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  • 1.
    Abbasi, Mona
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Peacock, Mike
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Uppsala, Sweden.;Univ Liverpool, Sch Environm Sci, Dept Geog & Planning, Liverpool, England..
    Drakare, Stina
    Swedish Univ Agr Sci SLU, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    Hawkes, Jeffrey
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Jakobsson, Elizabeth
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Kothawala, Dolly
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Water residence time is an important predictor of dissolved organic matter composition and drinking water treatability2024In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 260, article id 121910Article in journal (Refereed)
    Abstract [en]

    Freshwater ecosystems are critical resources for drinking water. In recent decades, dissolved organic matter (DOM) inputs into aquatic systems have increased significantly, particularly in central and northern Europe, due to climatic and anthropogenic drivers. The associated increase in dissolved organic carbon (DOC) concentration can change lake ecosystem services and adversely affect drinking water treatment processes. In this study, we examined spatial and temporal patterns of DOM treatability with granular activated carbon (GAC) and biological reactivity based on 14-day bacterial respiration incubations at 11 sites across Mälaren during six-time points between July 2019 and February 2021. Mälaren is the third largest lake in Sweden and provides drinking water for over 2 million people including the capital city Stockholm. In our spatio-temporal analysis, we assessed the influence of phytoplankton abundance, water chemistry, runoff, and climate on DOM composition, GAC removal efficiency, and biological reactivity. Variations in DOM composition were characterized using optical measurements and Orbitrap mass spectrometry. Multivariate statistical analyses indicated that DOM produced during warmer months was easier to remove by GAC. Removal efficiency of GAC varied from 41 to 87 %, and the best predictor of treatability using mass spectrometry was double bond equivalents (DBE), while the best optical predictors were specific UV absorbance (SUVA), and freshness index. The oxygen consumption rate (k) from the bacterial respiration incubations ranged from 0.04 to 0.71 d−1 and higher in warmer months and at deeper basins and was associated with more aliphatic and fresh DOM. The three deepest lake basins with the longest water residence time (WRT) were temporally the most stable in terms of DOM composition and had the highest DOC removal efficiency and k rates. DOM composition in these three lake basins was optically clearer than in basins located closer to terrestrial inputs and had a signature suggesting it was derived from in-lake processes including phytoplankton production and bacterial processing of terrestrial DOM. This means that with increasing WRT, DOM derived from terrestrial sources shifts to more aquatically produced DOM and becomes easier to remove with GAC. These findings indicate WRT can be highly relevant in shaping DOM composition and thereby likely to affect its ease of treatability for drinking water purposes.

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  • 2.
    Abbott, Benjamin W.
    et al.
    Univ Rennes 1, OSUR, CNRS, UMR ECOBIO 6553, F-35014 Rennes, France.;Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Jones, Jeremy B.
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Schuur, Edward A. G.
    No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    Chapin, F. Stuart, III
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Bowden, William B.
    Univ Vermont, Rubenstein Sch Environm & Nat Resources, Burlington, VT 05405 USA..
    Bret-Harte, M. Syndonia
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Epstein, Howard E.
    Univ Virginia, Dept Environm Sci, Charlottesville, VA 22903 USA..
    Flannigan, Michael D.
    Univ Alberta, Dept Renewable Resources, Edmonton, AB T6G 2M7, Canada..
    Harms, Tamara K.
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA.;Univ Alaska Fairbanks, Dept Biology& Wildlife, Fairbanks, AK USA..
    Hollingsworth, Teresa N.
    Univ Alaska Fairbanks, PNW Res Stn, USDA Forest Serv, Fairbanks, AK USA..
    Mack, Michelle C.
    No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    McGuire, A. David
    Univ Alaska Fairbanks, Alaska Cooperat Fish & Wildlife Res Unit, US Geol Survey, Anchorage, AK USA..
    Natali, Susan M.
    Woods Hole Res Ctr, Woods Hole, MA USA..
    Rocha, Adrian V.
    Univ Notre Dame, Dept Biol Sci, Notre Dame, IN 46556 USA.;Univ Notre Dame, Environm Change Initiat, Notre Dame, IN 46556 USA..
    Tank, Suzanne E.
    Univ Alberta, Dept Biol Sci, Edmonton, AB T6G 2M7, Canada..
    Turetsky, Merritt R.
    Univ Guelph, Dept Integrat Biol, Guelph, ON N1G 2W1, Canada..
    Vonk, Jorien E.
    Vrije Univ Amsterdam, Dept Earth Sci, Amsterdam, Netherlands..
    Wickland, Kimberly P.
    US Geol Survey, Natl Res Program, Boulder, CO USA..
    Aiken, George R.
    US Geol Survey, Natl Res Program, Boulder, CO USA..
    Alexander, Heather D.
    Mississippi State Univ, Forest & Wildlife Res Ctr, Mississippi State, MS 39762 USA..
    Amon, Rainer M. W.
    Texas A&M Univ, Galveston, TX USA..
    Benscoter, Brian W.
    Florida Atlantic Univ, Boca Raton, FL 33431 USA..
    Bergeron, Yves
    Univ Quebec Abitibi Temiscamingue, Forest Res Inst, Rouyn Noranda, PQ, Canada..
    Bishop, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL. wedish Univ Agr Sci, Dept Aquat Sci & Assessment, S-90183 Umea, Sweden..
    Blarquez, Olivier
    Univ Montreal, Dept Geog, Montreal, PQ H3C 3J7, Canada..
    Bond-Lamberty, Ben
    Pacific NW Natl Lab, Richland, WA 99352 USA..
    Breen, Amy L.
    Univ Alaska Fairbanks, Int Arctic Res Ctr, Scenarios Network Alaska & Arctic Planning, Fairbanks, AK USA..
    Buffam, Ishi
    Univ Cincinnati, Cincinnati, OH 45221 USA..
    Cai, Yihua
    Xiamen Univ, State Key Lab Marine Environm Sci, Xiamen, Peoples R China..
    Carcaillet, Christopher
    Ecole Prat Hautes Etud, UMR5023, CNRS Lyon 1, Lyon, France..
    Carey, Sean K.
    McMaster Univ, Hamilton, ON L8S 4L8, Canada..
    Chen, Jing M.
    Univ Toronto, Toronto, ON M5S 1A1, Canada..
    Chen, Han Y. H.
    Lakehead Univ, Fac Nat Resources Management, Thunder Bay, ON P7B 5E1, Canada..
    Christensen, Torben R.
    Lund Univ, Arctic Res Ctr, S-22100 Lund, Sweden.;Aarhus Univ, DK-8000 Aarhus C, Denmark..
    Cooper, Lee W.
    Univ Maryland, Ctr Environm Sci, Bethesda, MD USA..
    Cornelissen, J. Hans C.
    Vrije Univ Amsterdam, Syst Ecol, Amsterdam, Netherlands..
    de Groot, William J.
    Nat Resources Canada, Canadian Forest Serv, Toronto, ON, Canada..
    DeLuca, Thomas H.
    Univ Washington, Sch Environm & Forest Sci, Seattle, WA 98195 USA..
    Dorrepaal, Ellen
    Umea Univ, Dept Ecol & Environm Sci, Climate Impacts Res Ctr, S-90187 Umea, Sweden..
    Fetcher, Ned
    Wilkes Univ, Inst Environm Sci & Sustainabil, Wilkes Barre, PA 18766 USA..
    Finlay, Jacques C.
    Univ Minnesota, Dept Ecol Evolut & Behav, Minneapolis, MN 55455 USA..
    Forbes, Bruce C.
    Univ Lapland, Arctic Ctr, Rovaniemi, Finland..
    French, Nancy H. F.
    Michigan Technol Univ, Michigan Tech Res Inst, Houghton, MI 49931 USA..
    Gauthier, Sylvie
    Nat Resources Canada, Canadian Forest Serv, Laurentian Forestry Ctr, Toronto, ON, Canada..
    Girardin, Martin P.
    Nat Resources Canada, Canadian Forest Serv, Laurentian Forestry Ctr, Toronto, ON, Canada..
    Goetz, Scott J.
    Woods Hole Res Ctr, Woods Hole, MA USA..
    Goldammer, Johann G.
    Max Planck Inst Chem, Global Fire Monitoring Ctr, Berlin, Germany..
    Gough, Laura
    Towson Univ, Dept Biol Sci, Towson, MD USA..
    Grogan, Paul
    Queens Univ, Dept Biol, Kingston, ON K7L 3N6, Canada..
    Guo, Laodong
    Univ Wisconsin Milwaukee, Sch Freshwater Sci, Milwaukee, WI USA..
    Higuera, Philip E.
    Univ Montana, Dept Ecosyst & Conservat Sci, Missoula, MT 59812 USA..
    Hinzman, Larry
    Univ Alaska Fairbanks, Fairbanks, AK USA..
    Hu, Feng Sheng
    Univ Illinois, Dept Plant Biol, Chicago, IL 60680 USA.;Univ Illinois, Dept Geol, Chicago, IL 60680 USA..
    Hugelius, Gustaf
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Jafarov, Elchin E.
    Univ Colorado Boulder, Inst Arctic & Alpine Res, Boulder, CO USA..
    Jandt, Randi
    Univ Alaska Fairbanks, Alaska Fire Sci Consortium, Fairbanks, AK USA..
    Johnstone, Jill F.
    Univ Saskatchewan, Dept Biol, Saskatoon, SK S7N 0W0, Canada..
    Karlsson, Jan
    Umea Univ, Dept Ecol & Environm Sci, Climate Impacts Res Ctr, S-90187 Umea, Sweden..
    Kasischke, Eric S.
    Univ Maryland, Dept Geog Sci, Bethesda, MD USA..
    Kattner, Gerhard
    Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, Berlin, Germany..
    Kelly, Ryan
    Neptune & Co Inc, North Wales, PA USA..
    Keuper, Frida
    Umea Univ, Dept Ecol & Environm Sci, Climate Impacts Res Ctr, S-90187 Umea, Sweden.;INRA, AgroImpact UPR1158, New York, NY USA..
    Kling, George W.
    Univ Michigan, Ann Arbor, MI 48109 USA..
    Kortelainen, Pirkko
    Finnish Environm Inst, Helsinki, Finland..
    Kouki, Jari
    Univ Eastern Finland, Sch Forest Sci, Joensuu, Finland..
    Kuhry, Peter
    Stockholm Univ, Dept Phys Geog, Stockholm, Sweden..
    Laudon, Hjalmar
    Swedish Univ Agr Sci, Dept Forest Ecol & Management, S-90183 Umea, Sweden..
    Laurion, Isabelle
    Inst Natl Rech Sci, Ctr Eau Terre Environm, Toronto, ON, Canada..
    Macdonald, Robie W.
    Inst Ocean Sci, Dept Fisheries & Oceans, Toronto, ON, Canada..
    Mann, Paul J.
    Northumbria Univ, Dept Geog, Newcastle Upon Tyne NE1 8ST, Tyne & Wear, England..
    Martikainen, Pertti J.
    Univ Eastern Finland, Dept Environm & Biol Sci, Joensuu, Finland..
    McClelland, James W.
    Univ Texas Austin, Inst Marine Sci, Austin, TX 78712 USA..
    Molau, Ulf
    Univ Gothenburg, Dept Biol & Environm Sci, Gothenburg, Sweden..
    Oberbauer, Steven F.
    Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA..
    Olefeldt, David
    Univ Alberta, Dept Revewable Resources, Edmonton, AB T6G 2M7, Canada..
    Pare, David
    Nat Resources Canada, Canadian Forest Serv, Laurentian Forestry Ctr, Toronto, ON, Canada..
    Parisien, Marc-Andre
    Nat Resources Canada, Canadian Forest Serv, No Forestry Ctr, Toronto, ON, Canada..
    Payette, Serge
    Univ Laval, Ctr Etud Nord, Quebec City, PQ G1K 7P4, Canada..
    Peng, Changhui
    Univ Quebec, Ctr CEF, ESCER, Montreal, PQ H3C 3P8, Canada.;Northwest A&F Univ, Coll Forestry, State Key Lab Soil Eros & Dryland Farming Loess P, Xian, Peoples R China..
    Pokrovsky, Oleg S.
    CNRS, Georesources & Environm, Toulouse, France.;Tomsk State Univ, BIO GEO CLIM Lab, Tomsk, Russia..
    Rastetter, Edward B.
    Marine Biol Lab, Ctr Ecosyst, Woods Hole, MA 02543 USA..
    Raymond, Peter A.
    Yale Univ, Sch Forestry & Environm Studies, New Haven, CT 06520 USA..
    Raynolds, Martha K.
    Univ Alaska Fairbanks, Inst Arctic Biol, Fairbanks, AK USA..
    Rein, Guillermo
    Univ London Imperial Coll Sci Technol & Med, Dept Mech Engn, London SW7 2AZ, England..
    Reynolds, James F.
    Lanzhou Univ, Sch Life Sci, Lanzhou 730000, Peoples R China.;Duke Univ, Nicholas Sch Environm, Durham, NC 27706 USA..
    Robards, Martin
    Arctic Beringia Program, Wildlife Conservat Soc, New York, NY USA..
    Rogers, Brendan M.
    Woods Hole Res Ctr, Woods Hole, MA USA..
    Schaedel, Christina
    No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    Schaefer, Kevin
    Univ Colorado Boulder, Cooperat Inst Res Environm Sci, Natl Snow & Ice Data Ctr, Boulder, CO USA..
    Schmidt, Inger K.
    Univ Copenhagen, Dept Geosci & Nat Resource Management, DK-1168 Copenhagen, Denmark..
    Shvidenko, Anatoly
    Int Inst Appl Syst Anal, A-2361 Laxenburg, Austria.;Sukachev Inst Forest, Moscow, Russia..
    Sky, Jasper
    Cambridge Ctr Climate Change Res, Cambridge, England..
    Spencer, Robert G. M.
    Florida State Univ, Dept Earth Ocean & Atmospher Sci, Tallahassee, FL 32306 USA..
    Starr, Gregory
    Univ Alabama, Dept Biol Sci, Tuscaloosa, AL 35487 USA..
    Striegl, Robert G.
    US Geol Survey, Natl Res Program, Boulder, CO USA..
    Teisserenc, Roman
    Univ Toulouse, CNRS, INPT, ECOLAB,UPS, Toulouse, France..
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Virtanen, Tarmo
    Univ Helsinki, Dept Environm Sci, FIN-00014 Helsinki, Finland..
    Welker, Jeffrey M.
    Univ Alaska Anchorage, Anchorage, AK USA..
    Zimov, Sergei
    Russian Acad Sci, Northeast Sci Stn, Moscow 117901, Russia..
    Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment2016In: Environmental Research Letters, E-ISSN 1748-9326, Vol. 11, no 3, article id 034014Article in journal (Refereed)
    Abstract [en]

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

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  • 3. Abernethy, R.
    et al.
    Weyhenmeyer, Gesa A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Ziese, Markus G.
    State of the Climate in 20172018In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 99, no 8, p. Si-S310Article in journal (Refereed)
  • 4. Abramoff, Rose Z.
    et al.
    Georgiou, Katerina
    Guenet, Bertrand
    Torn, Margaret S.
    Huang, Yuanyuan
    Zhang, Haicheng
    Feng, Wenting
    Jagadamma, Sindhu
    Kaiser, Klaus
    Kothawala, Dolly
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Mayes, Melanie A.
    Ciais, Philippe
    How much carbon can be added to soil by sorption?2021In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 152, no 2-3, p. 127-142Article in journal (Refereed)
    Abstract [en]

    Quantifying the upper limit of stable soil carbon storage is essential for guiding policies to increase soil carbon storage. One pool of carbon considered particularly stable across climate zones and soil types is formed when dissolved organic carbon sorbs to minerals. We quantified, for the first time, the potential of mineral soils to sorb additional dissolved organic carbon (DOC) for six soil orders. We compiled 402 laboratory sorption experiments to estimate the additional DOC sorption potential, that is the potential of excess DOC sorption in addition to the existing background level already sorbed in each soil sample. We estimated this potential using gridded climate and soil geochemical variables within a machine learning model. We find that mid- and low-latitude soils and subsoils have a greater capacity to store DOC by sorption compared to high-latitude soils and topsoils. The global additional DOC sorption potential for six soil orders is estimated to be 107 ± 13 Pg C to 1 m depth. If this potential was realized, it would represent a 7% increase in the existing total carbon stock.

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  • 5.
    Ades, M.
    et al.
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England..
    Adler, R.
    Univ Maryland, College Pk, MD 20742 USA..
    Allan, Rob
    Met Off Hadley Ctr, Exeter, Devon, England..
    Allan, R. P.
    Univ Reading, Reading, Berks, England..
    Anderson, J.
    Hampton Univ, Dept Atmospher & Planetary Sci, Hampton, VA 23668 USA..
    Arguez, Anthony
    NOAA NESDIS Natl Ctr Environm Informat, Asheville, NC USA..
    Arosio, C.
    Univ Bremen, Bremen, Germany..
    Augustine, J. A.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA..
    Azorin-Molina, C.
    Ctr Invest Desertificac Spanish Natl Res Council, Moncada, Valencia, Spain.;Univ Gothenburg, Dept Earth Sci, Reg Climate Grp, Gothenburg, Sweden..
    Barichivich, J.
    Pontificia Univ Catolica Valparaiso, Inst Geog, Valparaiso, Chile..
    Barnes, J.
    NOAA OAR ESRL Global Monitoring Lab, Boulder, CO USA..
    Beck, H. E.
    Princeton Univ, Dept Civil & Environm Engn, Princeton, NJ 08544 USA..
    Becker, Andreas
    Deutsch Wetterdienst, Global Precipitat Climatol Ctr, Offenbach, Germany..
    Bellouin, Nicolas
    Univ Reading, Reading, Berks, England..
    Benedetti, Angela
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England..
    Berry, David I.
    Natl Oceanog Ctr, Southampton, Hants, England..
    Blenkinsop, Stephen
    Newcastle Univ, Sch Engn, Newcastle Upon Tyne, Tyne & Wear, England..
    Bock, Olivier
    Univ Paris, CNRS, Inst Phys Globe Paris, IGN, Paris, France.;IGN, ENSG Geomat, Marne La Vallee, France..
    Bosilovich, Michael G.
    NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD USA..
    Boucher, Olivier
    Sorbonne Univ, Paris, France..
    Buehler, S. A.
    Univ Hamburg, Hamburg, Germany..
    Carrea, Laura
    Univ Reading, Dept Meteorol, Reading, Berks, England..
    Christiansen, Hanne H.
    Univ Ctr Svalbard, Dept Geol, Longyearbyen, Norway..
    Chouza, F.
    CALTECH, Jet Prop Lab, Wrightwood, CA USA..
    Christy, John R.
    Univ Alabama Huntsville, Huntsville, AL USA..
    Chung, E. -S
    Coldewey-Egbers, Melanie
    German Aerosp Ctr DLR Oberpfaffenhofen, Wessling, Germany..
    Compo, Gil P.
    Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.;NOAA Earth Syst Res Lab, Div Phys Sci, Boulder, CO USA..
    Cooper, Owen R.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA.;Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Covey, Curt
    Lawrence Livermore Natl Lab, Livermore, CA 94550 USA..
    Crotwell, A.
    Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Davis, Sean M.
    Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.;NOAA OAR Earth Syst Res Lab, Boulder, CO USA..
    de Eyto, Elvira
    Inst Marine, Furnace, Newport, Ireland..
    de Jeu, Richard A. M.
    VanderSat, B. V.
    DeGasperi, Curtis L.
    King Cty Water & Land Resources Div, Seattle, WA USA..
    Degenstein, Doug
    Univ Saskatchewan, Saskatoon, SK, Canada..
    Di Girolamo, Larry
    Univ Illinois, Champaign, IL USA..
    Dokulil, Martin T.
    Univ Innsbruck, Res Dept Limnol, Innsbruck, Austria..
    Donat, Markus G.
    Barcelona Supercomp Ctr, Barcelona, Spain..
    Dorigo, Wouter A.
    TU Wien Vienna Univ Technol, Dept Geodesy & Geoinformat, Vienna, Austria..
    Dunn, R. J. H.
    Met Off Hadley Ctr, Exeter, Devon, England..
    Durre, Imke
    NOAA NESDIS Natl Ctr Environm Informat, Asheville, NC USA..
    Dutton, Geoff S.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA.;Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Duveiller, G.
    European Commiss, Joint Res Ctr, Ispra, Italy..
    Elkins, James W.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA..
    Fioletov, Vitali E.
    Environm & Climate Change Canada, Toronto, ON, Canada..
    Flemming, Johannes
    European Ctr Medum Range Weather Forecasts, Reading, Berks, England..
    Foster, Michael J.
    Univ Wisconsin Madison, Cooperat Inst Meteorol Satellite Studies, Space Sci & Engn Ctr, Madison, WI USA..
    Frey, Richard A.
    Univ Wisconsin Madison, Cooperat Inst Meteorol Satellite Studies, Space Sci & Engn Ctr, Madison, WI USA..
    Frith, Stacey M.
    Sci Syst & Applicat Inc, Lanham, MD USA.;NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Froidevaux, Lucien
    CALTECH, Jet Prop Lab, Pasadena, CA USA..
    Garforth, J.
    Woodland Trust, Grantham, England..
    Gobron, N.
    European Commiss, Joint Res Ctr, Ispra, Italy..
    Gupta, S. K.
    Sci Syst & Applicat Inc, Hampton, VA USA..
    Haimberger, Leopold
    Univ Vienna, Dept Meteorol & Geophys, Vienna, Austria..
    Hall, Brad D.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA..
    Harris, Ian
    Univ East Anglia, Natl Ctr Atmospher Sci, Norwich, Norfolk, England.;Univ East Anglia, Sch Environm Sci, Climat Res Unit, Norwich, Norfolk, England..
    Heidinger, Andrew K.
    Univ Wisconsin Madison, NOAA NESDIS STAR, Madison, WI USA..
    Hemming, D. L.
    Met Off Hadley Ctr, Exeter, Devon, England.;Univ Birmingham, Birmingham Inst Forest Res, Birmingham, W Midlands, England..
    Ho, Shu-peng (Ben)
    NOAA NESDIS Ctr Satellite Applicat & Res, College Pk, MD USA..
    Hubert, Daan
    Royal Belgian Inst Space Aeron BIRA, Brussels, Belgium..
    Hurst, Dale F.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA.;Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Huser, I.
    Deutsch Wetterdienst, Offenbach, Germany..
    Inness, Antje
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England..
    Isaksen, K.
    Norwegian Meteorol Inst, Oslo, Norway..
    John, Viju
    EUMETSAT, Darmstadt, Germany..
    Jones, Philip D.
    Univ East Anglia, Sch Environm Sci, Climat Res Unit, Norwich, Norfolk, England..
    Kaiser, J. W.
    Deutsch Wetterdienst, Offenbach, Germany..
    Kelly, S.
    Dundalk Inst Technol, Dundalk, Ireland..
    Khaykin, S.
    Sorbonne Univ, CNRS, LATMOS IPSL, UVSQ, Guyancourt, France..
    Kidd, R.
    Earth Observat Data Ctr GmbH, Vienna, Austria..
    Kim, Hyungiun
    Univ Tokyo, Inst Ind Sci, Tokyo, Japan..
    Kipling, Z.
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England..
    Kraemer, B. M.
    IGB Leibniz Inst Freshwater Ecol & Inland Fisheri, Berlin, Germany..
    Kratz, D. P.
    NASA, Langley Res Ctr, Hampton, VA 23665 USA..
    La Fuente, R. S.
    Dundalk Inst Technol, Dundalk, Ireland..
    Lan, Xin
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA.;Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Lantz, Kathleen O.
    NOAA OAR Earth Syst Res Lab, Boulder, CO USA..
    Leblanc, T.
    CALTECH, Jet Prop Lab, Wrightwood, CA USA..
    Li, Bailing
    NASA Goddard Space Flight Ctr, Hydrol Sci Lab, Greenbelt, MD USA.;Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA..
    Loeb, Norman G.
    NASA, Langley Res Ctr, Hampton, VA 23665 USA..
    Long, Craig S.
    NOAA NWS Natl Ctr Environm Predict, College Pk, MD USA..
    Loyola, Diego
    German Aerosp Ctr DLR Oberpfaffenhofen, Wessling, Germany..
    Marszelewski, Wlodzimierz
    Nicolaus Copernicus Univ, Dept Hydrol & Water Management, Torun, Poland..
    Martens, B.
    Univ Ghent, Hydro Climate Extremes Lab, Ghent, Belgium..
    May, Linda
    Ctr Ecol & Hydrol, Edinburgh, Midlothian, Scotland..
    Mayer, Michael
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England.;Univ Vienna, Dept Meteorol & Geophys, Vienna, Austria..
    McCabe, M. F.
    King Abdullah Univ Sci & Technol, Div Biol & Environm Sci & Engn, Thuwal, Saudi Arabia..
    McVicar, Tim R.
    CSIRO Land & Water, Canberra, ACT, Australia.;Australian Res Council Ctr Excellence Climate Ext, Sydney, NSW, Australia..
    Mears, Carl A.
    Remote Sensing Syst, Santa Rosa, CA USA..
    Menzel, W. Paul
    Univ Wisconsin Madison, Space Sci & Engn Ctr, Madison, WI USA..
    Merchant, Christopher J.
    Univ Reading, Dept Meteorol, Reading, Berks, England.;Univ Reading, Natl Ctr Earth Observat, Reading, Berks, England..
    Miller, Ben R.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA.;Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Miralles, Diego G.
    Montzka, Stephen A.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA..
    Morice, Colin
    Met Off Hadley Ctr, Exeter, Devon, England..
    Muhle, Jens
    Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA..
    Myneni, R.
    Boston Univ, Dept Earth & Environm, Boston, MA 02215 USA..
    Nicolas, Julien P.
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England..
    Noetzli, Jeannette
    WSL Inst Snow & Avalanche Res SLF, Davos, Switzerland..
    Osborn, Tim J.
    Univ East Anglia, Sch Environm Sci, Climat Res Unit, Norwich, Norfolk, England..
    Park, T.
    NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.;Bay Area Environm Res Inst, Moffett Field, CA USA..
    Pasik, A.
    TU Wien Vienna Univ Technol, Dept Geodesy & Geoinformat, Vienna, Austria..
    Paterson, Andrew M.
    Ontario Minist Environm & Climate Change, Dorset Environm Sci Ctr, Dorset, ON, Canada..
    Pelto, Mauri S.
    Nichols Coll, Dudley, MA USA..
    Perkins-Kirkpatrick, S.
    Univ New South Wales, Sydney, NSW, Australia..
    Petron, G.
    Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Phillips, C.
    Univ Wisconsin Madison, Dept Atmospher & Ocean Sci, Madison, WI USA..
    Pinty, Bernard
    European Commiss, Joint Res Ctr, Ispra, Italy..
    Po-Chedley, S.
    Lawrence Livermore Natl Lab, Livermore, CA 94550 USA..
    Polvani, L.
    Columbia Univ, New York, NY USA..
    Preimesberger, W.
    TU Wien Vienna Univ Technol, Dept Geodesy & Geoinformat, Vienna, Austria..
    Pulkkanen, M.
    Finnish Environm Inst SYKE, Freshwater Ctr, Helsinki, Finland..
    Randel, W. J.
    Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA..
    Remy, Samuel
    UPMC, Inst Pierre Simon Laplace, CNRS, Paris, France..
    Ricciardulli, L.
    Richardson, A. D.
    No Arizona Univ, Sch Informat Comp & Cyber Syst, Flagstaff, AZ 86011 USA.;No Arizona Univ, Ctr Ecosyst Sci & Soc, Flagstaff, AZ 86011 USA..
    Rieger, L.
    Univ Saskatchewan, Saskatoon, SK, Canada..
    Robinson, David A.
    Rutgers State Univ, Dept Geog, Piscataway, NJ USA..
    Rodell, Matthew
    NASA Goddard Space Flight Ctr, Hydrol Sci Lab, Greenbelt, MD USA..
    Rosenlof, Karen H.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA..
    Roth, Chris
    Univ Saskatchewan, Saskatoon, SK, Canada..
    Rozanov, A.
    Univ Bremen, Bremen, Germany..
    Rusak, James A.
    Ontario Minist Environm & Climate Change, Dorset Environm Sci Ctr, Dorset, ON, Canada..
    Rusanovskaya, O.
    Irkutsk State Univ, Inst Biol, Irkutsk, Russia..
    Rutishauser, T.
    Univ Bern, Inst Geog, Bern, Switzerland.;Univ Bern, Oeschger Ctr, Bern, Switzerland..
    Sanchez-Lugo, Ahira
    NOAA NESDIS Natl Ctr Environm Informat, Asheville, NC USA..
    Sawaengphokhai, P.
    Sci Syst & Applicat Inc, Hampton, VA USA..
    Scanlon, T.
    TU Wien Vienna Univ Technol, Dept Geodesy & Geoinformat, Vienna, Austria..
    Schenzinger, Verena
    Univ Vienna, Dept Meteorol & Geophys, Vienna, Austria..
    Schladow, S. Geoffey
    Univ Calif Davis, Tahoe Environm Res Ctr, Davis, CA 95616 USA..
    Schlegel, R. W.
    Woods Hole Oceanog Inst, Dept Phys Oceanog, Woods Hole, MA 02543 USA..
    Schmid, Martin Eawag
    Swiss Fed Inst Aquat Sci & Technol, Kastanienbaum, Switzerland..
    Selkirk, H. B.
    Univ Space Res Assoc, NASA Goddard Space Flight Ctr, Greenbelt, MD USA..
    Sharma, S.
    York Univ, Toronto, ON, Canada..
    Shi, Lei
    NOAA NESDIS, Natl Ctr Environm Informat, Asheville, NC USA..
    Shimaraeva, S. V.
    Irkutsk State Univ, Inst Biol, Irkutsk, Russia..
    Silow, E. A.
    Irkutsk State Univ, Inst Biol, Irkutsk, Russia..
    Simmons, Adrian J.
    European Ctr Medium Range Weather Forecasts, Reading, Berks, England..
    Smith, C. A.
    Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA..
    Smith, Sharon L.
    Nat Resources Canada, Geol Survey Canada, Ottawa, ON, Canada..
    Soden, B. J.
    Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Key Biscayne, FL USA..
    Sofieva, Viktoria
    Finnish Meteorol Inst, Helsinki, Finland..
    Sparks, T. H.
    Poznan Univ Life Sci, Poznan, Poland..
    Stackhouse, Paul W., Jr.
    NASA, Langley Res Ctr, Hampton, VA 23665 USA..
    Stanitski, D. M.
    NOAA OAR Earth Syst Res Labs, Boulder, CO USA..
    Steinbrecht, Wolfgang
    German Weather Serv DWD, Hohenpeissenberg, Germany..
    Streletskiy, Dimitri A.
    George Washington Univ, Dept Geog, Washington, DC USA..
    Taha, G.
    GESTAR, Columbia, MD USA..
    Telg, Hagen
    Thackeray, S. J.
    Ctr Ecol & Hydrol, Lancaster, England..
    Timofeyev, M. A.
    Irkutsk State Univ, Inst Biol, Irkutsk, Russia..
    Tourpali, Kleareti
    Aristotle Univ Thessaloniki, Thessaloniki, Greece..
    Tye, Mari R.
    Natl Ctr Atmospher Res, Capac Ctr Climate & Weather Extremes, POB 3000, Boulder, CO 80307 USA..
    van der A, Ronald J.
    Royal Netherlands Meteorol Inst, De Bilt, Netherlands..
    van der Schalie, Robin
    van der Schrier, Gerard
    Royal Netherlands Meteorol Inst, De Bilt, Netherlands..
    van der Werf, Guido R.
    Vrije Univ Amsterdam, Amsterdam, Netherlands..
    Verburg, Piet
    Natl Inst Water & Atmospher Res, Hamilton, New Zealand..
    Vernier, Jean-Paul
    NASA, Langley Res Ctr, Hampton, VA 23665 USA..
    Vomel, Holger
    Natl Ctr Atmospher Res, Earth Observing Lab, POB 3000, Boulder, CO 80307 USA..
    Vose, Russell S.
    NOAA NESDIS Natl Ctr Environm Informat, Asheville, NC USA..
    Wang, Ray
    Georgia Inst Technol, Atlanta, GA 30332 USA..
    Watanabe, Shohei G.
    Univ Calif Davis, Tahoe Environm Res Ctr, Davis, CA 95616 USA..
    Weber, Mark
    Univ Bremen, Bremen, Germany..
    Weyhenmeyer, Gesa A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala Univ, Dept Ecol & Genet Limnol, Uppsala, Sweden..
    Wiese, David
    CALTECH, Jet Prop Lab, Pasadena, CA USA..
    Wilber, Anne C.
    Sci Syst & Applicat Inc, Hampton, VA USA..
    Wild, Jeanette D.
    NOAA Climate Predict Ctr, College Pk, MD USA.;Univ Maryland, ESSIC, College Pk, MD 20742 USA..
    Willett, K. M.
    Met Off Hadley Ctr, Exeter, Devon, England..
    Wong, Takmeng
    NASA, Langley Res Ctr, Hampton, VA 23665 USA..
    Woolway, R. Iestyn
    Dundalk Inst Technol, Dundalk, Ireland..
    Yin, Xungang
    NOAA NESDIS Natl Ctr Environm Informat, ERT Inc, Asheville, NC USA..
    Zhao, Lin
    Nanjing Univ Informat Sci & Technol, Sch Geog Sci, Nanjing, Peoples R China..
    Zhao, Guanguo
    Univ Illinois, Champaign, IL USA..
    Zhou, Xinjia
    Ziemke, Jerry R.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.;Morgan State Univ, Goddard Earth Sci Technol & Res, Baltimore, MD 21239 USA..
    Ziese, Markus
    Deutsch Wetterdienst, Global Precipitat Climatol Ctr, Offenbach, Germany..
    Global Climate: in State of the climate in 20192020In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 101, no 8, p. S17-S127Article in journal (Refereed)
  • 6. Ades, M.
    et al.
    Weyhenmeyer, Gesa A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Ziese, Markus
    State of the Climate in 20182019In: Bulletin of The American Meteorological Society - (BAMS), ISSN 0003-0007, E-ISSN 1520-0477, Vol. 100, no 9, p. Si-S306Article in journal (Other academic)
  • 7.
    Ahlgren, Joakim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    De Brabandere, Heidi
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Reitzel, Kasper
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Waldebäck, Monica
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Sediment Phosphorus Extractants for Phosphorus-31 Nuclear Magnetic Resonance Analysis: A Quantitative Evaluation2007In: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 36, no 3, p. 892-898Article in journal (Refereed)
    Abstract [en]

    The influence of pre-extractant, extractant, and post-extractant on total extracted amounts of P and organic P compound groups measured with 31P nuclear magnetic resonance (31P-NMR) in lacustrine sediment was examined. The main extractants investigated were sodium hydroxide (NaOH) and sodium hydroxide ethylenediaminetetraacetic acid (NaOH-EDTA) with bicarbonate buffered dithionite (BD) or EDTA as pre-extractants. Post extractions were conducted using either NaOH or NaOH-EDTA, depending on the main extractant. Results showed that the most efficient combination of extractants for total P yield was NaOH with EDTA as pre-extractant, yielding almost 50% more than the second best procedure. The P compound groups varying the most between the different extraction procedures were polyphosphates and pyrophosphates. NaOH with BD as pre-extractant was the most efficient combination for these compound groups.

  • 8.
    Ahlgren, Joakim
    et al.
    Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
    Reitzel, Kasper
    Institute of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
    De Brabandere, Heidi
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Release of Organic P Forms from Lake Sediments2011In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 45, no 2, p. 565-572Article in journal (Refereed)
    Abstract [en]

    The effects of different physical and chemical conditions on the decomposition and release of organic and inorganic P compound groups from the sediment of Lake Erken were investigated in a series of laboratory experiments. Conditions investigated were temperature, oxygen level, and the effects of additions of carbon substrate (glucose) and poison (formalin). The effects on the P compound groups were determined by measurements with 31P NMR before and after the experiments, as well as analysis of P in effluent water throughout the experiment. Phosphate analysis of the effluent water showed that oxygen level was the most influential in terms of release rates, with the sediments under anoxic conditions generally releasing more phosphate than the other treatments. 31P NMR showed that the various treatments did influence the P compound group composition of the sediment. In particular, the addition of glucose led to a decrease in orthophosphate and polyphosphate while the addition of formalin led to a decrease in phosphorus lipids, DNAphosphate and polyphosphate. Oxic conditions resulted in an increase in polyphosphates, and anoxic conditions in a decrease in these. Temperature did not seem to affect the composition significantly.

  • 9.
    Ahmed Osman, Omneya
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Beier, Sara
    Leibniz Inst Balt Sea Res, Warnemunde, Germany..
    Grabherr, Manfred
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Interactions of Freshwater Cyanobacteria with Bacterial Antagonists2017In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 83, no 7, article id UNSP e02634Article in journal (Refereed)
    Abstract [en]

    Cyanobacterial and algal mass development, or blooms, have severe effects on freshwater and marine systems around the world. Many of these phototrophs produce a variety of potent toxins, contribute to oxygen depletion, and affect water quality in several ways. Coexisting antagonists, such as cyanolytic bacteria, hold the potential to suppress, or even terminate, such blooms, yet the nature of this interaction is not well studied. We isolated 31 cyanolytic bacteria affiliated with the genera Pseudomonas, Stenotrophomonas, Acinetobacter, and Delftia from three eutrophic freshwater lakes in Sweden and selected four phylogenetically diverse bacterial strains with strong-to-moderate lytic activity. To characterize their functional responses to the presence of cyanobacteria, we performed RNA sequencing (RNA-Seq) experiments on coculture incubations, with an initial predator-prey ratio of 1: 1. Genes involved in central cellular pathways, stress-related heat or cold shock proteins, and antitoxin genes were highly expressed in both heterotrophs and cyanobacteria. Heterotrophs in coculture expressed genes involved in cell motility, signal transduction, and putative lytic activity. L, D-Transpeptidase was the only significantly upregulated lytic gene in Stenotrophomonas rhizophila EK20. Heterotrophs also shifted their central metabolism from the tricarboxylic acid cycle to the glyoxylate shunt. Concurrently, cyanobacteria clearly show contrasting antagonistic interactions with the four tested heterotrophic strains, which is also reflected in the physical attachment to their cells. In conclusion, antagonistic interactions with cyanobacteria were initiated within 24 h, and expression profiles suggest varied responses for the different cyanobacteria and studied cyanolytes. IMPORTANCE Here, we present how gene expression profiles can be used to reveal interactions between bloom-forming freshwater cyanobacteria and antagonistic heterotrophic bacteria. Species-specific responses in both heterotrophs and cyanobacteria were identified. The study contributes to a better understanding of the interspecies cellular interactions underpinning the persistence and collapse of cyanobacterial blooms.

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  • 10. Ali El Hadi Mohamed, Rania
    et al.
    Abdelgadir, Deena M.
    Bashab, Hind M.
    Al-Shuraym, Laila A.
    Sfouq Aleanizy, Fadilah
    Alqahtani, Fulwah Y.
    Ahmed Al-Keridis, Lamya
    Mohamed, Nahla
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Princess Nourah Bint Abdurrahman University.
    First record of West Nile Virus detection inside wild mosquitoes in Khartoum capital of Sudan using PCR2020In: Saudi Journal of Biological Sciences, ISSN 1319-562X, Vol. 27, no 12, p. 3359-3364Article in journal (Refereed)
    Abstract [en]

    This study aimed to explore the presence of West Nile Virus (WNV) inside four species of mosquitoes: Culex univittatus (Theobald), Culex quinquefasciatus (Say) Aedes vittatus (Bigot) and Aedes vexans (Meigen). Adult wild mosquitoes were collected from different sites: Soba West, Hellat Kuku, Shambat, and Khartoum North Central Live Stock Market (KCLM). Surveys were carried out at Khartoum State during two phases: pre to the rainy season and post to the rainy season. Mosquito specimens were identified using classical keys then preserved at −80 °C freezer for two weeks till the virus examination using polymerase chain reaction (PCR) were carried out. WNV has been detected inside the three species of mosquitoes: A. vexans, C. univittatus, and C. quinquefasciatus. The species were collected from Hellat Kuku, (Shambat and Hellat Kuku), and (Shambat and KCLM) respectively. Two species of mosquitoes were positive for the virus: C. quinquefasciatus and C. univittatus. Positive results for the virus during the first phase of the study; males of C. quinquefasciatus and C. univittatus collected during the second phase of the study were also tested for the existence of the virus and they were positive. For our knowledge this study represents first record of WNV inside wild mosquitoes in Sudan. PCR technique provided reliable information because specific primer-probe sets were used for the detection of the virus. Extra studies are required to incriminate these species of mosquitoes as potential vectors of WNV.

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  • 11.
    Allesson, Lina
    et al.
    Univ Oslo, Dept Biosci, Oslo, Norway..
    Koehler, Birgit
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Thrane, Jan-Erik
    Norwegian Inst Water Res, Oslo, Norway..
    Andersen, Tom
    Univ Oslo, Dept Biosci, Oslo, Norway..
    Hessen, Dag O.
    Univ Oslo, Dept Biosci, Oslo, Norway..
    The role of photomineralization for CO2 emissions in boreal lakes along a gradient of dissolved organic matter2021In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, no 1, p. 158-170Article in journal (Refereed)
    Abstract [en]

    Many boreal lakes are experiencing an increase in concentrations of terrestrially derived dissolved organic matter (DOM)-a process commonly labeled "browning." Browning affects microbial and photochemical mineralization of DOM, and causes increased light attenuation and hence reduced photosynthesis. Consequently, browning regulates lake heterotrophy and net CO2-efflux to the atmosphere. Climate and environmental change makes ecological forecasting and global carbon cycle modeling increasingly important. A proper understanding of the magnitude and relative contribution from CO2-generating processes for lakes ranging in dissolve organic carbon (DOC) concentrations is therefore crucial for constraining models and forecasts. Here, we aim to study the relative contribution of photomineralization to total CO(2)production in 70 Scandinavian lakes along an ecosystem gradient of DOC concentration. We combined spectral data from the lakes with regression estimates between optical parameters and wavelength specific photochemical reactivity to estimate rates of photochemical DOC mineralization. Further, we estimated total in-lake CO2-production and efflux from lake chemical and physical data. Photochemical mineralization corresponded on average to 9% +/- 1% of the total CO2-evasion, with the highest contribution in clear lakes. The calculated relative contribution of photochemical mineralization to total in-lake CO2-production was about 3% +/- 0.2% in all lakes. Although lakes differed substantially in color, depth-integrated photomineralization estimates were similar in all lakes, regardless of DOC concentrations. DOC concentrations were positively related to CO2-efflux and total in-lake CO2-production but negatively related to primary production. We conclude that enhanced rates of photochemical mineralization will be a minor contributor to increased heterotrophy under increased browning.

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  • 12. Almeida, Rafael M.
    et al.
    Barros, Nathan
    Cole, Jonathan J.
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Roland, Fabio
    Correspondence: Emissions from Amazonian dams2013In: Nature Climate Change, ISSN 1758-678X, E-ISSN 1758-6798, Vol. 3, no 12, p. 1005-1005Article in journal (Other academic)
  • 13. Almeida, Rafael M.
    et al.
    Barros, Nathan
    Cole, Jonathan J.
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Roland, Fábio
    Emissions from Amazonian dams2013In: Nature Climate Change, ISSN 1758-678X, E-ISSN 1758-6798, Vol. 3, no 12, p. 1005-1005Article in journal (Refereed)
  • 14.
    Almeida, Rafael M.
    et al.
    Univ Fed Juiz de Fora, Inst Ciencias Biol, Dept Biol, Aquat Ecol Lab, Juiz De Fora, Brazil..
    Nobrega, Gabriel N.
    Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, Dept Ciencia Solo, Piracicaba, Brazil..
    Junger, Pedro C.
    Univ Fed Rio de Janeiro, Lab Limnol, Rio De Janeiro, Brazil..
    Figueiredo, Aline V.
    Univ Fed Rio Grande do Norte, Lab Water Resources & Environm Sanitat, BR-59072970 Natal, RN, Brazil..
    Andrade, Anizio S.
    Univ Fed Rio Grande do Norte, Lab Limnol, BR-59072970 Natal, RN, Brazil..
    de Moura, Caroline G. B.
    Univ Fed Rio Grande do Norte, Lab Limnol, BR-59072970 Natal, RN, Brazil..
    Tonetta, Denise
    Univ Fed Santa Catarina, Lab Freshwater Ecol, Florianopolis, SC, Brazil..
    Oliveira, Ernandes S., Jr.
    Radboud Univ Nijmegen, Dept Aquat Ecol & Environm Biol, Inst Water & Wetland Res, NL-6525 ED Nijmegen, Netherlands..
    Araujo, Fabiana
    Univ Fed Rio Grande do Norte, Lab Water Resources & Environm Sanitat, BR-59072970 Natal, RN, Brazil..
    Rust, Felipe
    Univ Fed Juiz de Fora, Inst Ciencias Biol, Dept Biol, Aquat Ecol Lab, Juiz De Fora, Brazil..
    Pineiro-Guerra, Juan M.
    Univ Republica, Dept Ecol Teor & Aplicada, Ctr Univ Reg Este, Montevideo, Uruguay.;Univ Republica, Fac Ciencias, Montevideo, Uruguay..
    Mendonca, Jurandir R., Jr.
    Univ Fed Rio Grande do Norte, Lab Water Resources & Environm Sanitat, BR-59072970 Natal, RN, Brazil..
    Medeiros, Leonardo R.
    Univ Fed Rio Grande do Norte, Lab Limnol, BR-59072970 Natal, RN, Brazil..
    Pinheiro, Lorena
    Univ Fed Estado Rio de Janeiro, Dept Ciencias Nat, Rio De Janeiro, Brazil..
    Miranda, Marcela
    Univ Fed Juiz de Fora, Inst Ciencias Biol, Dept Biol, Aquat Ecol Lab, Juiz De Fora, Brazil..
    Costa, Mariana R. A.
    Univ Fed Rio Grande do Norte, Lab Water Resources & Environm Sanitat, BR-59072970 Natal, RN, Brazil..
    Melo, Michaela L.
    Univ Fed Sao Carlos, Lab Microbial Proc & Biodivers, BR-13560 Sao Carlos, SP, Brazil..
    Nobre, Regina L. G.
    Univ Fed Rio Grande do Norte, Lab Limnol, BR-59072970 Natal, RN, Brazil..
    Benevides, Thiago
    Univ Fed Rio de Janeiro, Lab Limnol, Rio De Janeiro, Brazil..
    Roland, Fabio
    Univ Fed Juiz de Fora, Inst Ciencias Biol, Dept Biol, Aquat Ecol Lab, Juiz De Fora, Brazil..
    de Klein, Jeroen
    Wageningen Univ, Aquat Ecol & Environm Sci, NL-6700 AP Wageningen, Netherlands..
    Barros, Nathan O.
    Univ Fed Juiz de Fora, Inst Ciencias Biol, Dept Biol, Aquat Ecol Lab, Juiz De Fora, Brazil..
    Mendonca, Raquel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Univ Fed Juiz de Fora, Inst Ciencias Biol, Dept Biol, Aquat Ecol Lab, Juiz De Fora, Brazil.
    Becker, Vanessa
    Univ Fed Rio Grande do Norte, Lab Water Resources & Environm Sanitat, BR-59072970 Natal, RN, Brazil..
    Huszar, Veral. M.
    Univ Fed Rio de Janeiro, Museu Nacl, Lab Ficol, Rio De Janeiro, Brazil..
    Kosten, Sarian
    Radboud Univ Nijmegen, Dept Aquat Ecol & Environm Biol, Inst Water & Wetland Res, NL-6525 ED Nijmegen, Netherlands..
    High Primary Production Contrasts with Intense Carbon Emission in a Eutrophic Tropical Reservoir2016In: Frontiers in Microbiology, E-ISSN 1664-302X, Vol. 7, article id 717Article in journal (Refereed)
    Abstract [en]

    Recent studies from temperate lakes indicate that eutrophic systems tend to emit less carbon dioxide (Co-2) and bury more organic carbon (OC) than oligotrophic ones, rendering them CO2 sinks in some cases. However, the scarcity of data from tropical systems is critical for a complete understanding of the interplay between eutrophication and aquatic carbon (C) fluxes in warm waters. We test the hypothesis that a warm eutrophic system is a source of both CO2 and CH4 to the atmosphere, and that atmospheric emissions are larger than the burial of OC in sediments. This hypothesis was based on the following assumptions: (i) OC mineralization rates are high in warm water systems, so that water column CO2 production overrides the high C uptake by primary producers, and (ii) increasing trophic status creates favorable conditions for CH4 production. We measured water-air and sediment-water CO2 fluxes, CH4 diffusion, ebullition and oxidation, net ecosystem production (NEP) and sediment OC burial during the dry season in a eutrophic reservoir in the semiarid northeastern Brazil. The reservoir was stratified during daytime and mixed during nighttime. In spite of the high rates of primary production (4858 +/- 934 mg C m(-2) d(-1)), net heterotrophy was prevalent due to high ecosystem respiration (5209 +/- 992 mg C m(-2) d(-1)). Consequently, the reservoir was a source of atmospheric CO2 (518 +/- 182 mg C m(-2) d(-1)). In addition, the reservoir was a source of ebullitive (17 +/- 10 mg C m(-2) d(-1)) and diffusive CH4 (11 +/- 6 mg C m(-2) d(-1)). OC sedimentation was high (1162 mg C m(-2) d(-1)), but our results suggest that the majority of it is mineralized to CO2 (722 +/- 182 mg C m(-2) d(-1)) rather than buried as OC (440 mg C m(-2) d(-1)). Although temporally resolved data would render our findings more conclusive, our results suggest that despite being a primary production and OC burial hotspot, the tropical eutrophic system studied here was a stronger CO2 and CH4 source than a C sink, mainly because of high rates of OC mineralization in the water column and sediments.

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  • 15.
    Almeida, Rafael M.
    et al.
    Cornell University, USA.
    Paranaíba, José R.
    Federal University of Juiz de Fora, Brazil.
    Barbosa, Ícaro
    Federal University of Juiz de Fora, Brazil.
    Sobek, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Kosten, Sarian
    University Nijmegen, The Netherlands.
    Linkhorst, Annika
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Mendonça, Raquel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Federal University of Juiz de Fora, Brazil.
    Quadra, Gabrielle
    Federal University of Juiz de Fora, Brazil.
    Roland, Fábio
    Federal University of Juiz de Fora, Brazil.
    Barros, Nathan
    Federal University of Juiz de Fora, Brazil.
    Carbon dioxide emission from drawdown areas of a Brazilian reservoir is linked to surrounding land cover2019In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 81, article id 68Article in journal (Refereed)
    Abstract [en]

    Reservoir sediments exposed to air due to water level fluctuations are strong sources of atmospheric carbon dioxide (CO2). The spatial variability of CO2 fluxes from these drawdown areas are still poorly understood. In a reservoir in southeastern Brazil, we investigated whether CO2 emissions from drawdown areas vary as a function of neighboring land cover types and assessed the magnitude of CO2 fluxes from drawdown areas in relation to nearby water surface. Exposed sediments near forestland (average = 2733 mg C m−2 day−1) emitted more CO2 than exposed sediments near grassland (average = 1261 mg C m−2 day−1), congruent with a difference in organic matter content between areas adjacent to forestland (average = 12.2%) and grassland (average = 10.9%). Moisture also had a significant effect on CO2 emission, with dry exposed sediments (average water content: 13.7%) emitting on average 2.5 times more CO2 than wet exposed sediments (average water content: 23.5%). We carried out a systematic comparison with data from the literature, which indicates that CO2 efflux from drawdown areas globally is about an order of magnitude higher than CO2 efflux from adjacent water surfaces, and within the range of CO2 efflux from terrestrial soils. Our findings suggest that emissions from exposed sediments may vary substantially in space, possibly related to organic matter supply from uphill vegetation, and that drawdown areas play a disproportionately important role in total reservoir CO2 emissions with respect to the area they cover.

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  • 16. Almeida, Rafael M.
    et al.
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Huszar, Vera L. M.
    Sobek, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Mendonca, Raquel
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Barros, Nathan
    Boemer, Gina
    Arantes, Joao Durval, Jr.
    Roland, Fabio
    Phosphorus transport by the largest Amazon tributary (Madeira River, Brazil) and its sensitivity to precipitation and damming2015In: Inland Waters, ISSN 2044-2041, E-ISSN 2044-205X, Vol. 5, no 3, p. 275-282Article in journal (Refereed)
    Abstract [en]

    Originating in the Bolivian and Peruvian Andes, the Madeira River is the largest tributary of the Amazon River in terms of discharge. Andean rivers transport large quantities of nutrient-rich suspended sediments and are the main source of phosphorus (P) to the Amazon basin. Here, we show the seasonal variability in concentrations and loads of different P forms (total, particulate, dissolved, and soluble reactive P) in the Madeira River through 8 field campaigns between 2009 and 2011. At our sampling reach in Porto Velho, Brazil, the Madeira River transports similar to 177-247 Gg yr(-1) of P, mostly linked to particles (similar to 85%). Concentrations and loads of all P forms have a maximum at rising waters and a minimum at low waters. Total P concentrations were substantially higher at a given discharge at rising water than at a similar discharge at falling water. The peak of P concentrations matched the peak of rainfall in the upper basin, suggesting an influence of precipitation-driven erosion. Projected precipitation increase in the eastern slopes of the Andes could enhance sediment yield and hence the P transport in the Madeira River. Because most of the P is particulate, however, we hypothesize that the planned proliferation of hydropower dams in the Madeira basin has the potential to reduce P loads substantially, possibly counteracting any precipitation-related increases. In the long term, this could be detrimental to highly productive downstream floodplain forests that are seasonally fertilized with P-rich deposits.

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  • 17.
    Alneberg, Johannes
    et al.
    KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Dept Gene Technol, Sci Life Lab, Stockholm, Sweden.
    Karlsson, Christofer M. G.
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst, EEMiS, Kalmar, Sweden.
    Divne, Anna-Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bergin, Claudia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Homa, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Lindh, Markus V.
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst, EEMiS, Kalmar, Sweden;Lund Univ, Dept Biol, Lund, Sweden.
    Hugerth, Luisa W.
    KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Dept Gene Technol, Sci Life Lab, Stockholm, Sweden;Karolinska Inst, Ctr Translat Microbiome Res, Dept Mol Tumour & Cell Biol, Sci Life Lab, Solna, Sweden.
    Ettema, Thijs J. G.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular Evolution. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Andersson, Anders F.
    KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Dept Gene Technol, Sci Life Lab, Stockholm, Sweden.
    Pinhassi, Jarone
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst, EEMiS, Kalmar, Sweden.
    Genomes from uncultivated prokaryotes: a comparison of metagenome-assembled and single-amplified genomes2018In: Microbiome, E-ISSN 2049-2618, Vol. 6, article id 173Article in journal (Refereed)
    Abstract [en]

    Background: Prokaryotes dominate the biosphere and regulate biogeochemical processes essential to all life. Yet, our knowledge about their biology is for the most part limited to the minority that has been successfully cultured. Molecular techniques now allow for obtaining genome sequences of uncultivated prokaryotic taxa, facilitating in-depth analyses that may ultimately improve our understanding of these key organisms.

    Results: We compared results from two culture-independent strategies for recovering bacterial genomes: single-amplified genomes and metagenome-assembled genomes. Single-amplified genomes were obtained from samples collected at an offshore station in the Baltic Sea Proper and compared to previously obtained metagenome-assembled genomes from a time series at the same station. Among 16 single-amplified genomes analyzed, seven were found to match metagenome-assembled genomes, affiliated with a diverse set of taxa. Notably, genome pairs between the two approaches were nearly identical (average 99.51% sequence identity; range 98.77-99.84%) across overlapping regions (30-80% of each genome). Within matching pairs, the single-amplified genomes were consistently smaller and less complete, whereas the genetic functional profiles were maintained. For the metagenome-assembled genomes, only on average 3.6% of the bases were estimated to be missing from the genomes due to wrongly binned contigs.

    Conclusions: The strong agreement between the single-amplified and metagenome-assembled genomes emphasizes that both methods generate accurate genome information from uncultivated bacteria. Importantly, this implies that the research questions and the available resources are allowed to determine the selection of genomics approach for microbiome studies.

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  • 18.
    Alonso-Saez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Unanue, Marian
    Latatu, Ainhoa
    Azua, Inigo
    Ayo, Begona
    Artolozaga, Itxaso
    Iriberri, Juan
    Changes in marine prokaryotic community induced by varying types of dissolved organic matter and subsequent grazing pressure2009In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 31, no 11, p. 1373-1383Article in journal (Refereed)
    Abstract [en]

    We analysed changes in the abundance, biomass, activity and composition of coastal marine prokaryotic communities after the addition of organic substrates, such as glucose, leucine and yeast extract, and the effect of grazing pressure exerted by nanoflagellates. The addition of a carbon source (i.e. glucose) promoted the growth of Gammaproteobacteria, while a combined source of C and N (i.e. leucine) favoured the development of Alphaproteobacteria. The addition of yeast extract, a complex substrate rich in N and growth factors, promoted the proliferation of Alphaproteobacteria and Gammaproteobacteria. Grazing pressure exerted by nanoflagellates produced marked differences on the size structure of the prokaryotic biomass. A pronounced tendency to filamentation and aggregation was observed in the glucose treatment, while in the case of yeast extract, small and mainly freely dispersed prokaryotes were maintained throughout the incubations. Thus, the final community in the yeast extract treatment showed a high percentage of edible biomass, while an important fraction of potentially grazing-resistant prokaryotes (more than 50% of total prokaryotic biomass) was detected in the microcosms enriched with glucose. These results suggest a marked effect of DOM sources on the development of grazing-resistant prokaryotes.

  • 19.
    Alonso-Saez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Vazquez-Dominguez, Evaristo
    Cardelus, Clara
    Pinhassi, Jarone
    Sala, M. Montserrat
    Lekunberri, Itziar
    Balague, Vanessa
    Vila-Costa, Maria
    Unrein, Fernando
    Massana, Ramon
    Simo, Rafel
    Gasol, Josep M.
    Factors controlling the year-round variability in carbon flux through bacteria in a coastal marine system2008In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 11, no 3, p. 397-409Article in journal (Refereed)
    Abstract [en]

    Data from several years of monthly samplings are combined with a 1-year detailed study of carbon flux through bacteria at a NW Mediterranean coastal site to delineate the bacterial role in carbon use and to assess whether environmental factors or bacterial assemblage composition affected the in situ rates of bacterial carbon processing. Leucine (Leu) uptake rates [as an estimate of bacterial heterotrophic production (BHP)] showed high interannual variability but, on average, lower values were found in winter (around 50 pM Leu(-1) h(-1)) as compared to summer (around 150 pM Leu(-1) h(-1)). Leu-to-carbon conversion factors ranged from 0.9 to 3.6 kgC mol Leu(-1), with generally higher values in winter. Leu uptake was only weakly correlated to temperature, and over a full-year cycle (in 2003), Leu uptake peaked concomitantly with winter chlorophyll a (Chl a) maxima, and in periods of high ectoenzyme activities in spring and summer. This suggests that both low molecular weight dissolved organic matter (DOM) released by phytoplankton, and high molecular weight DOM in periods of low Chl a, can enhance BHP. Bacterial respiration (BR, range 7-48 mu g C l(-1) d(-1)) was not correlated to BHP or temperature, but was significantly correlated to DOC concentration. Total bacterial carbon demand (BHP plus BR) was only met by dissolved organic carbon produced by phytoplankton during the winter period. We measured bacterial growth efficiencies by the short-term and the long-term methods and they ranged from 3 to 42%, increasing during the phytoplankton blooms in winter (during the Chl a peaks), and in spring. Changes in bacterioplankton assemblage structure (as depicted by denaturing gradient gel electrophoresis fingerprinting) were not coupled to changes in ecosystem functioning, at least in bacterial carbon use.

  • 20.
    Alonso-Saez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Zeder, Michael
    Harding, Tommy
    Pernthaler, Jakob
    Lovejoy, Connie
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Pedros-Alio, Carlos
    Winter bloom of a rare betaproteobacteriurn in the Arctic Ocean2014In: Frontiers in Microbiology, E-ISSN 1664-302X, Vol. 5, p. 425-Article in journal (Refereed)
    Abstract [en]

    Extremely low abundance microorganisms (members of the "rare biosphere") are believed to include dormant taxa, which can sporadically become abundant following environmental triggers. Yet, microbial transitions from rare to abundant have seldom been captured in situ, and it is uncertain how widespread these transitions are. A bloom of a single ribotype (>= 99% similarity in the 16S ribosomal RNA gene) of a widespread betaproteobacterium (Janthinobacterium sp.) occurred over 2 weeks in Arctic marine waters. The Janthinobactenum population was not detected microscopically in situ in January and early February, but suddenly appeared in the water column thereafter, eventually accounting for up to 20% of bacterial cells in mid February. During the bloom, this bacterium was detected at open water sites up to 50 km apart, being abundant down to more than 300 m. This event is one of the largest monospecific bacterial blooms reported in polar oceans. It is also remarkable because Betaproteobacteria are typically found only in low abundance in marine environments. In particular, Janthinobacterium were known from non-marine habitats and had previously been detected only in the rare biosphere of seawater samples, including the polar oceans. The Arctic Janthinobacterium formed mucilagenous monolayer aggregates after short (ca. 8 h) incubations, suggesting that biofilm formation may play a role in maintaining rare bacteria in pelagic marine environments. The spontaneous mass occurrence of this opportunistic rare taxon in polar waters during the energy-limited season extends current knowledge of how and when microbial transitions between rare and abundant occur in the ocean.

  • 21.
    Alonso-Sáez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Andersson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Heinrich, Friederike
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    High archaeal diversity in Antarctic circumpolar deep waters2011In: Environmental Microbiology Reports, E-ISSN 1758-2229, Vol. 3, no 6, p. 689-697Article in journal (Refereed)
    Abstract [en]

    Archaea are abundant in polar oceans but important ecological aspects of this group remain enigmatic, such as patterns of diversity and biogeography. Here, we provide the first high-throughput sequencing population study of Antarctic archaea based on 198 bp fragments of the 16S rRNA gene, targeting different water masses across the Amundsen and Ross Seas. Our results suggest that archaeal community composition is strongly shaped by hydrography and significantly influenced by environmental parameters. Archaeal communities from cold continental shelf waters (SW) of the Ross Sea were similar over depth with a single thaumarchaeal phylotype dominating Antarctic surface waters (AASW) and deeper SW (contributing up to 80% of reads). However, this phylotype contributed less than 8% of reads in circumpolar deep waters (CDW). A related thaumarchaeon (98% identity) was almost absent in AASW, but contributed up to 30% of reads in CDW, suggesting ecological differentiation of closely related phylotypes. Significantly higher archaeal richness and evenness were observed in CDW, with Shannon indices (c. 2.5) twice as high as for AASW, and high contributions of Group II Euryarchaeota. Based on these results, we suggest that CDW is a hotspot of archaeal diversity and may play an important role in the dispersal of archaeal phylotypes to other oceanic water masses.

  • 22.
    Alonso-Sáez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Waller, A. S.
    Mende, D. R.
    Bakker, K.
    Farnelid, H.
    Yager, P. L.
    Lovejoy, C.
    Tremblay, J. -E
    Potvin, M.
    Heinrich, Friederike
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Estrada, M.
    Riemann, L.
    Bork, P.
    Pedrós-Alió, C.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Role for urea in nitrification by polar marine Archaea2012In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 109, no 44, p. 17989-17994Article in journal (Refereed)
    Abstract [en]

    Despite the high abundance of Archaea in the global ocean, their metabolism and biogeochemical roles remain largely unresolved. We investigated the population dynamics and metabolic activity of Thaumarchaeota in polar environments, where these microorganisms are particularly abundant and exhibit seasonal growth. Thaumarchaeota were more abundant in deep Arctic and Antarctic waters and grew throughout the winter at surface and deeper Arctic halocline waters. However, in situ single-cell activity measurements revealed a low activity of this group in the uptake of both leucine and bicarbonate (<5% Thaumarchaeota cells active), which is inconsistent with known heterotrophic and autotrophic thaumarchaeal lifestyles. These results suggested the existence of alternative sources of carbon and energy. Our analysis of an environmental metagenome from the Arctic winter revealed that Thaumarchaeota had pathways for ammonia oxidation and, unexpectedly, an abundance of genes involved in urea transport and degradation. Quantitative PCR analysis confirmed that most polar Thaumarchaeota had the potential to oxidize ammonia, and a large fraction of them had urease genes, enabling the use of urea to fuel nitrification. Thaumarchaeota from Arctic deep waters had a higher abundance of urease genes than those near the surface suggesting genetic differences between closely related archaeal populations. In situ measurements of urea uptake and concentration in Arctic waters showed that small-sized prokaryotes incorporated the carbon from urea, and the availability of urea was often higher than that of ammonium. Therefore, the degradation of urea may be a relevant pathway for Thaumarchaeota and other microorganisms exposed to the low-energy conditions of dark polar waters.

  • 23.
    Anandhi, Aavudai
    et al.
    Florida A&M Univ, Coll Agr & Food Sci, Biol Syst Engn, Tallahassee, FL 32307 USA;Florida A&M Univ, Coll Agr & Food Sci, Ctr Water Resources, Tallahassee, FL 32307 USA.
    Pierson, Don
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Frei, Allan
    CUNY, Hunter Coll, Dept Geog, New York, NY 10065 USA;CUNY, CUNY Inst Sustainable Cities, New York, NY 10065 USA.
    Evaluation of Climate Model Performance for Water Supply Studies: Case Study for New York City2019In: Journal of water resources planning and management, ISSN 0733-9496, E-ISSN 1943-5452, Vol. 145, no 8, article id 06019006Article in journal (Refereed)
    Abstract [en]

    Evaluating the suitability of data from global climate models (GCMs) for use as input in water supply models is an important step in the larger task of evaluating the effects of climate change on water resources management such as that of water supply operations. The purpose of this paper is to present the process by which GCMs were evaluated and incorporated into the New York City (NYC) water supply's planning activities and to provide conclusions regarding the overall effectiveness of the ranking procedure used in the evaluation. A suite of GCMs participating in Phase 3 of the Coupled Model Intercomparison Project (CMIP3) were evaluated for use in climate change projections in the watersheds of the NYC water supply that provide 90% of the water consumed by NYC. GCM data were aggregated using the seven land-grid points surrounding NYC watersheds, and these data with a daily timestep were evaluated seasonally using probability-based skill scores for various combinations of five meteorological variables (precipitation, average, maximum and minimum temperatures, and wind speed). These are the key variables for the NYC water supply because they affect the timing and magnitude of water, energy, sediment, and nutrient fluxes into the reservoirs as well as in simulating watershed hydrology and reservoir hydrodynamics. We attempted to choose a subset of GCMs based on the average of several skill metrics that compared baseline (20C3M) GCM results to observations. Skill metrics for the study indicate that the skill in simulating the frequency distributions of measured data is highest for temperature and lowest for wind. However, our attempts to identify the best model or subgroup of models were not successful because we found that no single model performs best when considering all of the variables and seasons.

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  • 24.
    Andersson, Anders F.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Pelve, Erik A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Lindeberg, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Lundgren, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Microbiology.
    Nilsson, Peter
    Bernander, Rolf
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Molecular Evolution.
    Replication-biased genome organisation in the crenarchaeon Sulfolobus2010In: BMC Genomics, E-ISSN 1471-2164, Vol. 11, p. 454-Article in journal (Refereed)
    Abstract [en]

    Background: Species of the crenarchaeon Sulfolobus harbour three replication origins in their single circular chromosome that are synchronously initiated during replication. Results: We demonstrate that global gene expression in two Sulfolobus species is highly biased, such that early replicating genome regions are more highly expressed at all three origins. The bias by far exceeds what would be anticipated by gene dosage effects alone. In addition, early replicating regions are denser in archaeal core genes (enriched in essential functions), display lower intergenic distances, and are devoid of mobile genetic elements. Conclusion: The strong replication-biased structuring of the Sulfolobus chromosome implies that the multiple replication origins serve purposes other than simply shortening the time required for replication. The higher-level chromosomal organisation could be of importance for minimizing the impact of DNA damage, and may also be linked to transcriptional regulation.

  • 25. Andersson, Eva
    et al.
    Sobek, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Comparison of a mass balance and an ecosystem model approach when evaluating the carbon cycling in a lake ecosystem2006In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 35, no 8, p. 476-483Article in journal (Refereed)
  • 26.
    Andersson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Abundance data adaptation experiment2017Data set
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  • 27.
    Andersson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Bacterial abundance data from sterilization experiment2017Data set
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  • 28.
    Andersson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Extent and limitations of functional redundancy among bacterial communities towards dissolved organic matter2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    One of the key processes in the carbon cycle on our planet is the degradation of dissolved organic matter (DOM) in aquatic environments. The use of organic matter by bacteria links energy from DOM to higher trophic levels of the ecosystem when bacteria are consumed by other organisms. This is referred to as the microbial loop. In this thesis I examined if the communities were functionally redundant in their ability to utilize organic matter, or if variation in bacterial composition and richness is of importance. To test this overarching question several experiments were conducted that include methods such as illumina sequencing of the 16S rRNA gene for taxonomic identification of bacterial communities, flow cytometry to follow the growth of communities and spectroscopic measurement to describe the composition of the organic matter pool. Initially we demonstrated how to optimally sterilize organic matter for experimental studies in order to preserve its natural complexity. In further experiments we found that bacterial communities are redundant in their utilization of organic matter and can maintain optimal performance towards a range of organic matter pools. Related to this we found that pre-adaptation to organic matter played a small role as communities performed equally well regardless of their environmental history. We saw a small effect of richness and composition of bacterial communities on the efficiency of organic matter use, but conclude that this is of minor importance relative to abiotic factors. Still, we also show that organic matter can put strong selection pressure on bacterial communities with regards to richness and composition. Additionally we found that the supply rate of a carbon compound greatly influenced the energy utilization of the compound, i.e. a higher growth rate can be maintained if substrate is delivered in pulses relative to a continuous flow. Finally we conclude that the variation in bacterial communities is unlikely to have a major influence on carbon cycling in boreal lakes, but to enable a finer understanding, the genetics underlying the carbon utilization needs to be further explored. 

    List of papers
    1. Effects of sterilization on dissolved organic carbon (DOC) composition and bacterial utilization of DOC from lakes
    Open this publication in new window or tab >>Effects of sterilization on dissolved organic carbon (DOC) composition and bacterial utilization of DOC from lakes
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    2018 (English)In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 82, no 2, p. 199-208Article in journal (Refereed) Published
    Abstract [en]

    Sterilization of dissolved organic carbon (DOC) is an essential step in research on interactions between DOC and organisms, for example where the effect of different microbial communities on DOC is studied or vice versa. However, few studies have gone beyond acknowledging that sterilization of DOC influences its characteristics. Here, we aimed to provide further knowledge that enables scientists to better tailor their sterilization methods to their research question. To meet this aim, we conducted a sterilization experiment with DOC from 4 boreal lakes treated with 4 sterilization methods, i.e. 2 filtrations (0.2 µm, 0.1 µm) and 2 autoclaving approaches (single and double autoclaving with a single pH adjustment). Quantity and spectroscopic properties of DOC, before and after sterilization, were studied, and DOC was further tested as a substrate for bacterial growth. We found that the filtration methods better preserved the different DOC measures. In contrast, autoclaving caused major inconsistent shifts in both qualitative and quantitative measures of DOC, as well as an increase of the maximum abundance of bacteria in growth experiments. Nonetheless, there remains a trade-off between retaining the quality of DOC and achieving sterile conditions. Therefore, the sterilization method of choice should be guided by the scientific question at hand.

    Keywords
    sterilization, autoclave, filtration, dissolved organic carbon, excitation emission matrices, parallel factor analysis
    National Category
    Biological Sciences
    Research subject
    Microbiology
    Identifiers
    urn:nbn:se:uu:diva-331676 (URN)10.3354/ame01890 (DOI)000454321300006 ()
    Note

    Title in Thesis list of papers: Effects of sterilization on composition and bacterial utilization of dissolved organic carbon

    Available from: 2017-10-16 Created: 2017-10-16 Last updated: 2021-03-25Bibliographically approved
    2. Influence of pulsed and continuous substrate inputs on freshwater bacterial community composition and functioning in bioreactors
    Open this publication in new window or tab >>Influence of pulsed and continuous substrate inputs on freshwater bacterial community composition and functioning in bioreactors
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    2017 (English)In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 19, no 12, p. 5078-5087Article in journal (Refereed) Published
    Abstract [en]

    Aquatic environments are typically not homogenous, but characterized by changing substrate concentration gradients and nutrient patches. This heterogeneity in substrate availability creates a multitude of niches allowing bacteria with different substrate utilization strategies to hypothetically coexist even when competing for the same substrate. To study the impact of heterogeneous distribution of organic substrates on bacterioplankton, bioreactors with freshwater bacterial communities were fed artificial freshwater medium with acetate supplied either continuously or in pulses. After a month-long incubation, bacterial biomass and community-level substrate uptake rates were twice as high in the pulsed treatment compared to the continuously fed reactors even if the same total amount of acetate was supplied to both treatments. The composition of the bacterial communities emerging in the two treatments differed significantly with specific taxa overrepresented in the respective treatments. The higher estimated growth yield in cultures that received pulsed substrate inputs, imply that such conditions enable bacteria to use resources more efficiently for biomass production. This finding agrees with established concepts of basal maintenance energy requirements and high energetic costs to assimilate substrates at low concentration. Our results further imply that degradation of organic matter is influenced by temporal and spatial heterogeneity in substrate availability. 

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-275178 (URN)10.1111/1462-2920.13979 (DOI)000418352800021 ()29124844 (PubMedID)
    Funder
    Swedish Research Council, 2012-3892
    Available from: 2016-02-01 Created: 2016-02-01 Last updated: 2022-01-29Bibliographically approved
    3. Response and effect interactions between bacterial communities and organic matter
    Open this publication in new window or tab >>Response and effect interactions between bacterial communities and organic matter
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    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The interaction between bacteria and dissolved organic matter (DOM) is crucial for the global carbon cycling. Despite decades of research there are, however, few consistent patterns regarding the relationship between bacterial diversity and community composition and DOM. Here we hypothesized that one reason for such inconsistences among studies is that bacterial communities can adapt to a DOM source over time, whereby a change in the functioning of a community can be, at least partly, decoupled from its composition and diversity. To test this idea we performed a reciprocal transplant experiment with medium (i.e. DOM source) and bacterial communities from two boreal lakes. In this experiment the two communities were allowed to adapt to their indigenous and their foreign source of DOM over 42 days. Bacterial community composition (BCC) was measured throughout the experiment. In addition we measured the capacity of the communities to use DOM, in repeated short (5 days) separated bioassays. The results show a response of bacterial community composition to the DOM sources which was influenced by the origin of the community. In contrast, we could not show an effect of BCC on DOM-processing and functional performance. Indeed, communities of different origin processed the two DOM sources equally well even at the beginning of the experiment. This work demonstrates that the DOM pool can be a strong selective force for BCC but not vice versa. 

    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-331696 (URN)
    Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2017-10-23
    4. The relative importance of richness and BCC for DOC degradation
    Open this publication in new window or tab >>The relative importance of richness and BCC for DOC degradation
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The importance of biodiversity has been of primary interest for ecologist the last 20 years, giving rise to biodiversity ecosystem function (BEF) studies. Within the traditional field of ecology reoccurring patterns have emerged but within microbial ecology the importance of species richness for functioning is still poorly understood with few consistent patterns. In this study we examined the effect of species richness for dissolved organic matter degradation in lakes. This was examined within a smaller span of species richness compared to what is typically in microbial BEF experiments. Bacterial communities of reduced species richness were exposed to a range of DOC environments to test if reduced richness changed the functioning of communities and if the effect was similar among DOC environments. This was conducted in a full factorial design of 3 levels, with 6 dilutions, 5 media and 3 inocula resulting in 90 treatments. Overall, richness and community composition appeared to have effects on DOC degradation, but these effects were minor compared to the variation caused by the different DOC sources. Further, the importance of species richness varied among media and, thus, the chemical complexity of the environment influenced the biodiversity-ecosystem functioning relationship. 

    National Category
    Biological Sciences
    Research subject
    Microbiology
    Identifiers
    urn:nbn:se:uu:diva-331693 (URN)
    Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2017-10-23
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  • 29.
    Andersson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Spectroscopic data / carbon quality measurements1987Data set
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    dataset
  • 30.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Berga, Mercè
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Lindström, Eva S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    The spatial structure of bacterial communities is influenced by historical environmental conditions2014In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 95, no 5, p. 1134-1140Article in journal (Refereed)
    Abstract [en]

    The spatial structure of ecological communities, including that of bacteria, is often influenced by species sorting by contemporary environmental conditions. Moreover, historical processes, i.e., ecological and evolutionary events that have occurred at some point in the past, such as dispersal limitation, drift, priority effects, or selection by past environmental conditions, can be important, but are generally investigated much less. Here, we conducted a field study using 16 rock pools, where we specifically compared the importance of past vs. contemporary environmental conditions for bacterial community structure by correlating present differences in bacterial community composition among pools to environmental conditions measured on the same day, as well as to those measured 2, 4, 6, and 8 d earlier. The results prove that selection by past environmental conditions exists, since we were able to show that bacterial communities are, to a greater extent, an imprint of past compared to contemporary environmental conditions. We suggest that this is the result of a combination of different mechanisms, including priority effects that cause rapid adaptation to new environmental conditions of taxa that have been initially selected by past environmental conditions, and slower rates of turnover in community composition compared to environmental conditions.

  • 31.
    Andersson, Martin G. I.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Catalán, Núria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. ICRA, Catalan Institute of Water Research, Girona, Spain.
    Rahman, Zeeshanur
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Applied Microbiology and Biotechnology Laboratory, Department of Botany, University of Delhi.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Lindström, Eva S.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Effects of sterilization on dissolved organic carbon (DOC) composition and bacterial utilization of DOC from lakes2018In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 82, no 2, p. 199-208Article in journal (Refereed)
    Abstract [en]

    Sterilization of dissolved organic carbon (DOC) is an essential step in research on interactions between DOC and organisms, for example where the effect of different microbial communities on DOC is studied or vice versa. However, few studies have gone beyond acknowledging that sterilization of DOC influences its characteristics. Here, we aimed to provide further knowledge that enables scientists to better tailor their sterilization methods to their research question. To meet this aim, we conducted a sterilization experiment with DOC from 4 boreal lakes treated with 4 sterilization methods, i.e. 2 filtrations (0.2 µm, 0.1 µm) and 2 autoclaving approaches (single and double autoclaving with a single pH adjustment). Quantity and spectroscopic properties of DOC, before and after sterilization, were studied, and DOC was further tested as a substrate for bacterial growth. We found that the filtration methods better preserved the different DOC measures. In contrast, autoclaving caused major inconsistent shifts in both qualitative and quantitative measures of DOC, as well as an increase of the maximum abundance of bacteria in growth experiments. Nonetheless, there remains a trade-off between retaining the quality of DOC and achieving sterile conditions. Therefore, the sterilization method of choice should be guided by the scientific question at hand.

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  • 32.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Rahman, Zeeshanur
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Applied Microbiology and Biotechnology Laboratory, Department of Botany, University of Delhi.
    Catalán, Núria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Catalan Institute for Water Research (ICRA).
    Lindström, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    The relative importance of richness and BCC for DOC degradationManuscript (preprint) (Other academic)
    Abstract [en]

    The importance of biodiversity has been of primary interest for ecologist the last 20 years, giving rise to biodiversity ecosystem function (BEF) studies. Within the traditional field of ecology reoccurring patterns have emerged but within microbial ecology the importance of species richness for functioning is still poorly understood with few consistent patterns. In this study we examined the effect of species richness for dissolved organic matter degradation in lakes. This was examined within a smaller span of species richness compared to what is typically in microbial BEF experiments. Bacterial communities of reduced species richness were exposed to a range of DOC environments to test if reduced richness changed the functioning of communities and if the effect was similar among DOC environments. This was conducted in a full factorial design of 3 levels, with 6 dilutions, 5 media and 3 inocula resulting in 90 treatments. Overall, richness and community composition appeared to have effects on DOC degradation, but these effects were minor compared to the variation caused by the different DOC sources. Further, the importance of species richness varied among media and, thus, the chemical complexity of the environment influenced the biodiversity-ecosystem functioning relationship. 

  • 33.
    Andersson, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Rahman, Zeeshanur
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Applied Microbiology and Biotechnology Laboratory, Department of Botany, University of Delhi.
    Catalán, Núria
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Catalan Institute for Water Research (ICRA).
    Tranvik, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Lindström, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Response and effect interactions between bacterial communities and organic matterManuscript (preprint) (Other academic)
    Abstract [en]

    The interaction between bacteria and dissolved organic matter (DOM) is crucial for the global carbon cycling. Despite decades of research there are, however, few consistent patterns regarding the relationship between bacterial diversity and community composition and DOM. Here we hypothesized that one reason for such inconsistences among studies is that bacterial communities can adapt to a DOM source over time, whereby a change in the functioning of a community can be, at least partly, decoupled from its composition and diversity. To test this idea we performed a reciprocal transplant experiment with medium (i.e. DOM source) and bacterial communities from two boreal lakes. In this experiment the two communities were allowed to adapt to their indigenous and their foreign source of DOM over 42 days. Bacterial community composition (BCC) was measured throughout the experiment. In addition we measured the capacity of the communities to use DOM, in repeated short (5 days) separated bioassays. The results show a response of bacterial community composition to the DOM sources which was influenced by the origin of the community. In contrast, we could not show an effect of BCC on DOM-processing and functional performance. Indeed, communities of different origin processed the two DOM sources equally well even at the beginning of the experiment. This work demonstrates that the DOM pool can be a strong selective force for BCC but not vice versa. 

  • 34.
    Andersson, Matilda L.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Fish population responses to climate change: Causes and consequences2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lake environments are heterogeneous, and animals show a variety of adaptations to deal with this heterogeneity. Fish often show intraspecific variation in diet, metabolism, and behavior, corresponding to their habitat use. Studies on climate change often ignore this heterogeneity and its importance in determining population-level responses to climate change. 

    This thesis can be broken into two interacting pieces. First, my goal was to assess how water color and temperature changes impact the size, number, and distribution of a common predator, Eurasian perch (Perca fluviatilis), in Swedish lakes. Second, I aimed to examine whether metabolism and resource use differed between lake habitats, corresponding with documented patterns of polymorphism and whether diet differences were maintained along a thermal and water color gradient. By combining the information gleaned from these studies, the overarching goal of my thesis is to better understand how climate change will impact fish populations and how intraspecific variance in these responses will impact ecosystem functioning. 

    I found that warming and browning will likely decrease fish biomass but via different mechanisms. Warming reduces average fish size through its impact on metabolism and energy requirements. Browning decreases fish abundance likely due to its negative effects on resource abundance, increasing mortality, and decreasing reproductive effort. Though warming decreases biomass at the lake level, pelagic perch abundance increases. I found that these pelagic perch have higher metabolic rates and, especially in darker lakes, rely heavily on pelagic resources. As more fish shift into the pelagic habitat, this will increase top-down pressure on pelagic resources and decrease energy transfer from littoral to pelagic habitats altering energy flow within lakes. 

    Variation in metabolic phenotype across habitats, combined with the positive scaling of metabolic rates with temperature, will likely determine which fish can persist under climate change scenarios. Studies that measure this variation rely heavily on respirometry to measure fish metabolism. I found that current respirometry methods underestimate maximum metabolic rate and suggest an updated method to improve the accuracy of future studies. 

    Overall, I conclude that habitats should be examined separately to better understand population-level responses to climate change. Perch caught in different habitats have different energy requirements and respond differently to warming and browning. These differences will affect the distribution of top-down pressure and habitat coupling within lake ecosystems, with implications for broader ecosystem functioning in the future.