TY - GEN A1 - Risse-Buhl, Ute A1 - Herrmann, Martina A1 - Lange, Patricia A1 - Akob, Denise M. A1 - Pizani, Natalia A1 - Schönborn, Wilfried A1 - Totsche, Kai Uwe A1 - Küsel, Kirsten T1 - Phagotrophic protist diversity in the groundwater of a karstified aquifer - morphological and molecular analysis T2 - Journal of Eukaryotic Microbiology Y1 - 2013 U6 - https://doi.org/10.1111/jeu.12054 SN - 1550-7408 VL - 60 IS - 5 SP - 467 EP - 479 ER - TY - GEN A1 - Risse-Buhl, Ute A1 - Hagedorn, Frank A1 - Dümig, Alexander A1 - Gessner, Mark O. A1 - Schaaf, Wolfgang A1 - Nii-Annang, Seth A1 - Gerull, Linda A1 - Mutz, Michael T1 - Dynamics, chemical properties and bioavailability of DOC in an early successional catchment T2 - Biogeosciences Y1 - 2013 U6 - https://doi.org/doi:10.5194/bg-10-4751-2013 SN - 1726-4189 VL - 10 SP - 4751 EP - 4765 ER - TY - GEN A1 - Risse-Buhl, Ute A1 - Hagedorn, Frank A1 - Dümig, Alexander A1 - Gessner, Mark O. A1 - Schaaf, Wolfgang A1 - Nii-Annang, Seth A1 - Gerull, Linda A1 - Mutz, Michael T1 - Dynamics, chemical properties and bioavailability of DOC in an early successional catchment T2 - Biogeosciences Discussion KW - DOC KW - bioavailability Y1 - 2013 SN - 1810-6285 VL - 10 IS - 1 SP - 1011 EP - 1049 ER - TY - CHAP A1 - Risse-Buhl, Ute A1 - Hagedorn, Frank A1 - Dümig, Alexander A1 - Gessner, Mark O. A1 - Schaaf, Wolfgang A1 - Nii-Annang, Seth A1 - Gerull, Linda A1 - Mutz, Michael ED - Jeltsch, Florian ED - Joshi, Jasmin T1 - Dynamics, chemical properties and bioavailability of DOC in an early successional catchment T2 - GfÖ 43rd Annual Meeting, Building bridges in ecology, linking systems, scales and disciplines, September 9 to 13, 2013, Potsdam, Germany N2 - The dynamics of dissolved organic carbon (DOC) have been intensively studied in mature ecosystems, but little is known about DOC dynamics and the significance of DOC as a substrate for microbial activity in early-successional catchments. We determined the concentration, chemical composition, radiocarbon age, and bioavailability of DOC along the hydrological flow path from soil solution to a downstream pond in a recently constructed catchment (Chicken Creek Catchment, Germany). Soil solution, upwelling ground water, subsurface water in an alluvial fan, and pond water all had high DOC concentrations (averaged 6.0 – 11.6 mg DOC L‐1), despite small carbon stocks in either vegetation or soil of the catchment. The mean 14C age of DOC in upwelling ground water was 2600 to 2800 years. Solid-state CPMAS 13C NMR revealed a higher proportion of aromatic compounds (32%) and a lower proportion of carbohydrates (33%) in upwelling ground water compared to pond water (18% and 45%, respectively). 14C age and 13C NMR spectra suggest that DOC was partly mobilized from charred organic matter inherent in the Quaternary substrate. In a 70-days incubation experiment, 20% of the total DOC was found to be bioavailable, irrespective of the water type. Origin of the microbial communities within the catchment (enriched from soil, stream sediment or pond water) had only marginal effects on overall DOC utilization. Overall, our data suggest that both recent and old DOC support microbial activity during early ecosystem succession, although a large fraction of the DOC is recalcitrant and eventually exported from the catchment once it has been mobilized. Y1 - 2013 SP - S. 377 PB - Gesellschaft für Ökologie CY - Berlin ER -