Browsing by Subject "Rivers"

Now showing 1 - 2 of 2
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    Floodplain preconditioning of leaf litter modulates the subsidy of terrestrial C and nutrients in fluvial ecosystems
    (Springer, 2020-05-14) Campo, Rubén del; Martí, Eugènia; Bastias, Elliot; González Barberá, Gonzalo; Sánchez Montoya, María del Mar; Gómez Cerezo, Rosa María; Ecología e Hidrología
    Leaf litter can be retained in floodplains for several months before it enters rivers as lateral inputs. During this period, the environmental conditions on the floodplain can alter leaf litter chemistry and, consequently, affect its subsequent processing in the river. We analysed the effect of contrasting floodplain conditions on the chemical composition of leaf litter and its leachates, and how this affected their biodegradability and processing in rivers. To do so, we placed reed leaf litter (Phragmites australis) in open- and closed-canopy habitats of three floodplain sites with contrasting climates (semiarid Mediterranean, humid Mediterranean and continental) for 105 days. We then used litterbags in a river to examine the decomposition of preconditioned leaf litter in comparison with a control (nonpreconditioned litter), and laboratory assays to examine the biodegradation of their leachates. Contrasting conditions on the floodplain prompted differences in the nutrient content of leaf litter among floodplain sites. Preconditioning caused a generalized decline in the C content and an increase in the lignin content of leaf litter. Even so, preconditioning did not affect litter decomposition rates in the river, although it did reduce decomposition efficiency and biodegradability of leachates. Shredder colonization of litter was variable and generally higher on preconditioned litter, but not significantly so. Different floodplain conditions had no influence on the aquatic processing of preconditioned litter. Our results demonstrate that the retention of leaf litter in terrestrial environments can affect C budgets of fluvial ecosystems and the recipient food web by reducing the input and the biodegradability of C and nutrients.
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    Sobre meandros y cascadas o cómo inundar el correr del río.
    (Ateneo de Estudios Políticos (ACEP), 2024) Cerezo Montoya, Belén; Montero, María Rosario; Sin departamento asociado
    Este ensayo reflexiona sobre la relación entre el agua, el paisaje y su representación, tomando como punto de partida la figura del meandro para explorar la temporalidad del río y cómo interactúa con su entorno. A continuación, este ensayo examina la resistencia de las cascadas a ser capturada en mapas y cómo las imágenes turísticas de las mismas producidas en Chile durante la dictadura, desviaron la atención de los excesos políticos. Asimismo, las fotografías de las cascadas revelan una tensión entre el deseo de congelar el movimiento del agua y su continuo flujo, lo que pone en cuestión la percepción del agua como un recurso gestionable y estático. A partir de estas imágenes y conceptos, el ensayo critica la visión utilitaria del agua y propone un enfoque que la reconoce como parte integral de lo social, expandiendo así la comprensión a un ciclo hidrosocial que desafía las simplificaciones científicas hegemónicas.