title: Sediment cores from kettle holes in NE Germany reveal recent impacts of agriculture.
abstract: Glacial kettle holes in young moraine regions receive abundant terrigenous material from their closed catchments. Core chronology and sediment accumulation were determined for two semi-permanent kettle holes, designated RG and KR, on arable land close to the villages of Rittgarten and Kraatz, respectively, in Uckermark, NE Germany. Core dating ((210)Pb, (137)Cs) revealed variable sediment accretion rates through time (RG 0.4-23.1 mm a(-1); KR 0.2-35.5 mm a(-1)), with periods of high accumulation corresponding to periods of intensive agricultural activity and consequent erosional inputs from catchments. Sediment composition (C, N, P, S, K, Ca, Fe, Mn, Zn, Cu, Mo, Pb, Cd, Zr) was used to determine sediment source and input processes. At RG, annual P input increased from 0.65 kg ha(-1) in the early nineteenth century to 1.67 kg ha(-1) by 2013. At KR, P input increased from 0.6 to 4.1 kg ha(-1) over the last century. There was a concurrent increase in Fe input in both water bodies. Thus, Fe/P ratios showed no temporal trend and did not differ between RG (18.5) and KR (18.4), indicating similar P mobility. At RG, the S/Fe ratio increased from 0.4 to 2.3, indicating more iron sulphides and thus higher P availability, coinciding with high coverage of duckweed (Spirodela polyrhiza (L.)) and soft hornwort (Ceratophyllum submersum L.). At KR, however, this ratio remained low and relatively unchanged (0.3 ± 0.4), indicating more efficient Fe-P binding and lower hydrophyte productivity. Trends in sediment composition indicate a shift towards eutrophication in both kettle holes, but with differences in timing and magnitude. Other morphologically similar kettle holes in NE Germany that are prone to erosion could have been similarly impacted but may differ in the extent of sediment infilling and degradation of their ecological functions.
authors.affiliation: Leibniz Centre for Agricultural Landscape Research, Institute of Landscape Hydrology, Eberswalder Straße 84, 15374, Müncheberg, Germany. Andreas.Kleeberg@landeslabor-bbb.de.|Present address: Department Geology, Soil, Waste, State Laboratory Berlin-Brandenburg, Stahnsdorfer Damm 77, 14532, Kleinmachnow, Germany. Andreas.Kleeberg@landeslabor-bbb.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kleeberg
authors.affiliation: Leibniz Centre for Agricultural Landscape Research, Institute of Landscape Hydrology, Eberswalder Straße 84, 15374, Müncheberg, Germany.|Present address: Department Geosciences, Institute of Geographical Sciences, Freie Universität Berlin, Malteserstr. 74-100, 12249, Berlin, Germany.
authors.forename: Marielle
authors.initials: M
authors.lastname: Neyen
authors.affiliation: Federal Office for Radiation Protection, Köpenicker Allee 120, 10318, Berlin, Germany.
authors.forename: Uwe-Karsten
authors.initials: UK
authors.lastname: Schkade
authors.affiliation: Leibniz Centre for Agricultural Landscape Research, Institute of Landscape Hydrology, Eberswalder Straße 84, 15374, Müncheberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kalettka
authors.affiliation: Leibniz Centre for Agricultural Landscape Research, Institute of Landscape Hydrology, Eberswalder Straße 84, 15374, Müncheberg, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lischeid
mesh_terms: D000383:Agriculture; D002244:Carbon / Q000032:analysis; D005068:Eutrophication; D055593:Geological Phenomena; D005858:Germany; D008670:Metals / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D013455:Sulfur / Q000032:analysis
chemical_list: D008670:Metals; D010758:Phosphorus; D013455:Sulfur; D002244:Carbon; D009584:Nitrogen
keywords: Agriculture; Depressional wetlands; Eutrophication history; Metals; Phosphorus; Radioisotopic dating; Sediment accretion