To access the full text documents, please follow this link: http://hdl.handle.net/2445/101340

A round-trip ticket: the importance of release processes for in-stream nutrient spiraling
Schiller Calle, Daniel von; Bernal Berenguer, Susana; Sabater i Comas, Francesc; Martí, Eugènia
Universitat de Barcelona
Most nutrient-spiraling studies have focused on estimates of gross uptake (Ugross), which show that streams take up dissolved inorganic nutrients very efficiently. However, studies based on estimates of net uptake (Unet) emphasize that streams tend to be at biogeochemical steady state (i.e., Unet ≈ 0), at least on a time scale of hours. These findings suggest that streams can be highly reactive ecosystems but remain at short-term biogeochemical steady state if Ugross is counterbalanced by release (R), a process that remains widely unexplored. Here, we propose a novel approach to infer R by comparing Unet and Ugross estimated from ambient and plateau concentrations obtained from standard short-term nutrient additions along a reach. We used this approach to examine the temporal variation of R and its balance with Ugross in 2 streams with contrasting hydrological regime (i.e., perennial vs intermittent) during 2 years. We focused on the spiraling metrics of NH4+ and soluble reactive P (SRP), essential sources of N and P in stream ecosystems. R differed substantially between the 2 streams. The perennial stream had a higher proportion of dates with R > 0 and a 2× higher mean R than the intermittent stream for both nutrients. Despite these differences, the magnitude of R and Ugross tended to be similar for both nutrients within each stream, which lead to Unet ≈ 0 in most cases. A notable exception occurred for SRP in the intermittent stream, where R tended to be higher than Ugross during most of the winter period, probably because of desorption of P from stream sediments. Together, our findings shed light on the contribution of release processes to the dynamics of nutrient spiraling and support the idea that streams can be active ecosystems with high spiraling fluxes while simultaneously approaching short-term biogeochemical steady-state.
Nitrogen
Fòsfor
Nutrients (Medi ambient)
Nitrogen
Phosphorus
Nutrients (Ecology)
(c) The Society for Freshwater Science, 2015
Article
info:eu-repo/semantics/publishedVersion
The University of Chicago Press
         

Show full item record

Related documents

Other documents of the same author

Sabater i Comas, Francesc; Butturini, Andrea; Martí, Eugènia; Muñoz Gràcia, Isabel; Romaní i Cornet, Anna M.; Wray, Joanne; Sabater, Sergi
Medici, C.; Bernal Berenguer, Susana; Butturini, Andrea; Sabater i Comas, Francesc; Martin, A.; Wade, A.J.; Frances, F.
Acuña i Salazar, Vicenç; Schiller Calle, Daniel von; García-Galán, Maria Jesús; Rodríguez Mozaz, Sara; Corominas Tabares, Lluís; Petrović, Mira
Chang, C.T.; Sabaté i Jorba, Santi; Sperlich, D.; Poblador Ibáñez, Silvia; Sabater i Comas, Francesc; Gracia, Carles
 

Coordination

 

Supporters