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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Agriculture influences ammonium and soluble reactive phosphorus retention in South American headwater streams

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Autor(es):
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Fernandes Cunha, Davi Gasparini [1] ; Finkler, Nicolas Reinaldo [1] ; Gomez, Nora [2] ; Cochero, Joaquin [2] ; Donadelli, Jorge Luis [2] ; Saltarelli, Wesley Aparecido [1] ; Calijuri, Maria do Carmo [1] ; Poli Miwa, Adriana Cristina [1] ; Tromboni, Flavia [3] ; Dodds, Walter K. [4] ; Boechat, Iola Goncalves [5] ; Gucker, Bjorn [5] ; Thomas, Steven A. [6]
Número total de Autores: 13
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Dept Hidraul & Saneamento, Escola Engn Sao Carlos, Sao Paulo, SP - Brazil
[2] Univ Nacl La Plata, Fac Ciencias Nat & Museo, Inst Limnol Dr Raul A Ringuelet, Consejo Nacl Invest Cient & Tecn, Buenos Aires, DF - Argentina
[3] Univ Nevada, Global Water Ctr, Reno, NV 89557 - USA
[4] Kansas State Univ, Div Biol, Ackert Hall, Manhattan, KS 66506 - USA
[5] Univ Fed Sao Joao del Rei, Dept Geociencias, Sao Joao Del Rei - Brazil
[6] Univ Nebraska Lincoln, Inst Agr & Nat Resources, Sch Nat Resources, Lincoln, NE - USA
Número total de Afiliações: 6
Tipo de documento: Artigo Científico
Fonte: ECOHYDROLOGY; v. 13, n. 2 DEC 2019.
Citações Web of Science: 0
Resumo

Agricultural activities can affect the delivery of nutrients to streams, riparian canopy cover, and the capacity of aquatic systems to process nutrients and sediments. There are few measures of nutrient uptake and metabolism from tropical or subtropical streams in general, and even fewer from tropical regions of South America. We examined ammonium (NH4+) and soluble reactive phosphorus (SRP) retention in streams in Brazil and Argentina. We selected 12 streams with relatively little or extensive agricultural activity and conducted whole-stream nutrient additions and measurements of gross primary production and ecosystem respiration. We used multiple linear regression to determine potential drivers of nutrient uptake metrics across the streams. Nutrient concentrations and retention differed significantly between land use categories. Both NH4+ and SRP concentrations were higher in the agricultural sites (means of 161 and 495 mu g l(-1), respectively), whereas metabolic rates were slower and transient storage was smaller. Our analysis indicated that agriculture increased ambient uptake lengths and decreased uptake velocities. The regression models revealed that ambient SRP had a positive effect on NH4+ uptake and vice versa, suggesting strong stoichiometric controls. Drivers for nutrient uptake in streams with low-intensity agriculture also included canopy cover, temperature, and ecosystem respiration rates. Nutrient assimilation in agricultural sites was influenced by a higher number of variables (gross primary production for SRP, discharge, and transient storage for both nutrients). Our results indicate agricultural activity changes both the magnitude of in-stream nutrient uptake and the mechanisms that control its variation, with important implications for South American streams under agricultural intensification. (AU)

Processo FAPESP: 16/14176-1 - Retenção de macronutrientes por riachos do Cerrado (SP) e sua relação com o metabolismo aquático em gradiente de condições ambientais: uma abordagem sobre os serviços ecossistêmicos
Beneficiário:Davi Gasparini Fernandes Cunha
Linha de fomento: Auxílio à Pesquisa - Regular
Processo FAPESP: 18/13171-1 - Efeitos de fontes pontuais de poluição sobre a retenção de nutrientes em riachos tropicais: manipulação experimental da razão estequiométrica de nitrogênio e fósforo
Beneficiário:Nícolas Reinaldo Finkler
Linha de fomento: Bolsas no Brasil - Doutorado
Processo FAPESP: 17/50397-5 - Understanding the influence of land use practices and canopy cover restoration on nutrient spiraling in tropical and temperate stream ecosystems
Beneficiário:Davi Gasparini Fernandes Cunha
Linha de fomento: Auxílio à Pesquisa - Regular
Processo FAPESP: 17/18519-3 - Medidas estruturais e não estruturais para recuperação de riachos tropicais: efeitos sobre o metabolismo aquático e a retenção de macronutrientes
Beneficiário:Wesley Aparecido Saltarelli
Linha de fomento: Bolsas no Brasil - Doutorado