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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Productivity and rainfall drive bacterial metabolism in tropical cascading reservoirs

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Freitas, Roberta [1] ; Vieira, Helena Henriques [2] ; de Moraes, Guilherme Pavan [2] ; de Melo, Michaela Ladeira [1] ; Henriques Vieira, Armando Augusto [2] ; Sarmento, Hugo [1]
Total Authors: 6
[1] Univ Fed Sao Carlos UFSCar, Lab Microbial Proc & Biodivers, Dept Hydrobiol DHb, Sao Carlos, SP - Brazil
[2] Univ Fed Sao Carlos UFSCar, Lab Phycol, DB, Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Hydrobiologia; v. 809, n. 1, p. 233-246, MAR 2018.
Web of Science Citations: 2

Tropical reservoirs are main carbon sources to the atmosphere, and bacterial metabolism is a key process in these emissions. Here, we explored the drivers of bacterial metabolism in four tropical cascading reservoirs forming a trophic state gradient, and compared them with those found in the literature (mainly from temperate regions). Bacterial production (BP) and growth efficiency (BGE) responded to trophic state-related variables, while bacterial respiration (BR) was weakly and negatively correlated to dissolved organic carbon (DOC). BP and BGE were higher in reservoirs with higher primary production, while BR (high throughout the whole study period) was greater in less productive reservoirs, where planktonic communities were often limited by phosphorus. The high BR and low BGE observed in less productive downstream reservoirs (i.e., less nutrients and organic matter availability) may be explained by increasing nutrient limitation and proportion of recalcitrant DOC along the cascade. Despite the lower productivity, oligotrophic reservoirs may be more important in terms of carbon biogeochemistry, considering that microbes in those systems mineralize more carbon than upstream productive reservoirs. Moreover, the drivers of bacterial metabolism may act differently according to latitude, as seasonality in the tropics is determined mainly by rainfall rather than temperature. (AU)

FAPESP's process: 11/50054-4 - Biodiversity of freshwater microalgae: germplasm bank and obtaining of molecular markers of cryopreserved species
Grantee:Armando Augusto Henriques Vieira
Support type: BIOTA-FAPESP Program - Thematic Grants
FAPESP's process: 14/14139-3 - Microbial processes and biodiversity in aquatic ecosystems
Grantee:Hugo Miguel Preto de Morais Sarmento
Support type: Research Grants - Young Investigators Grants