundwater enters streams and rivers. This process could be a significant pathway for return of terrestrially fixed C to the atmosphere. We measured pCO2 monthly over two years at multiple stations along three streams from their headwaters in remnant mature forests through multiple land covers in Pará, Brazil. The pCO2 averaged 19,000 &#956;atm in headwaters and decreased to about 4,500 &#956;atm downstream. Similar values were measured in headwaters of two small pristine mature forest catchments. Two approaches were used to estimate groundwater pCO2 evasion: assuming that headwater pCO2 measurements reflected incoming groundwater pCO2 or that all entering stream water was in equilibrium with previously measured deep soil CO2. With these assumptions, losses from the terrestrial environment through aquatic evasion of pCO2 would be 0.02-0.15 Mg C ha&#8209;1 of land area yr&#8209;1, which is about 2-3 orders of magnitude lower than annual estimates of soil respiration and net primary productivity. However, downstream pCO2 values that appear to be in quasi-steady state indicate contributions from other C sources, such as aquatic primary production, soil erosion, dissolved organic matter, or litter inputs from streamside vegetation. Hence, lateral pCO2 loss from groundwater to streams is minor for most of the terrestrial ecosystems of this region, although C loss to streams could be significant for net terrestrial budgets in riparian ecosystems or areas experiencing erosion.	
Palavras-Chave: 	Perda de carbono.	
Thesaurus Nal: 	Amazonia.	
Categoria do assunto: 	P Recursos Naturais, Ciências Ambientais e da Terra	
Registro original: 	Embrapa Amazônia Oriental (CPATU)	
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