info:eu-repo/semantics/article
High nutrient retention in chronically nutrient-rich lowland streams
Fecha
2016-12Registro en:
García, Victoria Julieta; Gantes, Hilda Patricia; Giménez, Loreta; Hegoburu, Cecilia; Ferreiro, Nicolas Andres; et al.; High nutrient retention in chronically nutrient-rich lowland streams; University of Chicago Press; Freshwater Science; 36; 1; 12-2016; 26-40
2161-9549
2161-9565
CONICET Digital
CONICET
Autor
García, Victoria Julieta
Gantes, Hilda Patricia
Giménez, Loreta
Hegoburu, Cecilia
Ferreiro, Nicolas Andres
Sabater, Francesc
Feijoó, Claudia Silvina
Resumen
Nutrient retention has been studied intensively in streams, but some mechanisms and processes are not yet entirely understood, especially in open-canopy streams. We evaluated PO43−, as soluble reactive P (SRP), and NH4+ uptake in 2 chronically enriched Pampean streams with different macrophytic abundance. We performed short-term nutrient additions to quantify SRP and NH4+ uptake metrics throughout the year, and we investigated which hydrological and biological factors influenced nutrient uptake. The results showed that SRP and NH4+ uptakes were high in relation to pristine and impaired streams elsewhere, and they did not saturate despite elevated background nutrient levels. NH4+ areal uptake rate fit in a 1st-order uptake model, but an exponential model described the relationship between SRP areal uptake rate and SRP concentration. Consistent with this finding, SRP uptake velocity tended to increase linearly, and SRP uptake length decreased linearly with SRP concentration. The analysis of factors influencing uptake metrics suggested that SRP uptake mainly depended on heterotrophic demand, whereas NH4+ uptake was enhanced under more autotrophic conditions. Our results showed that nutrient uptake metrics of enriched Pampean streams were similar to those observed in streams with low nutrient levels.