Groundwater phosphate dynamics in a river riparian zone: effects of hydrologic flowpaths, lithology and redox chemistry

Groundwater-induced redox-gradients control soil properties and phosphorus availability across four headwater wetlands, New York, USA

“…Because these processes are thermodynamically more favorable than formation of calcium carbonate precipitates, these processes will predominate even when pore water is supersaturated with respect to calcite minerals (Golterman 1988;Wilson and Fitter 1984). Consistent with previous studies of organic-rich riparian wetland soils (Carlyle and Hill 2001), we found that redox conditions and the associated Fe-S reactions most strongly influenced internal P dynamics. Phosphorus availability increased with total soil S, Fe, and P at sampling locations under sub-oxic conditions.…”

“…Buffered redox conditions sustained by groundwater supply of terminal electron acceptors (Drever 1988;Boomer and Bedford 2008) and consequent effects on iron-sulfur reactions could play a more prominent role than pH-controls in regulating P availability across fens (Carlyle and Hill 2001;Lamers et al 2002;Lucassen et al 2005;Smolders et al 2006). In particular, influx of sulfate (SO 4 2-)-enriched water to organic-rich wetlands and subsequent reduction processes can enhance ferric iron (Fe 3? )…”

Subsurface Mobilization of Phosphorus in an Agricultural Riparian Zone in Response to Flooding from an Upstream Reservoir

“…However, in some hydrogeological settings, shallow aquifers have been recognized as an important P transport pathway to streams from agricultural lands (Vellidis et al, 2003;Ho and Suprihanto, 1995;Banaszuk et al, 2005). Riparian zones can supply P to surface water via shallow groundwater transport where well-organized hydrologic flow pathways cause water to interact with environments of different redox status and lithology (Roden and Edmonds, 1997;Carlyle and Hill, 2001;Bridgham et al, 2001). Most previous studies on the transfer of agriculturallyderived groundwater P in riparian areas have focused mainly on the upland-riparian interface (Osborne and Kovacic, 1993;Mander et al, 1997;Snyder et al, 1998;Hoffmann et al, 2006;Carlyle and Hill, 2001) and few studies have examined P mobilization in shallow groundwater systems at the stream-riparian interface (Stainton, 2000;Thoms et al, 2000).…”

“…Riparian zones can supply P to surface water via shallow groundwater transport where well-organized hydrologic flow pathways cause water to interact with environments of different redox status and lithology (Roden and Edmonds, 1997;Carlyle and Hill, 2001;Bridgham et al, 2001). Most previous studies on the transfer of agriculturallyderived groundwater P in riparian areas have focused mainly on the upland-riparian interface (Osborne and Kovacic, 1993;Mander et al, 1997;Snyder et al, 1998;Hoffmann et al, 2006;Carlyle and Hill, 2001) and few studies have examined P mobilization in shallow groundwater systems at the stream-riparian interface (Stainton, 2000;Thoms et al, 2000). An improved understanding of the spatial and temporal conditions under which riparian wetlands act as sources or sinks of P is needed, and more research is required to better understand the physical, chemical and biological processes that govern the rate and magnitude of P transport in shallow groundwater systems (Flores-Lopez et al, 2005).…”

Modificación del índice de calidad de riberas: Inclusión del componente social en la evaluación de la calidad ribereña de la microcuenca del río Burío-Quebrada Seca

“…Por ejemplo, estas comunidades vegetales sirven de filtro entre el río y los ambientes adyacentes, lo que impide o retarda el flujo de la escorrentía hacia el cauce, la cual en muchas ocasiones trae consigo agroquímicos, nutrientes (principalmente nitrógeno y fósforo) y productos orgánicos provenientes de las actividades antropogénicas y de los cambios en los usos del suelo (Burt et al, 2002;Carlyle y Hill, 2001;Dhondt, Boeckx, Verdehoest, Hofman y Van Cleemput, 2006;Granados et al, 2006). También, permite amortiguar los procesos de sedimentación de los lechos de los ríos y de erosión en las riberas (González y García, 1998;Pinay y Decamps, 1988;Timoney, Peterson y Wein, 1997), poseen una gran influencia sobre la calidad del agua y del ecosistema fluvial, debido a que la vegetación, principalmente la arbórea, sombrea el cauce del sistema acuático y contribuye al control del nivel de insolación y del régimen de temperaturas de las aguas; además, aumenta la cantidad de oxígeno disuelto, regula la entrada de luz al sistema y retarda el crecimiento de las algas (Ahola, 1990y Dawson y Haslam, 1983, citados por González y García, 1998Granados et al, 2006).…”