INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
artículos
Título:
Seasonal weather effects on hydrology drive the metabolism of non-forest lowland streams
Autor/es:
LEGGIERI, LEONARDO RAMON; FEIJOO CLAUDIA SILVINA; GIORGI, ADONIS; FERREIRO NICOLAS ANDRES; ACUÑA VICENÇ
Revista:
HYDROBIOLOGIA
Editorial:
SPRINGER
Referencias:
Lugar: Bruselas; Año: 2013 vol. 716 p. 47 - 58
ISSN:
0018-8158
Resumen:
Weather variations change stream hydrological conditions, affecting the stream function. A seasonal study in three well-conserved first-order Pampean streams was carried out to test the hypothesis that rainfalls are the main drivers of whole-stream metabolism, through their effects on hydrology. We estimated the stream metabolism and metabolic contribution of six relevant communities (angiosperms, macroalgae, seston, epiphyton, epipelon,and hyporheos) during late spring, summer, and winter and examined the relation between gross primary production (GPP) and photosynthetic active radiation (PAR). Our results showed that the decrease in available streambed light due to the dissolved organic carbon after rainfalls was the main factor related to the decrease in the ecosystem and community metabolisms. For instance, GPP oscillated from *10 gO2 m-2 d-1 in early spring (low flows) to *3 gO2 m-2 d-1 in summer (high flows). Ecosystem respiration (ER) was less sensitive than GPP to rainfalls due to the increase of hyporheic respiration. Rainfalls also caused a significant loss of downstream macroalgal biomass. At a day scale, the high PAR of late spring and summer saturated GPP during the afternoon, and the low temperature of winter mornings constrained GPP. Hence, the knowledge of weather changes is key to understanding the main hydrological drivers of stream function.