title: Water level changes affect carbon turnover and microbial community composition in lake sediments.
abstract: Due to climate change, many lakes in Europe will be subject to higher variability of hydrological characteristics in their littoral zones. These different hydrological regimes might affect the use of allochthonous and autochthonous carbon sources. We used sandy sediment microcosms to examine the effects of different hydrological regimes (wet, desiccating, and wet-desiccation cycles) on carbon turnover. (13)C-labelled particulate organic carbon was used to trace and estimate carbon uptake into bacterial biomass (via phospholipid fatty acids) and respiration. Microbial community changes were monitored by combining DNA- and RNA-based real-time PCR quantification and terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA. The shifting hydrological regimes in the sediment primarily caused two linked microbial effects: changes in the use of available organic carbon and community composition changes. Drying sediments yielded the highest CO2 emission rates, whereas hydrological shifts increased the uptake of allochthonous organic carbon for respiration. T-RFLP patterns demonstrated that only the most extreme hydrological changes induced a significant shift in the active and total bacterial communities. As current scenarios of climate change predict an increase of drought events, frequent variations of the hydrological regimes of many lake littoral zones in central Europe are anticipated. Based on the results of our study, this phenomenon may increase the intensity and amplitude in rates of allochthonous organic carbon uptake and CO2 emissions.
authors.affiliation: Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Weise
authors.affiliation: Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Ulrich
authors.affiliation: Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany.
authors.forename: Matilde
authors.initials: M
authors.lastname: Moreano
authors.affiliation: Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany Swiss Federal Research Institute WSL, Zürcherstr. 111, CH-8903 Birmensdorf, Switzerland Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), 14195 Berlin, Germany.
authors.forename: Arthur
authors.initials: A
authors.lastname: Gessler
authors.affiliation: Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany.
authors.forename: Zachary E
authors.initials: ZE
authors.lastname: Kayler
authors.affiliation: University of California, Department of Viticulture and Enology, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Steger
authors.affiliation: INRA, Centre de Nancy Lorraine, UR 1138, Biogéochimie des Ecosystèmes Forestiers (BEF), Labex ARBRE, 54280 Champenoux, France.
authors.forename: Bernd
authors.initials: B
authors.lastname: Zeller
authors.affiliation: TU Chemnitz, Department of Psychology, Research Methods and Evaluation, 09107 Chemnitz, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Rudolph
authors.affiliation: Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Department of Chemical Analytics and Biogeochemistry Müggelseedamm 310, D-12587 Berlin, Germany.
authors.forename: Jelena
authors.initials: J
authors.lastname: Knezevic-Jaric
authors.affiliation: Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg, Institute for Landscape Biogeochemistry, Eberswalderstr. 84, 15374 Müncheberg, Germany Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Department of Chemical Analytics and Biogeochemistry Müggelseedamm 310, D-12587 Berlin, Germany premke@igb-berlin.de.
authors.forename: Katrin
authors.initials: K
authors.lastname: Premke
mesh_terms: D039903:Actinobacteria / Q000145:classification / Q000378:metabolism*; D001105:Archaea / Q000145:classification / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D057486:Carbon Cycle; D057231:Climate Change; D003890:Desiccation; D005060:Europe; D005227:Fatty Acids / Q000378:metabolism; D019015:Geologic Sediments / Q000382:microbiology*; D060106:Lakes / Q000382:microbiology*; D010100:Oxygen / Q000378:metabolism; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; D002244:Carbon; D010100:Oxygen
keywords: carbon dioxide emission; keeling plot; phospholipid fatty acids; stable isotope; water level changes