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Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The aquatic ecosystems can play a role as carbon-dioxide-source or carbon-dioxide-sink systems due to the high predominance of heterotrophic or autotrophic metabolism. The primary production can strongly affect the carbon balance (CO2) through the consumption of carbon dioxide in the photosynthesis, especially in eutrophic environment, acting as a carbon sink. The present study tested the hypothesis that the eutrophic reservoirs in tropical semi-arid region are carbon dioxide-sink systems due to the high primary productivity presented in these systems. Five Brazilian reservoirs from the semi-arid in the northeast region were monitored monthly during four years (2010 to 2013) with a prolonged drought event identified during the study. The results showed an increasing level of eutrophication over the period of prolonged drought, with the predominance of autotrophy. Significant negative correlations were observed between the partial pressure of CO2 (pCO2) (p<0,001) and chlorophyll-a in the Boqueir?o, Passagem das Tra?ras, Dourado and Gargalheiras reservoirs, showing a pattern of the carbon dioxide-sink systems. However, this pattern was not found in Cruzeta reservoir. In summary, in the tropical semi-arid region, hydrological and morphometric variables can lead to different behaviors of the water-supply reservoirs on the carbon metabolism. The eutrophic reservoirs evaluated showed a negative relationship between pCO2 and Chl-a, which suggests that these water bodies show an autotrophic metabolism and behave as carbon dioxide- sink systems / Os ecossistemas aqu?ticos podem atuar como emissores ou sequestradores de carbono em fun??o da predomin?ncia do metabolismo heterotr?fico ou autotr?fico. A produ??o prim?ria pode afetar fortemente o balan?o de carbono (CO2) atrav?s do consumo de di?xido de carbono na fotoss?ntese, especialmente em ambiente eutr?ficos, atuando como sumidouros. O presente estudo testou a hip?tese de que reservat?rios eutrofizados da regi?o tropical semi?rida s?o sequestradores de CO2 em fun??o da alta produtividade evidenciada nesses sistemas. Cinco reservat?rios da regi?o semi?rida do nordeste do Brasil foram monitorados mensalmente durante o per?odo de 2010 ? 2013, com um evento de seca prolongada identificado durante o estudo. Os resultados mostraram um crescente n?vel de eutrofiza??o ao longo do per?odo de seca prolongada com predomin?ncia de autotrofia. Foram observadas correla??es negativas significativas entre a press?o parcial de CO2 (pCO2) (p<0,001) e clorofila-a nos reservat?rios Boqueir?o, Passagem das Tra?ras, Dourado e Gargalheiras, evidenciando um padr?o de sequestro de CO2 desses sistemas. Por?m, este padr?o n?o foi encontrado no reservat?rio Cruzeta. Em s?ntese, na regi?o semi?rida tropical, as vari?veis hidrol?gicas e morfom?tricas podem direcionar diferentes comportamentos dos reservat?rios de abastecimento no metabolismo do carbono. Os reservat?rios eutrofizados avaliados apresentaram uma rela??o negativa entre pCO2 e Chl-a o que sugere que estes corpos h?dricos evidenciam um metabolismo autotr?fico e se comportam como sequestradores de CO2
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/16015 |
| Date | 31 March 2014 |
| Creators | Mendon?a J?nior, Jurandir Rodrigues de |
| Contributors | CPF:71502076004, http://lattes.cnpq.br/2999389235108507, Sarmento, Hugo Miguel Preto de Morais, CPF:01198282940, http://lattes.cnpq.br/4515469289999439, Vidal, Luciana de Oliveira, CPF:03885671638, http://lattes.cnpq.br/0455210600201967, Angelini, Ronaldo, CPF:13958013805, http://lattes.cnpq.br/6739463859587165, Becker, Vanessa |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-gradua??o em Engenharia Sanit?ria, UFRN, BR, Saneamento Ambiental; Meio Ambiente; Recursos H?dricos e Hidr?ulica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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