Show simple item record Mladenov, N. McKnight, D.M. Wolski, P. Ramberg, L. 2010-06-25T10:19:09Z 2010-06-25T10:19:09Z 2005
dc.identifier.citation Mladenov, N. et al. (2005) Effects of annual flooding on dissolved organic carbon dynamics within a pristine wetland, the Okavango Delta, Botswana, Wetlands, Vol. 25, No. 3, pp. 622–638 en_US
dc.identifier.issn 0923-4861
dc.description.abstract In the Okavango Delta in Botswana, dissolved organic matter (DOM) transport is controlled by the slow movement of an annual flood ‘pulse’ across permanently and seasonally flooded wetlands, known respectively as the Permanent Swamp and Seasonal Swamp. We studied temporal and spatial variations in fluorescence index (FI) and specific UV absorbance (SUVA) of DOM to identify DOM sources and fate during the flood. Dissolved organic carbon (DOC) concentrations ranged from 2 to 25 mg C L21 in channels of the Delta, with seasonal floodplains having consistently higher concentrations. Chemical indices, such as DOC concentrations, conductivity, specific UV absorbance (SUVA), fluorescence, total dissolved nitrogen, and chlorophyll a, were analyzed for channel and floodplain sites in the Seasonal Swamp. DOC concentrations increased during the rising limb of the flood in the Seasonal Swamp. SUVA of whole water samples and fluorescence index (FI) of fulvic acids isolated from channel and floodplain sites changed in a manner indicating the release of DOM by leaching of plant litter during the flood. After the flood receded, DOC concentrations and fulvic acid content decreased, and microbially-derived sources of organic matter dominated. Along two river reaches, measuring over 400 km each, variations in DOC concentrations were primarily due to geomorphology, with the effects of the annual flood overprinted atop the spatial controls. Increasing downstream DOC concentrations were found to be a product of inundation of DOC-rich seasonal floodplains and evaporation-enriched waters downstream. Increasing SUVA, dissolved nitrogen, and fulvic acid content, and decreasing FI downstream suggested microbial processing of terrestrial DOM and possible release of nutrients incorporated in the DOM. en_US
dc.language.iso en en_US
dc.publisher The Society of Wetland Scientists en_US
dc.subject DOC en_US
dc.subject Dissolved organic carbon en_US
dc.subject Flood en_US
dc.subject Swamp en_US
dc.subject Wetland en_US
dc.subject Flood-pulse en_US
dc.subject Flourescence en_US
dc.subject Absorbance en_US
dc.subject Conductivity en_US
dc.subject Fluvic en_US
dc.subject Nutrient en_US
dc.title Effects of annual flooding on dissolved organic carbon dynamics within a pristine wetland, the Okavango Delta, Botswana en_US
dc.type Published Article en_US

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