title: Input, behaviour and distribution of multiple elements in abiotic matrices along a transect within the Okavango Delta, northern Botswana.
abstract: Wetlands fed by rivers can be a sink for elements depending on elemental concentrations, wetland hydrology, geochemistry, vegetation and climate. In the case of the Okavango Delta, northern Botswana, the outflow discharge is a small fraction (2-5%) of the inflow. This has strong potential consequences for the Delta, as it strongly affects element cycling and storage within the Delta. We estimated the inputs, behaviour and distribution of multiple elements along a longitudinal transect within the Okavango Delta, to show potential effects of retention mechanisms of different elements. High annual element input is rather attributed to discharge than to the concentration within the water, which is generally extremely low. We observed minimal enrichment of the elements within the water pathway along the transect from inflow to outlets, implying that element output is negligible. For most elements, we observed a high correlation between storage and sediment organic matter content. The organic matter content within the sediments was higher in the vegetated sediments than in non-vegetated sediments (factor ∼ 10), and a similar trend was found for most elements. In conclusion, organic matter dominated in sediments from vegetated plots and thus plays an important role in retaining the elements within the sediments of the Delta. This finding has major implications for e.g. planning constructed wetlands for water purification or element retention especially in areas with high evapotranspiration.
authors.affiliation: Institute of General Ecology and Environmental Protection, Technische Universität Dresden, 01062, Dresden, Germany. Joerg.Schaller@uni-bayreuth.de.|Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BayCEER), University Bayreuth, Universitätsstraße 30, 95447, Bayreuth, Germany. Joerg.Schaller@uni-bayreuth.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Schaller
authors.affiliation: Department of Biology, University of Antwerp, Campus DrieEiken, Universiteitsplein 1C, 2610, Wilrijk, Belgium.
authors.forename: Jonas
authors.initials: J
authors.lastname: Schoelynck
authors.affiliation: Okavango Research Institute, University of Botswana, Private Bag 285, Maun, Botswana.
authors.forename: Mike
authors.initials: M
authors.lastname: Murray-Hudson
authors.affiliation: Department of Geology, Lund University, Sölvegaten 12, Lund, Sweden.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Frings
authors.affiliation: Department of Biology, University of Antwerp, Campus DrieEiken, Universiteitsplein 1C, 2610, Wilrijk, Belgium.
authors.forename: Dimitri
authors.initials: D
authors.lastname: van Pelt
authors.affiliation: State Reservoir Administration of Saxony, Research Laboratory Paulsdorf, Talsperrenstraße 42, 01744, Dippoldiswalde, Germany.
authors.forename: Tilo
authors.initials: T
authors.lastname: Hegewald
authors.affiliation: Okavango Research Institute, University of Botswana, Private Bag 285, Maun, Botswana.
authors.forename: Keotshephile
authors.initials: K
authors.lastname: Mosimane
authors.affiliation: Okavango Research Institute, University of Botswana, Private Bag 285, Maun, Botswana.
authors.forename: Mangaliso
authors.initials: M
authors.lastname: Gondwe
authors.affiliation: Okavango Research Institute, University of Botswana, Private Bag 285, Maun, Botswana.|Climate Systems Analysis Group, University of Cape Town, Cape Town, South Africa.
authors.forename: Piotr
authors.initials: P
authors.lastname: Wolski
authors.affiliation: Department of Biology, University of Antwerp, Campus DrieEiken, Universiteitsplein 1C, 2610, Wilrijk, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Meire
authors.affiliation: Department of Biology, University of Antwerp, Campus DrieEiken, Universiteitsplein 1C, 2610, Wilrijk, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Struyf
mesh_terms: D001902:Botswana; D002980:Climate; D004784:Environmental Monitoring; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical
keywords: Aquatic ecosystem; Carbon pools; Element accumulation; Macrophytes; Organic rich sediments; Wetland