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  • 1. Abrahamsson, K
    et al.
    Ekdahl, A
    Collén, J
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för fysiologisk botanik.
    Pedersen, M
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för fysiologisk botanik.
    Marine algae - a source of trichloroethylene and perchloroethylene1995Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 40, nr 7, s. 1321-1326s. 1321-1326Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Our results show the natural production of two olefins, trichloroethylene and perchloroethylene, by various marine macroalgae and a microalga. We found significant difference in the ability of the algae to produce these compounds. The production rates for trichloroethylenevaried between 0.022 and 3,400 ng g-l fresh wt (FW)h-l and were generally higher than those for perchloroethylene(0.0026-8.2 ng g-l FW h-l). The two subtropicalalgae, Asparagopsis taxiformis and Falkenbergia hillebrandii,showed the highest formation rates. One axenicmarine red microalga, Porphyridium purpureum, was alsotested and it could also produce trichloroethylene and perchloroethylene.The measured rates suggest that the emissionof trichloroethylene and perchloroethylene from theoceans to the atmosphere may be of such a magnitude thatit cannot be neglected in the global atmospheric chlorinebudget.

  • 2. Adrian, Rita
    et al.
    O`Reilly, Catherine M.
    Zagarese, Horacio
    Baines, Stephen B.
    Hessen, Dag O.
    Keller, Wendel
    Livingstone, David M.
    Sommaruga, Ruben
    Straile, Dietmar
    Van Donk, Ellen
    Weyhenmeyer, Gesa A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Winder, Monika
    Lakes as sentinels of climate change2009Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 54, nr 6(2), s. 2283-2297Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    While there is a general sense that lakes can act as sentinels of climate change, their efficacy has not been thoroughly analyzed. We identified the key response variables within a lake that act as indicators of the effects of climate change on both the lake and the catchment. These variables reflect a wide range of physical, chemical, and biological responses to climate. However, the efficacy of the different indicators is affected by regional response to climate change, characteristics of the catchment, and lake mixing regimes. Thus, particular indicators or combinations of indicators are more effective for different lake types and geographic regions. The extraction of climate signals can be further complicated by the influence of other environmental changes, such as eutrophication or acidification, and the equivalent reverse phenomena, in addition to other land-use influences. In many cases, however, confounding factors can be addressed through analytical tools such as detrending or filtering. Lakes are effective sentinels for climate change because they are sensitive to climate, respond rapidly to change, and integrate information about changes in the catchment.

  • 3.
    Ahlgren, Joakim
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi.
    Reitzel, Kasper
    Tranvik, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Gogoll, Adolf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi.
    Rydin, Emil
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Degradation of organic phosphorus compounds in anoxic Baltic Sea sediments: A P-31 nuclear magnetic resonance study2006Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 51, nr 5, s. 2341-2348Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The composition and abundance of phosphorus extracted by NaOH-ethylenediaminetetraacetic acid from anoxic Northwest Baltic Sea sediment was characterized and quantified using solution P-31 nuclear magnetic resonance. Extracts from sediment depths down to 55 cm, representing 85 yr of deposition, contained 18.5 g m(-2) orthophosphate. Orthophosphate monoesters, teichoic acid P, microbial P lipids, DNA P, and pyrophosphate corresponded to 6.7, 0.3, 1.1, 3.0, and 0.03 g P m(-2), respectively. The degradability of these compound groups was estimated by their decline in concentration with sediment depth. Pyrophosphate had the shortest half-life (3 yr), followed by microbial P lipids with a half-life of 5 yr, DNA P (8 yr), and orthophosphate monoesters (16 yr). No decline in concentration with sediment depth was observed for orthophosphate or teichoic acid P.

  • 4.
    Allesson, Lina
    et al.
    Univ Oslo, Dept Biosci, Oslo, Norway..
    Koehler, Birgit
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    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 matter2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 1, s. 158-170Artikkel i tidsskrift (Fagfellevurdert)
    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.

    Fulltekst (pdf)
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  • 5.
    Balmonte, John Paul
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Hasler-Sheetal, Harald
    Univ Southern Denmark, Dept Biol, Odense, Denmark.
    Glud, Ronnie N.
    Univ Southern Denmark, Dept Biol, Odense, Denmark;Tokyo Univ Marine Sci & Technol, Dept Ocean & Environm Sci, Tokyo, Japan.
    Andersen, Thorbjörn J.
    Univ Copenhagen, Dept Geosci & Nat Resources Management, Sect Geog, Copenhagen, Denmark.
    Sejr, Mikael K.
    Aarhus Univ, Arctic Res Ctr, Aarhus, Denmark;Aarhus Univ, Dept Biosci, Silkeborg, Denmark.
    Middelboe, Mathias
    Univ Copenhagen, Marine Biol Sect, Helsingor, Denmark.
    Teske, Andreas
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Arnosti, Carol
    Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27515 USA.
    Sharp contrasts between freshwater and marine microbial enzymatic capabilities, community composition, and DOM pools in a NE Greenland fjord2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr 1, s. 77-95Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Increasing glacial discharge can lower salinity and alter organic matter (OM) supply in fjords, but assessing the biogeochemical effects of enhanced freshwater fluxes requires understanding of microbial interactions with OM across salinity gradients. Here, we examined microbial enzymatic capabilities-in bulk waters (nonsize-fractionated) and on particles (>= 1.6 mu m)-to hydrolyze common OM constituents (peptides, glucose, polysaccharides) along a freshwater-marine continuum within Tyrolerfjord-Young Sound. Bulk peptidase activities were up to 15-fold higher in the fjord than in glacial rivers, whereas bulk glucosidase activities in rivers were twofold greater, despite fourfold lower cell counts. Particle-associated glucosidase activities showed similar trends by salinity, but particle-associated peptidase activities were up to fivefold higher-or, for several peptidases, only detectable-in the fjord. Bulk polysaccharide hydrolase activities also exhibited freshwater-marine contrasts: xylan hydrolysis rates were fivefold higher in rivers, while chondroitin hydrolysis rates were 30-fold greater in the fjord. Contrasting enzymatic patterns paralleled variations in bacterial community structure, with most robust compositional shifts in river-to-fjord transitions, signifying a taxonomic and genetic basis for functional differences in freshwater and marine waters. However, distinct dissolved organic matter (DOM) pools across the salinity gradient, as well as a positive relationship between several enzymatic activities and DOM compounds, indicate that DOM supply exerts a more proximate control on microbial activities. Thus, differing microbial enzymatic capabilities, community structure, and DOM composition-interwoven with salinity and water mass origins-suggest that increased meltwater may alter OM retention and processing in fjords, changing the pool of OM supplied to coastal Arctic microbial communities.

  • 6.
    Balmonte, John Paul
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Univ North Carolina Chapel Hill, Dept Marine Sci, Chapel Hill, NC 27514 USA.;Univ Southern Denmark, Dept Biol, HADAL & Nordcee, Odense, Denmark..
    Simon, Meinhard
    Carl von Ossietzky Univ Oldenburg, Inst Chem & Biol Marine Environm, Oldenburg, Germany..
    Giebel, Helge-Ansgar
    Carl von Ossietzky Univ Oldenburg, Inst Chem & Biol Marine Environm, Oldenburg, Germany..
    Arnosti, Carol
    Univ North Carolina Chapel Hill, Dept Marine Sci, Chapel Hill, NC 27514 USA..
    A sea change in microbial enzymes: Heterogeneous latitudinal and depth-related gradients in bulk water and particle-associated enzymatic activities from 30 degrees S to 59 degrees N in the Pacific Ocean2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 9, s. 3489-3507Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Heterotrophic microbes initiate the degradation of high molecular weight organic matter using extracellular enzymes. Our understanding of differences in microbial enzymatic capabilities, especially among particle-associated taxa and in the deep ocean, is limited by a paucity of hydrolytic enzyme activity measurements. Here, we measured the activities of a broad range of hydrolytic enzymes (glucosidases, peptidases, polysaccharide hydrolases) in epipelagic to bathypelagic bulk water (nonsize-fractionated), and on particles (>= 3 mu m) along a 9800 km latitudinal transect from 30 degrees S in the South Pacific to 59 degrees N in the Bering Sea. Individual enzyme activities showed heterogeneous latitudinal and depth-related patterns, with varying biotic and abiotic correlates. With increasing latitude and decreasing temperature, lower laminarinase activities sharply contrasted with higher leucine aminopeptidase (leu-AMP) and chondroitin sulfate hydrolase activities in bulk water. Endopeptidases (chymotrypsins, trypsins) exhibited patchy spatial patterns, and their activities can exceed rates of the widely measured exopeptidase, leu-AMP. Compared to bulk water, particle-associated enzymatic profiles featured a greater relative importance of endopeptidases, as well as a broader spectrum of polysaccharide hydrolases in some locations, and latitudinal and depth-related trends that are likely consequences of varying particle fluxes. As water depth increased, enzymatic spectra on particles and in bulk water became narrower, and diverged more from one another. These distinct latitudinal and depth-related gradients of enzymatic activities underscore the biogeochemical consequences of emerging global patterns of microbial community structure and function, from surface to deep waters, and among particle-associated taxa.

    Fulltekst (pdf)
    fulltext
  • 7.
    Beier, Sara
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Bertilsson, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Uncoupling of chitinase activity and uptake of hydrolyses products in freshwater bacterioplankton2011Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, nr 4, s. 1179-1188Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated to what extent chitinolytic bacteria subsidize bacterial populations that do not produce chitinolytic enzymes but still use the products of chitin hydrolysis. Applying single-cell techniques to untreated and chitin-enriched lake water, we show that the number of planktonic cells taking up chitin hydrolysis products by far exceeds the number of cells expressing chitinases. Flavobacteria, Actinobacteria, and specifically members of the abundant and ubiquitous freshwater Ac1 cluster of the Actinobacteria, increased in abundance and were enriched in response to the chitin amendment. Flavobacteria were frequently observed in dense clusters on chitin particles, suggesting that they are actively involved in the hydrolysis and solubilization of chitin. In contrast, Actinobacteria were exclusively planktonic. We propose that planktonic Actinobacteria contain commensals specialized in the uptake of small hydrolysis products without expressing or possibly even possessing the machinery for chitin hydrolysis. More research is needed to assess the importance of such "cheater'' substrate acquisition strategies in the turnover and degradation of polymeric organic matter in aquatic ecosystems.

  • 8.
    Bertilsson, Stefan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Burgin, A.
    Carey, C.C.
    Fey, S.B.
    Grossart, H.P.
    Grubisic, L.M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Jones, I.D.
    Kirillin, G.
    Lennon, J.T.
    Shade, A.
    Smith, R.L.
    The under-ice microbiome of seasonally frozen lakes2013Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 58, nr 6, s. 1998-2012Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Compared to the well-studied open water of the ‘‘growing’’ season, under-ice conditions in lakes are characterized by low and rather constant temperature, slow water movements, limited light availability, and reduced exchange with the surrounding landscape. These conditions interact with ice-cover duration to shape microbial processes in temperate lakes and ultimately influence the phenology of community and ecosystem processes. We review the current knowledge on microorganisms in seasonally frozen lakes. Specifically, we highlight how under-ice conditions alter lake physics and the ways that this can affect the distribution and metabolism of auto- and heterotrophic microorganisms. We identify functional traits that we hypothesize are important for understanding under-ice dynamics and discuss how these traits influence species interactions. As ice coverage duration has already been seen to reduce as air temperatures have warmed, the dynamics of the under- ice microbiome are important for understanding and predicting the dynamics and functioning of seasonally frozen lakes in the near future.

  • 9. Brothers, Soren
    et al.
    Köhler, Jan
    Attermeyer, Katrin
    Grossart, Hans-Peter
    Mehner, Thomas
    Meyer, Nils
    Scharnweber, Kristin
    Hilt, Sabine
    A feedback loop links brownification and anoxia in a temperate, shallow lake2014Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 59, nr 4, s. 1388-1398Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling pathways. High precipitation for two consecutive years led to rising water levels and the flooding of adjacent degraded peatlands. Leaching from the flooded soils provided an initial increase in DOC concentrations (from a 2010 mean of 12 ± 1 mg L−1 to a maximum concentration of 53 mg L−1 by June 2012). Increasing water levels, DOC, and phytoplankton concentrations reduced light reaching the sediment surface, eliminating most benthic primary production and promoting anoxia in the hypolimnion. From January to June 2012 there was a sudden increase in total phosphorus (from 57 µg L−1 to 216 µg L−1), DOC (from 24.6 mg L−1 to 53 mg L−1), and iron (from 0.12 mg L−1 to 1.07 mg L−1) concentrations, without any further large fluxes in water levels. We suggest that anoxic conditions at the sediment surface and flooded soils produced a dramatic release of these chemicals that exacerbated brownification and eutrophication, creating anoxic conditions that persisted roughly 6 months below a water depth of 1 m and extended periodically to the water surface. This brownification-anoxia feedback loop resulted in a near-complete loss of macroinvertebrate and fish populations, and increased surface carbon dioxide (CO2) emissions by an order of magnitude relative to previous years.

  • 10. Carey, Cayelan C.
    et al.
    Rydin, Emil
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Lake trophic status can be determined by the depth distribution of sediment phosphorus2011Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, nr 6, s. 2051-2063Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In this meta-analysis, we examine how sediment phosphorus (P) burial pattern may be related to trophic state. We present sediment P profiles from 94 lakes that demonstrate fundamental differences in P burial between oligotrophic and eutrophic systems. In sediments of eutrophic (>= 30 mu g water column total P (TP) L-1) lakes, P concentrations are elevated in the surficial sediments in comparison with deeper layers, representing a large P pool that can be recycled. This pattern directly contrasts with sediment P profiles in oligotrophic lakes (< 10 mu g water column TP L-1), which exhibit increasing concentrations of permanently buried P with depth. Sediment processes regulating P burial may be important regulators of internal P recycling and consequently lake trophic status. Thus, mesotrophic lakes (10 to 30 mu g water column TP L-1), which exhibit consistent P concentrations with depth, are more vulnerable to external P inputs than oligotrophic lakes because they are at their maximal sediment P burial flux. Our data suggest that thresholds in sediment P pattern may correlate with thresholds in sediment P burial processes and consequently may indicate whether deposited P will be released to the water column.

  • 11. Casas-Ruiz, Joan P.
    et al.
    Catalan, Nuria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Gomez-Gener, Lluis
    von Schiller, Daniel
    Obrador, Biel
    Kothawala, Dolly
    Swedish University of Agricultural Sciences.
    Lopez, Pilar
    Sabater, Sergi
    Marce, Rafael
    A tale of pipes and reactors: Controls on the in-stream dynamics of dissolved organic matter in rivers2017Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 62, s. S85-S94Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The potential for rivers to alter the flux of dissolved organic matter (DOM) from land to ocean is widely accepted. Yet anticipating when and where rivers behave as active reactors vs. passive pipes of DOM stands as a major knowledge gap in river biogeochemistry, resulting in uncertainties for global carbon models. Here, we investigate the controls on in-stream DOM dynamics by evaluating changes in DOM concentration and composition along several reaches of a medium-sized river network over one full hydrological year. Roughly half of the observations over time and space showed active reactor conditions and, among these, similar pro-portion of gains and losses was measured. High water residence times promoted the active over passive behavior of the reaches, while DOM properties and nitrate availability determined whether they supplied or removed DOM from the river. Among different DOM fractions, protein-like DOM both of terrestrial and aquatic origin seemed to drive bulk DOM patterns. Our study emphasizes the role of water residence time as a physical constraint for in-stream processes, and provides new insights into the key factors governing the net balance between in-stream gains and losses of DOM in rivers.

    Fulltekst (pdf)
    fulltext
  • 12.
    Catalan, Nuria
    et al.
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona, Girona, Spain.;US Geol Survey, Boulder, CO 80303 USA.;UVSQ, CNRS, CEA, Lab Sci Climat & Environm,LSCE, Gif Sur Yvette, France..
    Pastor, Ada
    Catalan Inst Water Res ICRA, Girona, Spain.;Aarhus Univ, Dept Biosci, Aarhus, Denmark..
    Borrego, Carles M.
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona, Inst Aquat Ecol, Grp Mol Microbial Ecol, Girona, Spain..
    Casas-Ruiz, Joan Pere
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona, Inst Aquat Ecol, Res Grp Ecol Inland Waters GRECO, Girona, Spain..
    Hawkes, Jeffrey A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Gutierrez, Carmen
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona, Girona, Spain..
    von Schiller, Daniel
    Univ Barcelona, Dept Evolutionary Biol Ecol & Environm Sci, Barcelona, Spain..
    Marce, Rafael
    Catalan Inst Water Res ICRA, Girona, Spain.;Univ Girona, Girona, Spain..
    The relevance of environment vs. composition on dissolved organic matter degradation in freshwaters2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 2, s. 306-320Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dissolved organic matter (DOM) composition exerts a direct control on its degradation and subsequent persistence in aquatic ecosystems. Yet, under certain conditions, the degradation patterns of DOM cannot be solely explained by its composition, highlighting the relevance of environmental conditions for DOM degradation. Here, we experimentally assessed the relative influence of composition vs. environment on DOM degradation by performing degradation bioassays using three contrasting DOM sources inoculated with a standardized bacterial inoculum under five distinct environments. The DOM degradation kinetics modeled using reactivity continuum models showed that composition was more important than environment in determining the bulk DOM decay patterns. Changes in DOM composition resulted from the interaction between DOM source and environment. The role of environment was stronger on shaping the bacterial community composition, but the intrinsic nature of the DOM source exerted stronger control on the DOM degradation function.

    Fulltekst (pdf)
    fulltext
  • 13.
    Catalán, Núria
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Kellerman, Anne M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Peter, Hannes
    Carmona, Francesc
    Tranvik, Lars J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Absence of a priming effect on dissolved organic carbon degradation in lake water2015Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 60, nr 1, s. 159-168Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The idea that small amounts of labile organic carbon might trigger the degradation of previously unreactive organic matter has attracted increasing scientific interest across multiple disciplines. Although this phenomenon, referred to as priming, has been widely reported in soils, evidence in freshwater systems is scarce and inconclusive. Here, we use a multifactorial microcosm experiment to test the conditions under which priming may be observed in freshwater ecosystems. We assessed the effect of pulse additions of three labile carbon sources (acetate, glucose, and cellobiose) on dissolved organic carbon (DOC) consumption using water from lakes with different trophic states (eutrophic to oligotrophic and clear to brownwater lakes). We further analyzed the effect of nutrient availability and the role of attachment of cells to surfaces. Despite the range of conditions tested, we found no clear evidence of a priming effect on DOC degradation, indicating that priming in freshwater systems may be of limited importance.

    Fulltekst (pdf)
    fulltext
  • 14.
    Chmiel, Hannah E.
    et al.
    Physics of Aquatic Systems Laboratory, Margaretha Kamprad Chair, ENAC, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Limnology Center, ENAC, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
    Hofmann, Hilmar
    Environmental Physics Group, Limnological Institute, University of Konstanz, Konstanz, Germany.
    Sobek, Sebastian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Efremova, Tatyana
    Northern Water Problems Institute, Karelian Research Centre, Russian Academy of Sciences, Petrozavodsk, Russia.
    Pasche, Natacha
    Physics of Aquatic Systems Laboratory, Margaretha Kamprad Chair, ENAC, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland; Limnology Center, ENAC, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
    Where does the river end?: Drivers of spatiotemporal variability in CO2 concentration and flux in the inflow area of a large boreal lake2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr 6, s. 1161-1174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    River inflow affects the spatiotemporal variability of carbon dioxide (CO2) in the water column of lakes and may locally influence CO2 gas exchange with the atmosphere. However, spatiotemporal CO2 variability at river inflow sites is often unknown leaving estimates of lake‐wide CO2 emission uncertain. Here, we investigated the CO2 concentration and flux variability along a river‐impacted bay and remote sampling locations of Lake Onego. During 3 years, we resolved spatial CO2 gradients between river inflow and central lake and recorded the temporal course of CO2 in the bay from the ice‐covered period to early summer. We found that the river had a major influence on the spatial CO2 variability during ice‐covered periods and contributed ~ 35% to the total amount of CO2 in the bay. The bay was a source of CO2 to the atmosphere at ice‐melt each year emitting 2–15 times the amount as an equally sized area in the central lake. However, there was large interannual variability in the spring CO2 emission from the bay related to differences in discharge and climate that affected the hydrodynamic development of the lake during spring. In early summer, the spatial CO2 variability was unrelated to the river signal but correlated negatively with dissolved oxygen concentrations instead indicating a stronger biological control on CO2. Our study reveals a large variability of CO2 and its drivers at river inflow sites at the seasonal and at the interannual time scale. Understanding these dynamics is essential for predicting lake‐wide CO2 fluxes more accurately under a warming climate.

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  • 15.
    Chmiel, Hannah Elisa
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Kokic, Jovana
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Denfeld, Blaize Amber
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Einarsdóttir, Karólina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Wallin, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Köhler, Birgit
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Isidorova, Anastasija
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Bastviken, David
    Linköping University.
    Ferland, Marie-Ève
    Université du Québec à Montréal, Québec, Canada.
    Sobek, Sebastian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    The role of sediments in the carbon budget of a small boreal lake2016Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 61, nr 5, s. 1814-1825Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated the role of lake sediments as carbon (C) source and sink in the annual C budget of a small (0.07 km2), shallow (mean depth 3.4 m), and humic lake (mean DOC concentration 17 mg L-1) in boreal Sweden. Organic carbon (OC) burial and mineralization in sediments were quantified from 210Pb-dated sediment and laboratory sediment incubation experiments, respectively, and upscaled to the entire basin and to one whole year, by using sediment thickness derived sub-bottom profiling, basin morphometry, and water column monitoring data of temperature and oxygen concentration. Furthermore, catchment C import, open water metabolism, photochemical mineralization as well as carbon dioxide (CO2) and methane (CH4) emissions to the atmosphere, were quantified to relate sediment processes to other lake C fluxes. We found that on a whole-basin and annual scale, sediment OC mineralization was three times larger than OC burial, and contributed about 16% to the annual CO2 emission from the lake to the atmosphere. Remaining contributions to the CO2 emission were attributed to water column metabolism (31%), photochemical mineralization (6%), and catchment imports via inlet streams and inflow of shallow groundwater (47%). We conclude that on an annual and whole-basin scale 1) sediment OC mineralization dominated over OC burial, 2) water column OC mineralization contributed more than sediments to lake CO2 emission, and 3) catchment import of C to the lake was greater than lake-internal C cycling. 

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  • 16.
    Christaki, Urania
    et al.
    Univ. Littoral Côte d'Opale ULCO, CNRS, Univ. Lille, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, F‐Code postal Ville, France.
    Gueneugues, Audrey
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Liu, Yan
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Blain, Stéphane
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Catala, Philippe
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Colombet, Jonathan
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Debeljak, Pavla
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Jardillier, Ludwig
    Unité d'Ecologie, Systématique et Evolution, Université Paris‐Sud, CNRS, AgroParisTech, Université Paris‐Saclay, Orsay Cedex, France.
    Irion, Solène
    Univ. Littoral Côte d'Opale ULCO, CNRS, Univ. Lille, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, F‐Code postal Ville, France.
    Planchon, Fred
    University of Brest, Laboratoire des Sciences de l'Environnement (LEMAR), UMR6539 CNRS/UBO/IFREMER/IRD, Technopôle Brest Iroise, Plouzané, France.
    Sassenhagen, Ingrid
    Univ. Littoral Côte d'Opale ULCO, CNRS, Univ. Lille, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, F‐Code postal Ville, France.
    Sime-Ngando, Telesphore
    Laboratoire Microorganismes: Génome et Environnement (LMGE), UMR CNRS 6023, Clermont Université Blaise Pascal, Aubière Cedex, France.
    Obernosterer, Ingrid
    Sorbonne Université, CNRS, Laboratoire d'Océanographie Microbienne (LOMIC), Banyuls‐sur‐Mer, France.
    Seasonal microbial food web dynamics in contrasting Southern Ocean productivity regimes2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 1, s. 108-122Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spatial and seasonal dynamics of microbial loop fluxes were investigated in contrasting productivity regimes in the Indian sector of the Southern Ocean. Observations carried out in late summer (February-?March 2018; project MOBYDICK) revealed higher microbial biomasses and fluxes in the naturally iron-fertilized surface waters of Kerguelen island in comparison to surrounding off-plateau waters. Differences were most pronounced for bacterial heterotrophic production (2.3-fold), the abundance of heterotrophic nanoflagellates (HNF; 2.7-fold). Independent of site, grazing by HNF was the main loss process of bacterial production (80-100%), while virus-induced mortality was low (<9%). Combining these results with observations from previous investigations during early spring and summer allowed us to describe seasonal patterns in microbial food web fluxes and to compare these to carbon export in the iron-fertilized and high-nutrient, low-chlorophyll (HNLC) Southern Ocean. Our data suggest an overall less efficient microbial food web during spring and summer, when respiration and viral lysis, respectively, represent important loss terms of bacterially-mediated carbon. In late summer, primary production is more efficiently transferred to bacterial biomass and HNF and thus available for higher trophic levels. These results provide a new insight into the seasonal variability and the quantitative importance of microbial food web processes for the fate of primary production in the Southern Ocean.

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  • 17. de Melo, Michaela L.
    et al.
    Kothawala, Dolly
    Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Bertilsson, Stefan
    Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Amaral, João Henrique
    Forsberg, Bruce
    Sarmento, Hugo
    Linking dissolved organic matter composition and bacterioplankton communities in an Amazon floodplain system2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr 1, s. 63-76Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dissolved organic matter (DOM) is the main substrate for aquatic prokaryotes, fuelling their metabolism and controlling community composition. Amazonian rivers transport and process large fluxes of terrestrial DOM, but little is known about the link between DOM composition and heterotrophic bacteria in the Amazon basin. The aims of this study were to characterize DOM composition and investigate the coupling between DOM and bacterial community composition (BCC) during a complete hydrological cycle in an Amazon floodplain system (lake Janauacá). Our study revealed a clear seasonal pattern in DOM composition through the flood pulse, which affected the amounts of autochthonous and allochthonous inputs and consequently the extent of humification, molecular weight, and aromaticity of the DOM. BCC was tightly coupled to DOM fluorescence, which was also driven by differences over the hydrological cycle, with distinct components and operational taxonomic units being simultaneously more abundant and correlating with a specific season. This coupling was particularly well reflected for three of the four identified fluorescence components, two terrestrial humic-like components (C1 and C3) and an autochthonous component (C4). Despite clear changes in DOM composition, dissolved organic carbon concentrations tended to be relatively stable throughout the year. Overall, our results suggest that BCC shifts were associated with DOM quality but not with its quantity (that remains relatively constant throughout the year), and that bacteria preferably use labile and freshly produced DOM in lake Janauacá.

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  • 18. Dokulil, Martin T.
    et al.
    Jagsch, Albert
    George, Glen D.
    Anneville, Orlane
    Jankowski, Thomas
    Wahl, Bernd
    Lenhart, Brigitte
    Blenckner, Thorsten
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper.
    Teubner, Katrin
    Twenty years of spatially coherent deepwater warming in lakes across Europe related to the North Atlantic Oscillation2006Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 51, nr 6, s. 2787-2793Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Twenty to fifty years of annual mean deepwater (hypolimnetic) temperature data from twelve deep lakes spaced across Europe (2 degrees 95'W to 14 degrees 0'E, 46 degrees 27' to 59 degrees 00'N) show a high degree of coherence among lakes, particularly within geographic regions. Hypolimnetic temperatures vary between years but increased consistently in all lakes by about 0.1 - 0.2 degrees C per decade. The observed increase was related to the weather generated by large-scale climatic processes over the Atlantic. To be effective, the climatic signal from the North Atlantic Oscillation (NAO) must affect deep lakes in spring before the onset of thermal stratification. The most consistent predictor of hypolimnetic temperature is the mean NAO index for January-May (NAO(J-M)), which explains 22-63% of the interannual variation in deepwater temperature in 10 of the 12 lakes. The two exceptions are remote, less wind-exposed alpine valley lakes. In four of the deepest lakes, the climate signal fades with depth. The projected hypolimnetic temperature increase of approximately 1 degrees C in 100 yr, obtained using a conservative approach, seems small. Effects on mixing conditions, thermal stability, or the replenishment of oxygen to deep waters result in accumulation of nutrients, which in turn will affect the trophic status and the food web.

  • 19.
    Donis, Daphne
    et al.
    Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.;Univ Geneva, Inst Environm Sci, Geneva, Switzerland..
    Mantzouki, Evanthia
    Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.;Univ Geneva, Inst Environm Sci, Geneva, Switzerland..
    McGinnis, Daniel F.
    Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.;Univ Geneva, Inst Environm Sci, Geneva, Switzerland..
    Vachon, Dominic
    Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.;Univ Geneva, Inst Environm Sci, Geneva, Switzerland.;Umeå Univ, Dept Ecol & Environm Sci, Umeå, Sweden..
    Gallego, Irene
    Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.;Univ Geneva, Inst Environm Sci, Geneva, Switzerland.;Eawag, Dept Aquat Ecol, Uberlandstr, Dubendorf, Switzerland..
    Grossart, Hans-Peter
    Leibniz Inst Freshwater Ecol & Inland Fisheries, Dept Expt Limnol, Stechlin, Germany.;Potsdam Univ, Inst Biochem & Biol, Potsdam, Germany..
    Domis, Lisette N. de Senerpont
    Netherlands Inst Ecol NIOO KNAW, Dept Aquat Ecol, Wageningen, Netherlands.;Wageningen Univ, Dept Environm Sci, Aquat Ecol & Water Qual Management Grp, NL-6708 PB Wageningen, Netherlands..
    Teurlincx, Sven
    Netherlands Inst Ecol NIOO KNAW, Dept Aquat Ecol, Wageningen, Netherlands..
    Seelen, Laura
    Netherlands Inst Ecol NIOO KNAW, Dept Aquat Ecol, Wageningen, Netherlands.;Wageningen Univ, Dept Environm Sci, Aquat Ecol & Water Qual Management Grp, NL-6708 PB Wageningen, Netherlands..
    Lurling, Miquel
    Netherlands Inst Ecol NIOO KNAW, Dept Aquat Ecol, Wageningen, Netherlands.;Wageningen Univ & Res, Dept Environm Sci, Wageningen, Netherlands..
    Verstijnen, Yvon
    Wageningen Univ & Res, Dept Environm Sci, Wageningen, Netherlands..
    Maliaka, Valentini
    Wageningen Univ & Res, Dept Environm Sci, Wageningen, Netherlands.;Soc Protect Prespa, Agios Germanos, Greece.;Radboud Univ Nijmegen, Inst Water & Wetland Res, Dept Aquat Ecol & Environm Biol, Nijmegen, Netherlands..
    Fonvielle, Jeremy
    Leibniz Inst Freshwater Ecol & Inland Fisheries, Dept Expt Limnol, Stechlin, Germany..
    Visser, Petra M.
    Univ Amsterdam, Inst Biodivers & Ecosyst Dynam, Dept Freshwater & Marine Ecol, Amsterdam, Netherlands..
    Verspagen, Jolanda
    Univ Amsterdam, Inst Biodivers & Ecosyst Dynam, Dept Freshwater & Marine Ecol, Amsterdam, Netherlands..
    van Herk, Maria
    Univ Amsterdam, Inst Biodivers & Ecosyst Dynam, Dept Freshwater & Marine Ecol, Amsterdam, Netherlands..
    Antoniou, Maria G.
    Cyprus Univ Technol, Dept Chem Engn, Lemesos, Cyprus..
    Tsiarta, Nikoletta
    Cyprus Univ Technol, Dept Chem Engn, Lemesos, Cyprus..
    McCarthy, Valerie
    Dundalk Inst Technol, Ctr Freshwater & Environm Studies, Dundalk, Ireland..
    Perello, Victor C.
    Dundalk Inst Technol, Ctr Freshwater & Environm Studies, Dundalk, Ireland..
    Machado-Vieira, Danielle
    Univ Fed Paraiba, Dept Sistemat & Ecol, Joao Pessoa, Paraiba, Brazil..
    de Oliveira, Alinne Gurjao
    Univ Fed Paraiba, Dept Sistemat & Ecol, Joao Pessoa, Paraiba, Brazil..
    Maronic, Dubravka Spoljaric
    Josip Juraj Strossmayer Univ Osijek, Dept Biol, Osijek, Croatia..
    Stevic, Filip
    Josip Juraj Strossmayer Univ Osijek, Dept Biol, Osijek, Croatia..
    Pfeiffer, Tanja Zuna
    Josip Juraj Strossmayer Univ Osijek, Dept Biol, Osijek, Croatia..
    Vucelic, Itana Bokan
    Teaching Inst Publ Hlth Primorje Gorski Kotar Cty, Dept Ecotoxicol, Rijeka, Croatia..
    Zutinic, Petar
    Univ Zagreb, Fac Sci, Dept Biol, Zagreb, Croatia..
    Udovic, Marija Gligora
    Univ Zagreb, Fac Sci, Dept Biol, Zagreb, Croatia..
    Blaha, Ludek
    Masaryk Univ, Fac Sci, RECETOX, Brno, Czech Republic..
    GeriS, Rodan
    Morava Board Author, Dept Hydrobiol, Brno, Czech Republic..
    Fankova, Marketa
    Czech Acad Sci, Inst Bot, Dept Paleoecol, Brno, Czech Republic..
    Christoffersen, Kirsten Seestern
    Univ Copenhagen, Dept Biol, Freshwater Biol Lab, Copenhagen, Denmark..
    Warming, Trine Perlt
    Univ Copenhagen, Dept Biol, Freshwater Biol Lab, Copenhagen, Denmark..
    Feldmann, Tonu
    Estonian Univ Life Sci, Inst Agr & Environm Sci, Tartu, Estonia..
    Laas, Alo
    Estonian Univ Life Sci, Inst Agr & Environm Sci, Tartu, Estonia..
    Panksep, Kristel
    Estonian Univ Life Sci, Inst Agr & Environm Sci, Tartu, Estonia..
    Tuvikene, Lea
    Estonian Univ Life Sci, Inst Agr & Environm Sci, Tartu, Estonia..
    Kangro, Kersti
    Estonian Univ Life Sci, Inst Agr & Environm Sci, Tartu, Estonia.;Univ Tartu, Fac Sci & Technol, Tartu Observ, Tartu, Estonia..
    Koreiviene, Judita
    Nat Res Ctr, Inst Bot, Vilnius, Lithuania..
    Karosiene, Jurate
    Nat Res Ctr, Inst Bot, Vilnius, Lithuania..
    Kasperoviciene, Jurate
    Nat Res Ctr, Inst Bot, Vilnius, Lithuania..
    Savadova-Ratkus, Ksenija
    Nat Res Ctr, Inst Bot, Vilnius, Lithuania..
    Vitonyte, Irma
    Nat Res Ctr, Inst Bot, Vilnius, Lithuania..
    Haggqvist, Kerstin
    Abo Akad Univ, Dept Sci & Engn, Turku, Finland..
    Salmi, Pauliina
    Univ Jyvaskyla, Dept Biol & Environm Sci, Jyvaskyla, Finland..
    Arvola, Lauri
    Univ Helsinki, Lammi Biol Stn, Lammi, Finland..
    Rothhaupt, Karl
    Univ Konstanz, Limnol Inst, Dept Biol, Constance, Germany..
    Avagianos, Christos
    Athens Water Supply & Sewerage Co, Water Qual Dept, Athens, Greece..
    Kaloudis, Triantafyllos
    Athens Water Supply & Sewerage Co, Water Qual Dept, Athens, Greece..
    Gkelis, Spyros
    Aristotle Univ Thessaloniki, Sch Biol, Dept Bot, Thessaloniki, Greece..
    Panou, Manthos
    Aristotle Univ Thessaloniki, Sch Biol, Dept Bot, Thessaloniki, Greece..
    Triantis, Theodoros
    Natl Ctr Sci Res DEMOKRITOS, Inst Nanosci & Nanotechnol, Athens, Greece..
    Zervou, Sevasti-Kiriaki
    Natl Ctr Sci Res DEMOKRITOS, Inst Nanosci & Nanotechnol, Athens, Greece..
    Hiskia, Anastasia
    Natl Ctr Sci Res DEMOKRITOS, Inst Nanosci & Nanotechnol, Athens, Greece..
    Obertegger, Ulrike
    Fdn Edmund Mach, Res & Innovat Ctr, I-38010 San Michele All Adige, Italy..
    Boscaini, Adriano
    Fdn Edmund Mach, Res & Innovat Ctr, I-38010 San Michele All Adige, Italy..
    Flaim, Giovanna
    Fdn Edmund Mach, Res & Innovat Ctr, I-38010 San Michele All Adige, Italy..
    Salmaso, Nico
    Fdn Edmund Mach, Res & Innovat Ctr, I-38010 San Michele All Adige, Italy..
    Cerasino, Leonardo
    Fdn Edmund Mach, Res & Innovat Ctr, I-38010 San Michele All Adige, Italy..
    Haande, Sigrid
    Norwegian Inst Water Res, Dept Freshwater Ecol, Oslo, Norway..
    Skjelbred, Birger
    Norwegian Inst Water Res, Dept Freshwater Ecol, Oslo, Norway..
    Grabowska, Magdalena
    Univ Bialystok, Dept Hydrobiol, Bialystok, Poland..
    Karpowicz, Maciej
    Univ Bialystok, Dept Hydrobiol, Bialystok, Poland..
    Chmura, Damian
    Univ Bielsko Biala, Inst Environm Protect & Engn, Bielsko Biala, Poland..
    Nawrocka, Lidia
    State Univ Appl Sci, Inst Technol, Elblag, Poland..
    Kobos, Justyna
    Univ Gdansk, Dept Marine Biotechnol, Gdynia, Poland..
    Mazur-Marzec, Hanna
    Univ Gdansk, Dept Marine Biotechnol, Gdynia, Poland..
    Alcaraz-Parraga, Pablo
    Univ Jaen, Dept Anim Biol Plant Biol & Ecol, Jaen, Spain..
    Wilk-Wozniak, Elzbieta
    Polish Acad Sci, Inst Nat Conservat, Krakow, Poland..
    Krzton, Wojciech
    Polish Acad Sci, Inst Nat Conservat, Krakow, Poland..
    Walusiak, Edward
    Polish Acad Sci, Inst Nat Conservat, Krakow, Poland..
    Gagala-Borowska, Ilona
    Polish Acad Sci, European Reg Ctr Ecohydrol, Lodz, Poland..
    Mankiewicz-Boczek, Joana
    Polish Acad Sci, European Reg Ctr Ecohydrol, Lodz, Poland..
    Toporowska, Magdalena
    Univ Life Sci Lublin, Dept Hydrobiol & Protect Ecosyst, Lublin, Poland..
    Pawlik-Skowronska, Barbara
    Univ Life Sci Lublin, Dept Hydrobiol & Protect Ecosyst, Lublin, Poland..
    Niedzwiecki, Michal
    Univ Life Sci Lublin, Dept Hydrobiol & Protect Ecosyst, Lublin, Poland..
    Napiorkowska-Krzebietke, Agnieszka
    S Sakowicz Inland Fisheries Inst, Dept Ichthyol Hydrobiol & Aquat Ecol, PL-10719 Olsztyn, Poland..
    Dunalska, Julita
    Univ Warmia & Mazury, Dept Water Protect Engn, Olsztyn, Poland..
    Sienska, Justyna
    Univ Warmia & Mazury, Dept Water Protect Engn, Olsztyn, Poland..
    Szymanski, Daniel
    Univ Warmia & Mazury, Dept Water Protect Engn, Olsztyn, Poland..
    Kruk, Marek
    Univ Warmia & Mazury, Dept Appl Comp Sci & Math Modelling, PL-10710 Olsztyn, Poland..
    Budzynska, Agnieszka
    Adam Mickiewicz Univ, Fac Biol, Dept Water Protect, Poznan, Poland..
    Goldyn, Ryszard
    Adam Mickiewicz Univ, Fac Biol, Dept Water Protect, Poznan, Poland..
    Kozak, Anna
    Adam Mickiewicz Univ, Fac Biol, Dept Water Protect, Poznan, Poland..
    Rosinska, Joanna
    Adam Mickiewicz Univ, Fac Biol, Dept Water Protect, Poznan, Poland..
    Domek, Piotr
    Adam Mickiewicz Univ, Fac Biol, Dept Water Protect, Poznan, Poland..
    Jakubowska-Krepska, Natalia
    Adam Mickiewicz Univ, Fac Biol, Dept Water Protect, Poznan, Poland..
    Kwasizur, Kinga
    Adam Mickiewicz Univ, Fac Biol, Dept Hydrobiol, Poznan, Poland..
    Messyasz, Beata
    Adam Mickiewicz Univ, Fac Biol, Dept Hydrobiol, Poznan, Poland..
    Kokocinski, Mikolaj
    Adam Mickiewicz Univ, Fac Biol, Dept Hydrobiol, Poznan, Poland..
    Madrecka-Witkowska, Beata
    Poznan Univ Tech, Fac Environm Engn & Energy, Inst Environm Engn & Bldg Installat, PL-60965 Poznan, Poland..
    Kostrzewska-Szlakowska, Iwona
    Univ Warsaw, Fac Biol, Warsaw, Poland..
    Frak, Magdalena
    Warsaw Univ Life Sci SGGW, Inst Environm Engn, Dept Remote Sensing & Environm Assessment, Nowoursynowska Str 166, PL-02787 Warsaw, Poland..
    Bankowska-Sobczak, Agnieszka
    Warsaw Univ Life Sci SGGW, Fac Civil & Environm Engn, Dept Water Engn & Appl Geol, PL-02787 Warsaw, Poland..
    Wasilewicz, Michal
    Warsaw Univ Life Sci SGGW, Fac Civil & Environm Engn, Dept Water Engn & Appl Geol, PL-02787 Warsaw, Poland..
    Ochocka, Agnieszka
    Inst Environm Protect, Dept Freshwater Protect, Natl Res Inst, Warsaw, Poland..
    Pasztaleniec, Agnieszka
    Inst Environm Protect, Dept Freshwater Protect, Natl Res Inst, Warsaw, Poland..
    Jasser, Iwona
    Univ Warsaw, Fac Biol, Dept Plant Ecol & Environm Conservat, PL-02089 Warsaw, Poland..
    Antao-Geraldes, Ana M.
    Inst Politecn Braganca, Ctr Invest Montanha CIMO, Braganca, Portugal..
    Leira, Manel
    Univ A Coruna, Fac Sci, BioCost Res Grp, La Coruna 15071, Spain.;Univ A Coruna, Fac Sci, Dept Biol, Ctr Invest Cient Avanzadas CICA, La Coruna 15071, Spain..
    Vasconcelos, Vitor
    Univ Porto, Interdisciplinary Ctr Marine & Environm Res CIIMA, P-4450208 Matosinhos, Portugal..
    Morais, Joao
    Univ Porto, Interdisciplinary Ctr Marine & Environm Res CIIMA, P-4450208 Matosinhos, Portugal..
    Vale, Micaela
    Univ Porto, Interdisciplinary Ctr Marine & Environm Res CIIMA, P-4450208 Matosinhos, Portugal..
    Raposeiro, Pedro M.
    Univ Azores, Fac Sci & Technol, Res Ctr Biodivers & Genet Resources CIBIO Azores, InBIO Associated Lab, P-9500321 Ponta Delgada, Portugal..
    Goncalves, Vitor
    Univ Azores, Fac Sci & Technol, Res Ctr Biodivers & Genet Resources CIBIO Azores, InBIO Associated Lab, P-9500321 Ponta Delgada, Portugal..
    Aleksovski, Boris
    SS Cyril & Methodius Univ, Fac Nat Sci & Math, Skopje, North Macedonia..
    Krstic, Svetislav
    SS Cyril & Methodius Univ, Fac Nat Sci & Math, Skopje, North Macedonia..
    Nemova, Hana
    Publ Hlth Author Slovak Republ, Natl Reference Ctr Hydrobiol, Bratislava, Slovakia..
    Drastichova, Iveta
    Publ Hlth Author Slovak Republ, Natl Reference Ctr Hydrobiol, Bratislava, Slovakia..
    Chomova, Lucia
    Publ Hlth Author Slovak Republ, Natl Reference Ctr Hydrobiol, Bratislava, Slovakia..
    Remec-Rekar, Spela
    Slovenian Environm Agcy, Dept Water Qual, Ljubljana, Slovenia..
    Elersek, Tina
    Natl Inst Biol, Dept Genet Toxicol & Canc Biol, Ljubljana, Slovenia..
    Hansson, Lars-Anders
    Lund Univ, Dept Biol, Lund, Sweden..
    Urrutia Cordero, Pablo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Lund Univ, Dept Biol, Lund, Sweden..
    Bravo, Andrea Garcia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Buck, Moritz
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Colom-Montero, William
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Mustonen, Kristiina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Pierson, Don
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Yang, Yang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Richardson, Jessica
    Univ Stirling, Dept Biol & Environm Sci, Stirling, Scotland..
    Edwards, Christine
    Robert Gordon Univ, Sch Pharm & Life Sci, Aberdeen, Scotland..
    Cromie, Hannah
    Agrifood & Biosci Inst, Belfast, Antrim, North Ireland..
    Delgado-Martin, Jordi
    Univ A Coruna, Dept Civil Engn, La Coruna, Spain..
    Garcia, David
    Univ A Coruna, Dept Civil Engn, La Coruna, Spain..
    Luis Cereijo, Jose
    Univ A Coruna, Dept Civil Engn, La Coruna, Spain..
    Goma, Joan
    Univ Barcelona, Dept Evolutionary Biol Ecol & Environm Sci, Barcelona, Spain..
    Carmen Trapote, Mari
    Univ Barcelona, Dept Evolutionary Biol Ecol & Environm Sci, Barcelona, Spain..
    Vegas-Vilarrubia, Teresa
    Univ Barcelona, Dept Evolutionary Biol Ecol & Environm Sci, Barcelona, Spain..
    Obrador, Biel
    Univ Barcelona, Dept Evolutionary Biol Ecol & Environm Sci, Barcelona, Spain..
    Garcia-Murcia, Ana
    AECOM URS, Dept Limnol & Water Qual, Barcelona, Spain..
    Real, Monserrat
    AECOM URS, Dept Limnol & Water Qual, Barcelona, Spain..
    Romans, Elvira
    AECOM URS, Dept Limnol & Water Qual, Barcelona, Spain..
    Noguero-Ribes, Jordi
    AECOM URS, Dept Limnol & Water Qual, Barcelona, Spain..
    Duque, David Parreno
    AECOM URS, Dept Limnol & Water Qual, Barcelona, Spain..
    Fernandez-Moran, Elisabeth
    AECOM URS, Dept Limnol & Water Qual, Barcelona, Spain..
    Ubeda, Barbara
    Univ Cadiz, INMAR Marine Res Inst, Dept Biol, Puerto Real 11510, Spain..
    Galvez, Jose Angel
    Univ Cadiz, INMAR Marine Res Inst, Dept Biol, Puerto Real 11510, Spain..
    Catalan, Nuria
    Catalan Inst Water Res ICRA, Girona, Spain..
    Perez-Martinez, Carmen
    Univ Granada, Dept Ecol, Granada, Spain.;Univ Granada, Inst Water Res, Granada, Spain..
    Ramos-Rodriguez, Eloisa
    Univ Granada, Dept Ecol, Granada, Spain.;Univ Granada, Inst Water Res, Granada, Spain..
    Cillero-Castro, Carmen
    3Edata, R&D Dept Environm Engn, Lugo, Spain..
    Moreno-Ostos, Enrique
    Univ Malaga, Dept Ecol, Malaga, Spain..
    Maria Blanco, Jose
    Univ Malaga, Dept Ecol, Malaga, Spain..
    Rodriguez, Valeriano
    Univ Malaga, Dept Ecol, Malaga, Spain..
    Juan Montes-Perez, Jorge
    Univ Malaga, Dept Ecol, Malaga, Spain..
    Palomino, Roberto L.
    Univ Malaga, Dept Ecol, Malaga, Spain..
    Rodriguez-Perez, Estela
    Univ Malaga, Dept Ecol, Malaga, Spain..
    Hernandez, Armand
    CSIC, Inst Earth Sci Jaume Almera, ICTJA, Barcelona, Spain..
    Carballeira, Rafael
    Univ A Coruna, Fac Ciencias, Ctr Invest Cient Avanzadas CICA, La Coruna, Spain..
    Camacho, Antonio
    Univ Valencia, Cavanilles Inst Biodivers & Evolutionary Biol, Valencia, Spain..
    Picazo, Antonio
    Univ Valencia, Cavanilles Inst Biodivers & Evolutionary Biol, Valencia, Spain..
    Rochera, Carlos
    Univ Valencia, Cavanilles Inst Biodivers & Evolutionary Biol, Valencia, Spain..
    Santamans, Anna C.
    Univ Valencia, Cavanilles Inst Biodivers & Evolutionary Biol, Valencia, Spain..
    Ferriol, Carmen
    Univ Valencia, Cavanilles Inst Biodivers & Evolutionary Biol, Valencia, Spain..
    Romo, Susana
    Univ Valencia, Dept Microbiol & Ecol, Burjassot, Spain..
    Miguel Soria, Juan
    Univ Valencia, Dept Microbiol & Ecol, Burjassot, Spain..
    Ozen, Arda
    Univ Cankiri Karatekin, Dept Forest Engn, Cankiri, Turkey..
    Karan, Tunay
    Yozgat Bozok Univ, Fac Vet Med, Dept Anim Nutr & Zootech, Yozgat, Turkey..
    Demir, Nilsun
    Ankara Univ, Dept Fisheries & Aquaculture Engn, TR-06110 Ankara, Turkey..
    Beklioglu, Meryem
    Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey..
    Filiz, Nur
    Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey..
    Levi, Eti
    Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey..
    Iskin, Ugur
    Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey..
    Bezirci, Gizem
    Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey..
    Tavsanoglu, Ulku Nihan
    Middle East Tech Univ, Dept Biol Sci, Limnol Lab, Ankara, Turkey..
    Celik, Kemal
    Balikesir Univ, Dept Biol, Balikesir, Turkey..
    Ozhan, Koray
    Middle East Tech Univ, Inst Marine Sci, Dept Oceanog, Ankara, Turkey..
    Karakaya, Nusret
    Abant Izzet Baysal Univ, Dept Environm Engn, Bolu, Turkey..
    Kocer, Mehmet Ali Turan
    Mediterranean Fisheries Res Prod & Training Inst, Dept Environm & Resource Management, Antalya, Turkey..
    Yilmaz, Mete
    Bursa Tech Univ, Dept Bioengn, Bursa, Turkey..
    Maraslioglu, Faruk
    Hitit Univ, Dept Biol, Corum, Turkey..
    Soylu, Elif Neyran
    Giresun Univ, Dept Biol, Giresun, Turkey..
    Fakioglu, Ozden
    Ataturk Univ, Dept Basic Sci, Erzurum, Turkey..
    Yagci, Meral Apaydin
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Cinar, Sakir
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Capkin, Kadir
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Yagci, Abdulkadir
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Cesur, Mehmet
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Bilgin, Fuat
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Bulut, Cafer
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Uysal, Rahmi
    Republ Turkey Minist Food Agr, Fisheries Res Inst, Isparta, Turkey..
    Latife, Koker
    Istanbul Univ, Fac Aquat Sci, Dept Freshwater Resource & Management, Istanbul, Turkey..
    Akcaalan, Reyhan
    Istanbul Univ, Fac Aquat Sci, Dept Freshwater Resource & Management, Istanbul, Turkey..
    Albay, Meric
    Istanbul Univ, Fac Aquat Sci, Dept Freshwater Resource & Management, Istanbul, Turkey..
    Alp, Mehmet Tahir
    Mersin Univ, Fac Aquaculture, Mersin, Turkey..
    Ozkan, Korhan
    Middle East Tech Univ, Inst Marine Sci Marine Biol & Fisheries, Mersin, Turkey..
    Sevindik, Tugba Ongun
    Sakarya Univ, Dept Biol, Sakarya, Turkey..
    Tunca, Hatice
    Sakarya Univ, Dept Biol, Sakarya, Turkey..
    Onem, Burcin
    Sakarya Univ, Dept Biol, Sakarya, Turkey..
    Paerl, Hans
    Univ N Carolina, Inst Marine Sci, Chapel Hill, NC USA..
    Carey, Cayelan C.
    Virginia Tech, Dept Biol Sci, Blacksburg, VA USA..
    Ibelings, Bastiaan W.
    Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.;Univ Geneva, Inst Environm Sci, Geneva, Switzerland..
    Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 12, s. 4314-4333Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.

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  • 20.
    Doubek, Jonathan P.
    et al.
    Univ Vermont, Rubenstein Ecosyst Sci Lab, Burlington, VT 05405 USA.;Lake Super State Univ, Sch Nat Resources & Environm, Sault Sainte Marie, MI 49783 USA.;Lake Super State Univ, Ctr Freshwater Res & Educ, Sault Sainte Marie, MI 49783 USA..
    Anneville, Orlane
    Univ Savoie Mont Blanc, Inst Natl Rech Agr Alimentat & Environm INRAE, CARRTEL, Thonon Les Bains, France..
    Dur, Gael
    Shizuoka Univ, Creat Sci Unit Geosci, Fac Sci, Shizuoka, Japan..
    Lewandowska, Aleksandra M.
    Univ Helsinki, Tvarminne Zool Stn, Hango, Finland..
    Patil, Vijay P.
    US Geol Survey, Alaska Sci Ctr, Anchorage, AK USA..
    Rusak, James A.
    Ontario Minist Environm Conservat & Pk, Dorset Environm Sci Ctr, Toronto, ON, Canada.;Queens Univ, Dept Biol, Kingston, ON, Canada..
    Salmaso, Nico
    Fdn Edmund Mach, Dept Sustainable Agroecosyst & Bioresources, Res & Innovat Ctr, San Michele All Adige, Italy..
    Seltmann, Christian Torsten
    Competence Ctr Wood & Forestry, Publ Enterprise Sachsenforst, Pirna, Germany..
    Straile, Dietmar
    Univ Konstanz, Limnol Inst, Constance, Germany..
    Urrutia Cordero, Pablo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Helmholtz Inst Funct Marine Biodivers HIFMB, Oldenburg, Germany.;Carl von Ossietzky Univ Oldenburg, Inst Chem & Biol Marine Environm ICBM, Oldenburg, Germany..
    Venail, Patrick
    Univ Ingn & Tecnol UTEC, Ctr Invest & Tecnol Agua CITA, Lima, Peru..
    Adrian, Rita
    Leibniz Inst Freshwater Ecol & Inland Fisheries, Dept Ecosyst Res, Berlin, Germany.;Free Univ Berlin, Dept Chem Pharm & Biol, Berlin, Germany..
    Alfonso, Maria B.
    Univ Nacl Sur UNS, Inst Argentino Oceanog IADO, CONICET, Bahia Blanca, Buenos Aires, Argentina..
    DeGasperi, Curtis L.
    King Cty Water & Land Resources Div, Washington, DC USA..
    de Eyto, Elvira
    Marine Inst Newport Co, Mayo, Ireland..
    Feuchtmayr, Heidrun
    UK Ctr Ecol & Hydrol, Lake Ecosyst Grp, Lancaster, England..
    Gaiser, Evelyn E.
    Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA.;Florida Int Univ, Inst Environm, Miami, FL 33199 USA..
    Girdner, Scott F.
    Crater Lake Natl Pk, Crater Lake, OR USA..
    Graham, Jennifer L.
    US Geol Survey, New York Water Sci Ctr, Troy, NY USA..
    Grossart, Hans-Peter
    Leibniz Inst Freshwater Ecol & Inland Fisheries I, Dept Expt Limnol, Stechlin, Germany.;Potsdam Univ, Inst Biochem & Biol, Potsdam, Germany..
    Hejzlar, Josef
    Czech Acad Sci, Inst Hydrobiol, Biol Ctr, Ceske Budejovice, Czech Republic..
    Jacquet, Stephan
    Univ Savoie Mont Blanc, Inst Natl Rech Agr Alimentat & Environm INRAE, CARRTEL, Thonon Les Bains, France..
    Kirillin, Georgiy
    Leibniz Inst Freshwater Ecol & Inland Fisheries I, Dept Ecohydrol, Berlin, Germany..
    Llames, Maria E.
    Consejo Nacl Invest Cient & Tecn, UNSAM, Inst Tecnol Chascomus INTECH, Lab Ecol Acuat, Buenos Aires, DF, Argentina..
    Matsuzaki, Shin-Ichiro S.
    Ctr Environm Biol & Ecosyst Studies, Inst Environm Studies, Ibaraki, Japan..
    Nodine, Emily R.
    Rollins Coll, Dept Environm Studies, Winter Pk, FL 32789 USA..
    Piccolo, Maria Cintia
    Univ Nacl Sur UNS, Inst Argentino Oceanog IADO, CONICET, Bahia Blanca, Buenos Aires, Argentina..
    Pierson, Don
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Rimmer, Alon
    Israel Oceanog & Limnol Res, Kinneret Limnol Lab, Migdal, Israel..
    Rudstam, Lars G.
    Cornell Univ, Dept Nat Resources, Fernow Hall, Ithaca, NY 14853 USA.;Cornell Univ, Cornell Biol Field Stn, Ithaca, NY USA..
    Sadro, Steven
    Univ Calif Davis, Dept Environm Sci & Policy, Davis, CA 95616 USA..
    Swain, Hilary M.
    Archbold Biol Stn, Venus, FL USA..
    Thackeray, Stephen J.
    UK Ctr Ecol & Hydrol, Lake Ecosyst Grp, Lancaster, England..
    Thiery, Wim
    Vrije Univ Brussel, Dept Hydrol & Hydraul Engn, Brussels, Belgium..
    Verburg, Piet
    Natl Inst Water & Atmospher Res, Hamilton, New Zealand..
    Zohary, Tamar
    Israel Oceanog & Limnol Res, Kinneret Limnol Lab, Migdal, Israel..
    Stockwell, Jason D.
    Univ Vermont, Rubenstein Ecosyst Sci Lab, Burlington, VT 05405 USA..
    The extent and variability of storm-induced temperature changes in lakes measured with long-term and high-frequency data2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 5, s. 1979-1992Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The intensity and frequency of storms are projected to increase in many regions of the world because of climate change. Storms can alter environmental conditions in many ecosystems. In lakes and reservoirs, storms can reduce epilimnetic temperatures from wind-induced mixing with colder hypolimnetic waters, direct precipitation to the lake's surface, and watershed runoff. We analyzed 18 long-term and high-frequency lake datasets from 11 countries to assess the magnitude of wind- vs. rainstorm-induced changes in epilimnetic temperature. We found small day-to-day epilimnetic temperature decreases in response to strong wind and heavy rain during stratified conditions. Day-to-day epilimnetic temperature decreased, on average, by 0.28 degrees C during the strongest windstorms (storm mean daily wind speed among lakes: 6.7 +/- 2.7 m s(-1), 1 SD) and by 0.15 degrees C after the heaviest rainstorms (storm mean daily rainfall: 21.3 +/- 9.0 mm). The largest decreases in epilimnetic temperature were observed >= 2 d after sustained strong wind or heavy rain (top 5(th) percentile of wind and rain events for each lake) in shallow and medium-depth lakes. The smallest decreases occurred in deep lakes. Epilimnetic temperature change from windstorms, but not rainstorms, was negatively correlated with maximum lake depth. However, even the largest storm-induced mean epilimnetic temperature decreases were typically <2 degrees C. Day-to-day temperature change, in the absence of storms, often exceeded storm-induced temperature changes. Because storm-induced temperature changes to lake surface waters were minimal, changes in other limnological variables (e.g., nutrient concentrations or light) from storms may have larger impacts on biological communities than temperature changes.

  • 21. Downing, J. A.
    et al.
    Duarte, C. M.
    Tranvik, Lars J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Striegl, R. G.
    McDowell, W. H.
    Kortelainen, P.
    Caraco, N. F.
    Melack, J. M.
    Middelburg, J. J.
    The global abundance and size distribution of lakes, ponds, and impoundments2006Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 51, nr 5, s. 2388-2397Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies. A global model based on the Pareto distribution shows that the global extent of natural lakes is twice as large as previously known (304 million lakes; 4.2 million km(2) in area) and is dominated in area by millions of water bodies smaller than 1 km(2). Similar analyses of impoundments based on inventories of large, engineered dams show that impounded waters cover approximately 0.26 million km(2). However, construction of low-tech farm impoundments is estimated to be between 0.1% and 6% of farm area worldwide, dependent upon precipitation, and represents > 77,000 km(2) globally, at present. Overall, about 4.6 million km(2) of the earth's continental "land" surface (> 3%) is covered by water. These analyses underscore the importance of explicitly considering lakes, ponds, and impoundments, especially small ones, in global analyses of rates and processes.

  • 22.
    Fernandez-Vidal, Leyden
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Bertilsson, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.
    Peura, Sari
    Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, Sci Life Lab, Uppsala, Sweden.
    Non‐cyanobacterial diazotrophs dominate nitrogen‐fixing communities in permafrost thaw ponds2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr S1, s. 180-193Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is a growing concern about the implications of accelerated thawing of permafrost for regional biogeochemical cycling of carbon and other bioreactive elements. One such element of concern is nitrogen, and in this study, we investigated the diversity and biogeography of potential diazotrophs within a series of thaw ponds representing different ontogenetic stages in pond development. Using metagenomic sequence data from subarctic thaw ponds, we identified an array of nitrogenase genes across the ponds. The iron-only nitrogenase gene (anfH) was positively correlated with sulfate, while there was no correlation with methane despite previous findings that organisms carrying anfH can simultaneously participate in nitrogen fixation and methanogenesis. Sulfate is known to inhibit microbial uptake of molybdate, an element essential for the activity of the nifH (molybdenum-iron) nitrogenase and this may explain the high potential for nitrogen fixation utilizing anfH in sulfate-rich ponds. NifH was particularly abundant in the hypolimnion of the deeper and older ponds, with Deltaproteobacteria and Chlorobi as the putative dominant diazotrophs. In the epilimnetic waters, nifH composition was more variable, with various Gammaproteobacteria as abundant representatives, while cyanobacterial diazotrophs were scarce. Interestingly, nifH gene abundance was significantly positively correlated with in situ methane concentration. Based on genome-resolved metagenomics, we hypothesize that diazotrophs and methanogens engage in syntrophic interactions in anoxic waters, possibly via propionate oxidation or (in Geobacter) by interspecies electron transfer. Our results also suggest that nitrogen fixers may supply bioreactive nitrogen compounds to the thaw pond communities, thereby enhancing growth and activity of methanogens.

  • 23.
    Grasset, Charlotte
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Laboratory of Aquatic Ecology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
    Abril, Gwenaël
    Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Muséum National d'Histoire Naturelle, Paris cedex 05, France; Programa de Geoquímica, Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil.
    Mendonca, Raquel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Laboratory of Aquatic Ecology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
    Roland, Fabio
    Laboratory of Aquatic Ecology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
    Sobek, Sebastian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    The transformation of macrophyte-derived organic matter to methane relates to plant water and nutrient contents2019Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 64, nr 4, s. 1737-1749Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Macrophyte detritus is one of the main sources of organic carbon (OC) in inland waters, and it is potentially available for methane (CH4) production in anoxic bottom waters and sediments. However, the transformation of macrophyte‐derived OC into CH4 has not been studied systematically, thus its extent and relationship with macrophyte characteristics remains uncertain. We performed decomposition experiments of macrophyte detritus from 10 different species at anoxic conditions, in presence and absence of a freshwater sediment, in order to relate the extent and rate of CH4 production to the detritus water content, C/N and C/P ratios. A significant fraction of the macrophyte OC was transformed to CH4 (mean = 7.9%; range = 0–15.0%) during the 59‐d incubation, and the mean total C loss to CO2 and CH4 was 17.3% (range = 1.3–32.7%). The transformation efficiency of macrophyte OC to CH4 was significantly and positively related to the macrophyte water content, and negatively to its C/N and C/P ratios. The presence of sediment increased the transformation efficiency to CH4 from an average of 4.0% (without sediment) to 11.8%, possibly due to physicochemical conditions favorable for CH4 production (low redox potential, buffered pH) or because sediment particles facilitate biofilm formation. The relationship between macrophyte characteristics and CH4 production can be used by future studies to model CH4 emission in systems colonized by macrophytes. Furthermore, this study highlights that the extent to which macrophyte detritus is mixed with sediment also affects CH4 production.

    Fulltekst (pdf)
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  • 24.
    Grasset, Charlotte
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Laboratory of Aquatic Ecology, Department of Biology, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Mendonça, Raquel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Villamor Saucedo, Gabriella
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Bastviken, David
    Department of Thematic Studies – Environmental Change, Linköping University, Linköping, Sweden.
    Roland, Fabio
    Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Sobek, Sebastian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Large but variable methane production in anoxic freshwater sediment upon addition of allochthonous and autochthonous organic matter2018Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 63, nr 4, s. 1488-1501Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An important question in the context of climate change is to understand how CH4 production is regulated in anoxic sediments of lakes and reservoirs. The type of organic carbon (OC) present in lakes is a key factor controlling CH4 production at anoxic conditions, but the studies investigating the methanogenic potential of the main OC types are fragmented. We incubated different types of allochthonous OC (alloOC; terrestrial plant leaves) and autochthonous OC (autoOC; phytoplankton and two aquatic plants species) in an anoxic sediment during 130 d. We tested if (1) the supply of fresh alloOC and autoOC to an anoxic refractory sediment would fuel CH4 production and if (2) autoOC would decompose faster than alloOC. The addition of fresh OC greatly increased CH4 production and the δ13C-CH4 partitioning indicated that CH4 originated exclusively from the fresh OC. The large CH4 production in an anoxic sediment fueled by alloOC is a new finding which indicates that all systems with anoxic conditions and high sedimentation rates have the potential to be CH4 emitters. The autoOC decomposed faster than alloOC, but the total CH4 production was not higher for all autoOC types, one aquatic plant species having values as low as the terrestrial leaves, and the other one having values as high as phytoplankton. Our study is the first to report such variability, suggesting that the extent to which C fixed by aquatic plants is emitted as greenhouse gases or buried as OC in sediment could more generally differ between aquatic vegetation types.

    Fulltekst (pdf)
    fulltext
  • 25.
    Grasset, Charlotte
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Moras, Simone
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Isidorova, Anastasija
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Couture, Raoul-Marie
    Linkhorst, Annika
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Sobek, Sebastian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    An empirical model to predict methane production in inland water sediment from particular organic matter supply and reactivity2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 10, s. 3643-3655Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The highest CH4 production rates can be found in anoxic inland water surface sediments however no model quantifies CH4 production following fresh particular organic matter (POM) deposition on anoxic sediments. This limits our capability of modeling CH4 emissions from inland waters to the atmosphere. To generate such a model, we quantified how the POM supply rate and POM reactivity control CH4 production in anoxic surface sediment, by amending sediment at different frequencies with different quantities of aquatic and terrestrial POM. From the modeled CH4 production, we derived parameters related to the kinetics and the extent of CH4 production. We show that the extent of CH4 production can be well predicted by the quality (i.e., C/N ratio) and the quantity of POM supplied to an anoxic sediment. In particular, within the range of sedimentation rates that can be found in aquatic systems, we show that CH4 production increases linearly with the quantity of phytoplankton-derived and terrestrially derived POM. A high frequency of POM addition, which is a common situation in natural systems, resulted in higher peaks in CH4 production rates. This suggests that relationships derived from earlier incubation experiments that added POM only once, may result in underestimation of sediment CH4 production. Our results quantitatively couple CH4 production in anoxic surface sediment to POM sedimentation flux, and are therefore useful for the further development of mechanistic models of inland water CH4 emission.

    Fulltekst (pdf)
    fulltext
  • 26.
    Gudasz, Cristian
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Bastviken, David
    The Department of Thematic Studies - Water and Environmental Studies Linköping university.
    Premke, Katrin
    Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, and Leibniz Centre for Agricultural Landscape Research (ZALF), Müncheberg, Germany.
    Steger, Kristin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Tranvik, Lars J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Constrained microbial processing of allochthonous organic carbon in boreal lake sediments2012Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 57, nr 1, s. 163-175Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated sediment bacterial metabolism in eight lakes with different inputs of allochthonous and autochthonous organic carbon in south-central Sweden. Sediment bacterial production, mineralization and biomass were measured on a seasonal basis and along a lake depth gradient together with different water and sediment characteristics. Sediment bacterial metabolism was primarily controlled by temperature but also regulated by organic carbon quality/origin. Metabolism was positively correlated to measures of autochthonous influence on the sediment organic carbon, but did not show a similar increase with increasing input of allochthonous organic carbon.  Hence, in contrast to what is currently known for the water column, increasing amounts of terrestrial organic carbon do not result in enhanced sediment bacterial metabolism.  Meio- and macrobenthic invertebrate biomass were at most weakly correlated to bacterial metabolism and biomass, suggesting limited control of sediment bacteria by grazing. We suggest that the bacterial metabolism in boreal lake sediments is constrained by low temperatures and by the recalcitrant nature of the dominant organic carbon, resulting in sediments being an effective sink of organic carbon.

  • 27.
    Hansson, Lars-Anders
    et al.
    Lund Univ, Dept Biol Aquat Ecol, Ecol Bldg, Lund, Sweden..
    Ekvall, Mattias K.
    Lund Univ, Dept Biol Aquat Ecol, Ecol Bldg, Lund, Sweden.;Cty Adm Board Skane Environm & Climate, Malmö, Sweden..
    He, Liang
    Nanchang Univ, Minist Educ, Key Lab Poyang Lake Environm & Resource Utilizat, Nanchang, Jiangxi, Peoples R China..
    Li, Zhongqiang
    Hubei Univ, Fac Resource & Environm, Hubei Key Lab Reg Dev & Environm Response, Wuhan, Peoples R China..
    Svensson, Marie
    Lund Univ, Dept Biol Aquat Ecol, Ecol Bldg, Lund, Sweden..
    Urrutia Cordero, Pablo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Lund Univ, Dept Biol Aquat Ecol, Ecol Bldg, Lund, Sweden..
    Zhang, Huan
    Lund Univ, Dept Biol Aquat Ecol, Ecol Bldg, Lund, Sweden.;Chinese Acad Sci, Inst Hydrobiol, Wuhan, Peoples R China..
    Different climate scenarios alter dominance patterns among aquatic primary producers in temperate systems2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr 10, s. 2328-2336Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In a future climate change perspective, the interactions among different life-forms of primary producers will likely be altered, leading to changes in the relative dominance among macrophytes, filamentous, and planktonic algae. In order to improve the possibilities to forecast future ecosystem services and function, we therefore conducted a long-term mesocosm study where primary producers were exposed to different climate scenarios, including both a mean increase in temperature (4 degrees C) and a similar energy input, but delivered as "heat waves" (fluctuations 0-8 degrees C above ambient). We show that in shallow systems, future climate change scenarios will likely lead to higher total macrophyte biomasses, but also to considerable alterations in the macrophyte community composition. The biomass of filamentous algae (Cladophora) showed no significant difference among treatments, although effect size analyses identified a slight increase at heated conditions. We also show that future climate change will not necessarily lead to more phytoplankton blooms, although a considerable alteration in phytoplankton community composition is to be expected, with a dominance of cyanobacteria and Cryptophytes, whereas Chlorophyceae and diatoms will likely play a less pronounced role than at present. In a broader context, we conclude that the total biomass of macrophytes will likely increase in shallow areas, whereas phytoplankton may not show any strong changes in biomass in a future climate change scenario. Instead, the major changes among primary producers will likely be mirrored in a considerably different species composition than at present.

    Fulltekst (pdf)
    fulltext
  • 28.
    Herrero Ortega, Sonia
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Leibniz Inst Freshwater Ecol & Inland Fisheries I, Dept Expt Limnol, Stechlin, Germany.
    Catalán, Núria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Catalan Inst Water Res ICRA, Girona, Spain.
    Björn, Erik
    Gröntoft, Hannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Hilmarsson, Torfi Geir
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Bertilsson, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Wu, Pianpian
    Bishop, Kevin
    Levanoni, Oded
    Bravo, Andrea Garcia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    High methylmercury formation in ponds fueled by fresh humic and algal derived organic matter2018Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 63, nr S1, s. S44-S53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Neurotoxic methylmercury causes adverse effects to ecosystem viability and human health. Previous studies have revealed that ponding alters natural organic matter (NOM) composition and increase methylmercury concentrations in rivers, especially in the first years after flooding. Here, we investigate the influence of NOM composition (i.e., sources and degradation status) on mercury methylation rate constants in nine boreal beaver ponds of different ages across Sweden.We show that increased methylmercury concentrations in surface waters is a consequence of enhanced mercury methylation in the pond sediments. Moreover, our results reveal that during the first years after the initial flooding, mercury methylation rates are fueled by the amount of fresh humic substances released from the flooded soils and by an increased production of algal-derived NOM triggered by enhanced nutrient availability. Our findings indicate that impoundment-induced changes in NOM composition control mercury methylation processes, causing the raise in MeHg levels in ponds.

    Fulltekst (pdf)
    fulltext
  • 29.
    Irion, Solène
    et al.
    Laboratoire d'Océanologie et de Géosciences, UMR 8187, Université du Littoral Côte d'Opale, CNRS, Université de Lille, Wimereux, France.
    Jardillier, Ludwig
    Unité d'Ecologie, Systématique et Evolution, Université Paris‐Sud, CNRS, AgroParisTech, Université Paris‐Saclay, Orsay Cedex, France.
    Sassenhagen, Ingrid
    Laboratoire d'Océanologie et de Géosciences, UMR 8187, Université du Littoral Côte d'Opale, CNRS, Université de Lille, Wimereux, France.
    Christaki, Urania
    Laboratoire d'Océanologie et de Géosciences, UMR 8187, Université du Littoral Côte d'Opale, CNRS, Université de Lille, Wimereux, France.
    Marked spatiotemporal variations in small phytoplankton structure in contrasted waters of the Southern Ocean (Kerguelen area)2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr 11, s. 2835-2852Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the Southern Ocean, diatom blooms have attracted a lot of attention, while other small nonsilicified phytoplankton groups have been less studied. Here, small phytoplankton (<?20??m, including small diatoms and nonsilicified small phytoplankton) are focused on in two contrasting areas: the productive Kerguelen plateau and its surrounding low productivity waters. To assess the diversity and spatial structuration of phytoplankton, discrete plankton samples (0?300?m layer) of two size fractions (<?20 and 20?100??m) were analyzed with 18S rDNA amplicon sequencing in late summer. Phytoplankton seasonal succession was described using flow cytometry, pigments, and environmental data, from two previous cruises (during the onset and decline of the diatom bloom). In the mixed layer, small nonsilicified phytoplankton represented less than 10% of chlorophyll?a (Chl?a) during the onset and late diatom bloom on the plateau, but they increased on and off the plateau after the bloom (53?70% of Chl?a). Phaeocystis antarctica was relatively abundant at all stations after the bloom, but other small phytoplanktonic groups featured marked differences on and off the plateau. Higher concentrations on the plateau appeared to stimulate the presence of Micromonas, while Pelagophytes were enhanced off the plateau. A diverse assemblage of small diatoms was also promoted off the plateau, where silicate concentration was still high. Interestingly, P. antarctica represented up to 25% of all reads at 300?m depth off the plateau in the larger size fraction suggesting a significant contribution to carbon export through aggregation in low productive waters.

    Fulltekst (pdf)
    fulltext
  • 30.
    Karlsson, Olof Magnus
    et al.
    IVL Swedish Environm Res Inst, Stockholm, Sweden.
    Bryhn, Andreas Christoffer
    Swedish Univ Agr Sci, Dept Aquat Resources, Oregrund, Sweden.
    Håkanson, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Hållén, Joakim
    IVL Swedish Environm Res Inst, Stockholm, Sweden.
    Jonsson, Per
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Stockholm, Sweden.
    Malmaeus, Jan Mikael
    IVL Swedish Environm Res Inst, Stockholm, Sweden.
    Rydin, Emil
    BalticSea2020, Stockholm, Sweden.
    On the role of sedimentological processes controlling phosphorus burial in the coastal zone of the Baltic Sea2019Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 64, nr 4, s. 1828-1831Artikkel i tidsskrift (Annet vitenskapelig)
  • 31.
    Koehler, Birgit
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Broman, Elias
    Linnaeus Univ, Ctr Ecol & Evolut Microbial Model Syst EEMiS, S-39182 Kalmar, Sweden.
    Tranvik, Lars J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Apparent quantum yield of photochemical dissolved organic carbon mineralization in lakes2016Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 61, nr 6, s. 2207-2221Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Up to one tenth of the carbon dioxide (CO2) emissions from inland waters worldwide are directly induced by the photochemical mineralization of dissolved organic matter (DOM). The photochemical production of dissolved inorganic carbon (DIC) per photon absorbed by chromophoric DOM (CDOM) decreases exponentially with increasing irradiance wavelength, and is commonly described by an “apparent quantum yield” (AQY) spectrum. Although an essential model parameter to simulate photochemical mineralization the AQY remains poorly constrained. Here, the AQY of photochemical DIC production for 25 lakes located in boreal, polar, temperate, and tropical areas, including four saline lagoons, was measured. The wavelength-integrated AQY (300–500 nm; mol DIC mol CDOM-absorbed photons−1) ranged from 0.05 in an Antarctic lake to 0.61 in a humic boreal lake, averaging 0.24 ± 0.03 SE. AQY was positively linearly correlated with the absorption coefficient at 420 nm (a420) as a proxy for CDOM content (R2 of 0.64 at 300 nm and 0.26 at 400 nm), with specific UV absorption coefficients as a proxy for DOM aromaticity (R2 of 0.56 at 300 nm and 0.38 at 400 nm), and with the humification index (R2 of 0.41 at 300 nm and 0.42 at 400 nm). Hence, a considerable fraction of the AQY variability was explained by water optical properties in inland waters. The correlation of AQY with a420 opens up the possibility to improve large-scale model estimates of sunlight-induced CO2 emissions from inland waters based on water color information derived by satellite remote sensing.

  • 32.
    Kuhn, McKenzie A.
    et al.
    Univ Alberta, Dept Renewable Resources, Edmonton, AB, Canada.;Univ New Hampshire, Inst Study Earth Oceans & Space, Dept Earth Sci, Durham, NH 03824 USA.;Univ New Hampshire, Inst Study Earth Oceans & Space, Earth Syst Res Ctr, Durham, NH 03824 USA..
    Schmidt, Megan
    Univ Alberta, Dept Renewable Resources, Edmonton, AB, Canada.;Univ Waterloo, Dept Geog & Environm Management, Waterloo, ON, Canada..
    Heffernan, Liam
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Univ Alberta, Dept Renewable Resources, Edmonton, AB, Canada.
    Stührenberg, Jördis
    Univ Munster, Inst Landscape Ecol, Ecohydrol & Biogeochem Grp, Munster, Germany..
    Knorr, Klaus-Holger
    Univ Munster, Inst Landscape Ecol, Ecohydrol & Biogeochem Grp, Munster, Germany..
    Estop-Aragonés, Cristian
    Univ Munster, Inst Landscape Ecol, Ecohydrol & Biogeochem Grp, Munster, Germany..
    Broder, Tanja
    Univ Munster, Inst Landscape Ecol, Ecohydrol & Biogeochem Grp, Munster, Germany..
    Gonzalez Moguel, Regina
    McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ, Canada.;McGill Univ, GEOTOP, Montreal, PQ, Canada..
    Douglas, Peter M. J.
    McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ, Canada.;McGill Univ, GEOTOP, Montreal, PQ, Canada..
    Olefeldt, David
    Univ Alberta, Dept Renewable Resources, Edmonton, AB, Canada..
    High ebullitive, millennial-aged greenhouse gas emissions from thermokarst expansion of peatland lakes in boreal western Canada2023Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 68, nr 2, s. 498-513Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Methane (CH4) and carbon dioxide (CO2) emissions from small peatland lakes may be highly sensitive to climate warming and thermokarst expansion caused by permafrost thaw. We studied effects of thermokarst expansion on ebullitive CH4 and CO2 fluxes and diffusive CH4 fluxes from a peatland thaw lake in boreal western Canada. Ebullitive CH4 fluxes from the thaw edge (236 ± 61 mg CH4 m−2 d−1) were double and quadruple that of the stable lake edge and center, respectively. Modeled diffusive CH4 fluxes did not differ between the thawing and stable edges (~ 50 mg CH4 m−2 d−1) but were double that of the center. Radiocarbon (14C) analysis of CH4 and CO2 bubbles from the thaw edge was older (~ 1211 and 1420 14C yr BP) than from the stable edge and the center (modern to ~ 102 and 50 14C yr BP, respectively). Incubations indicated that deep, old peat sediment was more labile along the thaw edge than in the center. While our study suggested increase CH4 emissions partly derived from millennial-aged carbon along the thaw edge, accounting for these emissions only increased the estimated total lake CH4 emissions by ~ 10%, which is a much smaller contribution than measured from thermokarst lakes in yedoma regions. Our study suggests that it is important to account for landscape history and lake types when studying the processes that govern the sensitivity of lake greenhouse gas emissions to climate change.

  • 33.
    Langenheder, Silke
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution.
    Lindström, Eva S.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution.
    Tranvik, Lars J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution.
    Weak coupling between community composition and functioning of aquatic bacteria2005Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 50, nr 3, s. 957-967Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We performed a batch culture experiment with a factorial design in which sterile water from four lakes and bacterial assemblages (size-fractionated lake water) from the same lakes were set up in all possible combinations. The functional performance (biomass yield, respiration, growth rates, and growth efficiency) of bacterial communities growing in the cultures depended primarily on the type of the medium and to a much lesser extent on the origin of the bacterial assemblage. Functional changes were only partly paralleled by changes in community composition, as indicated by terminal restriction fragment length polymorphism analysis. Similar bacterial communities developed in different cultures as a result of receiving either the same medium or the same inoculum, indicating that bacterial communities are comprised of populations of generalists that can grow under most conditions as well as populations with the life strategy of specialists. However, bacteria originating from a slightly acidic polyhumic lake failed to grow, grew unsteadily, or exhibited an extended lag phase when exposed to media originating from other lakes, indicating that the bacterial community in the polyhumic lake was not able to adapt rapidly to changes in environmental conditions.

  • 34. Leavitt, Peter R.
    et al.
    Fritz, S. C.
    Anderson, N. J.
    Baker, P. A.
    Blenckner, Thorsten
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Bunting, L.
    Catalan, J.
    Conley, D. J.
    Hobbs, W. O.
    Jeppesen, E.
    Korhola, A.
    McGowan, S.
    Ruehland, K.
    Rusak, J. A.
    Simpson, G. L.
    Solovieva, N.
    Werne, J.
    Paleolimnological evidence of the effects on lakes of energy and mass transfer from climate and humans2009Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 54, nr 6, s. 2330-2348Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The premise of this article is that climate effects on lakes can be quantified most effectively by the integration of process-oriented limnological studies with paleolimnological research, particularly when both disciplines operate within a common conceptual framework. To this end, the energy (E)-mass (m) flux framework (Em flux) is developed and applied to selected retrospective studies to demonstrate that climate variability regulates lake structure and function over diverse temporal and spatial scales through four main pathways: rapid direct transfer of E to the lake surface by irradiance, heat, and wind; slow indirect effects of E via changes in terrestrial development and subsequent m subsidies to lakes; direct influx of m as precipitation, particles, and solutes from the atmosphere; and indirect influx of water, suspended particles, and dissolved substances from the catchment. Sedimentary analyses are used to illustrate the unique effects of each pathway on lakes but suggest that interactions among mechanisms are complex and depend on the landscape position of lakes, catchment characteristics, the range of temporal variation of individual pathways, ontogenetic changes in lake basins, and the selective effects of humans on m transfers. In particular, preliminary synthesis suggests that m influx can overwhelm the direct effects of E transfer to lakes, especially when anthropogenic activities alter m subsidies from catchments.

  • 35.
    Lebret, Karen
    et al.
    Lund University.
    Fernandez, Maria Fernandez
    Hagman, Camilla H. C.
    Rengefors, Karin
    Hansson, Lars-Anders
    Grazing resistance allows bloom formation and may explain invasion success of Gonyostomum semen2012Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 57, nr 3, s. 727-734Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The nuisance alga Gonyostomum semen (Raphidophyceae) has expanded in the Nordic countries during the last decades and can dominate lake phytoplankton communities almost completely. A possible explanation to its dominance could be limited grazing by zooplankton. We investigated the potential grazing pressure on G. semen using an experimental approach supported by field data. We determined the grazing rate by cladocerans, calanoid copepods, and Chaoborus larvae to determine which were able to feed on G. semen. Only the large cladoceran Daphnia magna was able to feed successfully on G. semen. The large cell size of G. semen was likely a limiting factor for the filtering apparatus of smaller cladocerans. The copepod Eudiaptomus gracilis did not graze on G. semen, although the mechanism behind this selective feeding is still unknown. In addition to the experimental study, we quantified the zooplankton and phytoplankton communities in 40 lakes to determine the composition and abundance of the zooplankton communities co-occurring with G. semen, suggesting that large cladoceran species were not present in lakes where G. semen occurred. Hence, the growth of G. semen is not significantly controlled by grazing in natural systems, which likely facilitates bloom formation and invasion success of G. semen.

  • 36.
    Lindström, Eva S.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Feng, Xin Mei
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Granéli, Wilhelm
    Kritzberg, Emma S.
    The interplay between bacterial community composition and the environment determining function of inland water bacteria2010Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 55, nr 5, s. 2052-2060Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We hypothesized that habitats differing in water flow regime would differ in bacterial function either because of differences in the local environment, in bacterial community composition (BCC), or in the mechanism shaping BCC (community assembly). In 20 lakes and 17 inlet streams BCC was analyzed by terminal restriction fragment length polymorphism of the gene coding for 16S ribosomal RNA, and bacterial function was estimated as bacterial production rate (BP, measured as leucine incorporation) per content of dissolved organic carbon (DOC) (BP : DOC). BCC in both lakes and streams appeared to be shaped by local environmental forces (i.e., species sorting according to metacommunity theory), but not by massive introduction of cells from the drainage area (mass effect). BP : DOC was lower in streams than in lakes, which appeared to be both because of differences in BCC and environment between lakes and streams, independent of each other. We found no support for an effect of water flow regime in itself (i.e., cell dispersal rate) causing the lower functionality of the streams. In streams, BP : DOC was correlated to both BCC and environment, independent of each other, while in lakes function could not be explained by either BCC or environment. The greater environmental variability among our streams than among our lakes may be the cause for the stronger BCC-function coupling in our streams, since smaller environmental variation among our lakes would allow a greater functional redundancy.

  • 37.
    Linkhorst, Annika
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Hiller, Carolin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    DelSontro, Tonya
    Aquatic Physics Group, Department F.-A. Forel for Environmental and Aquatic Sciences, Faculty of Science, University of Geneva, Geneva, Switzerland.
    Azevedo, Guilherme M.
    Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Barros, Nathan
    Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Mendonça, Raquel
    Department of Biology, Institute of Biological Sciences, Federal University of Juiz de Fora, Juiz de Fora, Brazil.
    Sobek, Sebastian
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Comparing methane ebullition variability across space and time in a Brazilian reservoir2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr 7, s. 1623-1634Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The potent greenhouse gas methane (CH4) is readily emitted from tropical reservoirs, often via ebullition (bubbles). This highly stochastic emission pathway varies in space and time, however, hampering efforts to accurately assess total CH4 emissions from water bodies. We systematically studied both the spatial and temporal scales of ebullition variability in a river inflow bay of a tropical Brazilian reservoir. We conducted multiple highly resolved spatial surveys of CH4 ebullition using a hydroacoustic approach supplemented with bubble traps over a 12‐month and a 2‐week timescale to evaluate which scale of variation was more important. To quantify the spatial and temporal variability of CH4 ebullition, we used the quartile coefficients of dispersion at each point in space and time and compared their frequency distributions across the various temporal and spatial scales. We found that CH4 ebullition varied more temporally than spatially and that the intra‐annual variability was stronger than daily variability within 2 weeks. We also found that CH4 ebullition was positively related to water temperature increase and pressure decrease, but no consistent relationship with water column depth or sediment characteristics was found, further highlighting that temporal drivers of emissions were stronger than spatial drivers. Annual estimates of CH4 ebullition from our study area may vary by 75–174% if ebullition is not resolved in time and space, but at a minimum we recommend conducting spatially resolved measurements at least once during each major hydrologic season in tropical regions (i.e., in dry and rainy season when water levels are falling and rising, respectively).

    Fulltekst (pdf)
    fulltext
  • 38.
    Logue, Jürg Brendan
    et al.
    Swiss Federal Institute of Aquatic Science and Technology (EAWAG).
    Robinson, Christopher T.
    Swiss Federal Institute of Aquatic Science and Technology (EAWAG).
    Meier, Christoph
    Swiss Federal Institute of Aquatic Science and Technology (EAWAG).
    van der Meer, Jan Roelof
    Swiss Federal Institute of Aquatic Science and Technology (EAWAG).
    Relationship between sediment organic matter, bacteria composition, and the ecosystem metabolism of alpine streams2004Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 49, nr 6, s. 2001-2010Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We tested whether sediment bacteria abundance (4´,6-diamidino-2-phenylindole–stained cell counts) were related to sediment organic content (ash-free dry mass [AFDM]) in 11 nonforested streams of three different Alpine catchments during summer 2003. We used terminal restriction fragment–length polymorphism (T-RLFP, a moleculargenetic technique) to test for seasonal and spatial differences in bacterial composition in these same streams. We then related the above parameters, in conjunction with periphyton biomass and hyporheic respiration, to whole stream estimates of gross primary production (GPP) and ecosystem respiration (ER) in a glacial and nonglacial stream, representing environmental extremes, in one of the catchments. The percentage of organic matter of sediments was 4–14% (0.01–0.04 g AFDM ml sediment-1), and counts of bacteria cells per millimeter of sediment averaged 2x10^6–4x10^6. Bacteria counts correlated with sediment AFDM only for streams in the catchment with highest sediment AFDM levels. Bacteria composition (based on the presence and absence of terminal restriction fragments from T-RFLP analysis) changed seasonally in the different streams and differed between glacial- and groundwater-fed streams. In the one catchment, hyporheic respiration averaged 0.0004 and 0.0003 g O2 h-1 kg sediment-1 and was positively correlated with AFDM (r2=0.23). Ecosystem metabolism displayed a strong seasonality, with GPP averaging 4.5 and 8.4 and ER averaging 5.4 and 9.9 g O2 m-2 d-1 for the two sites, respectively, thus indicating a predominance of heterotrophy (P:R<1) in these high-elevation, open-canopied systems. Bacteria play a strong role in the trophic dynamics of alpine streams.

  • 39.
    MacIntyre, Sally
    et al.
    Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA.;Univ Calif Santa Barbara, Marine Sci Inst, Santa Barbara, CA 93106 USA.;Univ Calif Santa Barbara, Earth Res Inst, Santa Barbara, CA 93106 USA..
    Bastviken, David
    Linköping Univ, Dept Themat Studies Environm Change, Linköping, Sweden..
    Arneborg, Lars
    Swedish Meteorol & Hydrol Inst, Vastra Frolunda, Sweden..
    Crowe, Adam T.
    Univ Calif Santa Barbara, Earth Res Inst, Santa Barbara, CA 93106 USA..
    Karlsson, Jan
    Umeå Univ, Dept Ecol & Environm Sci, Umeå, Sweden..
    Andersson, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära. Mid Sweden Univ, Dept Ecotechnol & Sustainable Bldg Engn, Östersund, Sweden..
    Gålfalk, Magnus
    Linköping Univ, Dept Themat Studies Environm Change, Linköping, Sweden..
    Rutgersson, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Podgrajsek, Eva
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Melack, John M.
    Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA.;Univ Calif Santa Barbara, Earth Res Inst, Santa Barbara, CA 93106 USA..
    Turbulence in a small boreal lake: Consequences for air-water gas exchange2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 3, s. 827-854Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The hydrodynamics within small boreal lakes have rarely been studied, yet knowing whether turbulence at the air-water interface and in the water column scales with metrics developed elsewhere is essential for computing metabolism and fluxes of climate-forcing trace gases. We instrumented a humic, 4.7 ha, boreal lake with two meteorological stations, three thermistor arrays, an infrared (IR) camera to quantify surface divergence, obtained turbulence as dissipation rate of turbulent kinetic energy (epsilon) using an acoustic Doppler velocimeter and a temperature-gradient microstructure profiler, and conducted chamber measurements for short periods to obtain fluxes and gas transfer velocities (k). Near-surface epsilon varied from 10(-8) to 10(-6) m(2) s(-3) for the 0-4 m s(-1) winds and followed predictions from Monin-Obukhov similarity theory. The coefficient of eddy diffusivity in the mixed layer was up to 10(-3) m(2) s(-1) on the windiest afternoons, an order of magnitude less other afternoons, and near molecular at deeper depths. The upper thermocline upwelled when Lake numbers (L-N) dropped below four facilitating vertical and horizontal exchange. k computed from a surface renewal model using epsilon agreed with values from chambers and surface divergence and increased linearly with wind speed. Diurnal thermoclines formed on sunny days when winds were < 3 m s(-1), a condition that can lead to elevated near-surface epsilon and k. Results extend scaling approaches developed in the laboratory and for larger water bodies, illustrate turbulence and k are greater than expected in small wind-sheltered lakes, and provide new equations to quantify fluxes.

    Fulltekst (pdf)
    fulltext
  • 40.
    Mesman, Jorrit P.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Department F.-A. Forel for Environmental and Aquatic Sciences, Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland University of Geneva, Group of Applied Physics and Institute for Environmental Sciences, Geneva, Switzerland.
    Ayala, Ana I.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. University of Geneva, Group of Applied Physics and Institute for Environmental Sciences, Geneva, Switzerland.
    Goyette, Stéphane
    Kasparian, Jérôme
    Marcé, Rafael
    Markensten, Hampus
    Stelzer, Julio A. A.
    Thayne, Michael W.
    Thomas, Mridul K.
    Pierson, Don C.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Ibelings, Bas W.
    Drivers of phytoplankton responses to summer wind events in a stratified lake: a modelling study2022Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 67, nr 4, s. 856-873Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Extreme wind events affect lake phytoplankton amongst others by deepening the mixed layer and increasing internal nutrient loading. Both increases and decreases of phytoplankton biomass after storms have been observed, but the precise mechanisms driving these responses remain poorly understood or quantified. In this study, we coupled a one-dimensional physical model to a biogeochemical model to investigate the factors regulating short-term phytoplankton responses to summer storms, now and under expected warmer future conditions. We simulated physical, chemical and biological dynamics in Lake Erken, Sweden, and found that wind storms could increase or decrease the phytoplankton concentration one week after the storm, depending on antecedent lake physical and chemical conditions. Storms had little effect on phytoplankton biomass if the mixed layer was deep prior to storm exposure. Higher incoming shortwave radiation and hypolimnetic nutrient concentration boosted growth, whereas higher surface water temperatures decreased phytoplankton concentration after storms. Medium-intensity wind speeds resulted in more phytoplankton biomass after storms than high-intensity wind. Simulations under a future climate scenario did not show marked differences in the way wind affects phytoplankton growth following storms. Our study shows that storm impacts on lake phytoplankton are complex and likely to vary as a function of local environmental conditions.

    Fulltekst (pdf)
    fulltext
  • 41.
    Naddafi, Rahmat
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Pettersson, Kurt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Eklöv, Peter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Effects of the zebra mussel, an exotic freshwater species, on seston stoichiometry2008Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 53, nr 5, s. 1973-1987Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We examined the effect of the zebra mussel, Dreissena polymorpha, an exotic species, on seston stoichiometry by conducting laboratory experiments in which we varied nutrient composition of seston and mussels over time. Zebra mussels altered the stoichiometry of seston through removal of particulate organic nutrients and changed the stoichiometry of the dissolved nutrient pool through nutrient excretion. Grazers had stronger effects on carbon : phosphorus (C : P) and nitrogen (N) : P ratios than on the C:N ratio of seston. Elemental residence time in tissue and high mass-specific nutrient excretion by small mussels caused small mussels to be more efficient nutrient recyclers than larger mussels. Zebra mussels reduced P availability through enhancing C: P and N: P molar ratios of seston during the period extending from June to August, when P was limited in the lake, and increased the C:N molar ratio of seston in June, when N was at the minimum level in the lake. C: P and N: P molar ratios for zebra mussel tissue were higher in August and somewhat in September than in all other months. N was retained more efficiently than P in Dreissena tissue. Nutrient mass-specific uptake rate was higher than excretion rate by zebra mussels.

  • 42.
    Nie, Xiang-Ping
    et al.
    Department of Ecology, Jian University, Guangzhou, China.
    Zie, Jenny
    Department of Systems Ecology, Stockholm University.
    Häubner, Norbert
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Ekologisk botanik.
    Tallmark, Bo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Snoeijs, Pauli
    Department of Systems Ecology, Stokcholm University.
    Prey diversity and prey stomach contents affect astaxanthin levels in piscivorous fishInngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We analyzed astaxanthin concentrations and the composition of geometrical (E/Z) astaxanthin isomers in 631 tissue samples from the four chief fish species in the pelagic zone of the brackish Baltic Sea. Salmon and herring showed signs of astaxanthin deficiency, but cod and sprat did not. The isomers were distributed selectively in fish tissues, with highest proportions of all-E-astaxanthin in salmon gonads (71%) and lowest in herring gonads (19%). We discovered that the clupeids are no ideal prey for salmon and cod with respect to their high whole-body concentrations of astaxanthin Z-isomers, which have low bioavailability for salmon and cod. The salmon in the Baltic Sea is entirely dependent on herring and sprat for food intake while cod feeds on a more diverse diet, including crustaceans. This explains the normal low astaxanthin levels in the salmon in the Baltic Sea. Observed decreases in astaxanthin levels in the Baltic salmon during the last 50 years, which are related to a reproductional disturbance (M74 syndrome), can be explained by the here described poor quality of herring as astaxanthin source in combination with recorded changes in the feeding ecology of the Baltic salmon with less sprat and more herring in the diet today. Herring is inferior to sprat as astaxanthin source, especially in autumn when a salmon or cod obtains four times more bioavailable all-E-astaxanthin (by weight) from sprat than from herring. The Baltic herring is starving more than the sprat as a result of competition between the clupeids though fishing mortality and recruitment problems of the cod, their major predator during the last decades. Therefore, less crustacean astaxanthin (mainly all-E) is transferred directly to piscivorous fish from herring stomachs than from sprat stomachs.

  • 43. Nie, Xiang-Ping
    et al.
    Zie, Jenny
    Häubner, Norbert
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Tallmark, Bo
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Snoeijs, Pauline
    Why Baltic herring and sprat are weak conduits for astaxanthin from zooplankton to piscivorous fish2011Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, nr 3, s. 1155-1167Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Atlantic salmon living in the brackish Baltic Sea have lower muscle pigmentation than populations elsewhere. The pigment in question is the antioxidant and vitamin A precursor astaxanthin, which is synthesized by crustaceans from algal carotenoids. Baltic salmon feed nearly exclusively on the clupeids sprat and herring. To evaluate astaxanthin availability to salmon we assessed astaxanthin levels and isomeric composition in their prey fish. We also analyzed astaxanthin dynamics in the dominant piscivorous fish in the Baltic Sea, the Atlantic cod. The geometrical E-(trans-) and Z-(cis-) isomers were distributed selectively in fish tissues, with highest E : Z ratios in salmon gonads (82 : 18) and lowest in herring gonads (24 : 76). Sprat and herring are not ideal prey with respect to their high whole-body concentrations of Z-isomers, which have low bioavailability for salmon and cod. These Z-isomers predominantly accumulate in the clupeid gonads. A crucial mechanism for the transport of astaxanthin from clupeids to piscivores is the direct transfer of crustacean astaxanthin (mainly all-E) from the clupeid stomachs. Low stomach astaxanthin content in clupeids decreases total astaxanthin transfer to higher trophic levels. In autumn, herring stomachs (including contents) had 12.5 times lower astaxanthin concentrations than sprat stomachs, and herring had 2.8 times less whole-body all-E-astaxanthin (by weight) than sprat. These results confirm recent reports of starvation in the Baltic herring, which may further decrease astaxanthin levels in the Baltic salmon. Cod did not have lower astaxanthin levels than their Atlantic counterpart, which may be attributed to their lower need for astaxanthin and higher food diversity.

  • 44.
    Niklasdotter Scherrer, Kim Josefin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper. Univ Ctr Svalbard, Dept Arctic Biol, Longyearbyen, Norway; Univ Autonoma Barcelona, Inst Ciencia & Tecnol Ambientals, Cerdanyola Del Valles, Spain.
    Kortsch, S.
    UiT Arctic Univ Norway, Fac Biosci Fisheries & Econ, Tromsø, Norway.
    Varpe, Ø.
    Univ Ctr Svalbard, Dept Arctic Biol, Longyearbyen, Norway; Akvaplan Niva, Fram Ctr, Tromsø, Norway.
    Weyhenmeyer, Gesa A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Gulliksen, B.
    UiT Arctic Univ Norway, Fac Biosci Fisheries & Econ, Tromsø, Norway.
    Primicerio, R.
    UiT Arctic Univ Norway, Fac Biosci Fisheries & Econ, Tromsø, Norway.
    Mechanistic model identifies increasing light availability due to sea ice reductions as cause for increasing macroalgae cover in the Arctic2019Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 64, nr 1, s. 330-341Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the Arctic, rising seawater temperatures and increasing underwater light caused by reductions in sea ice cover are expected to change the structure of arctic marine communities. Substantial, sometimes sudden, increases in macroalgal productivity and biomass have already been observed in arctic rocky bottom communities. These macroalgal responses have been attributed to increasing temperature and light, but the relative importance of the suggested drivers of change has not yet been assessed. In this study, we used a mechanistic competition model to unravel the effects of temperature and light on benthic community structure and algae dominance, focusing on key algae species: red calcareous algae and macroalgal fronds. We find that light is the primary driver of increases in macroalgal coverage, whereas increased seawater temperature plays a secondary role. Shifts leading to macroalgae dominated communities may be mediated by competitive interactions, and are likely due to three light-related processes: earlier sea ice break-out at high latitudes can result in an exponential increase in the cumulative amount of light that enters the water column during a year; threshold effect in light requirements for algal growth; and light requirements of calcareous algae being substantially lower than those of macroalgae. With continued warming, our modeling results suggest that reduced sea ice coverage and increased light availability will favor dominance of macroalgae, which due to their key ecological role are expected to alter the structure and functioning of arctic rocky bottom ecosystems.

    Fulltekst (pdf)
    FULLTEXT01
  • 45.
    Nydahl, Anna
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Wallin, Marcus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Tranvik, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Hiller, Carolin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Attermeyer, Katrin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Garrison, Julie A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Chaguaceda, Fernando
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Scharnweber, Kristin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Weyhenmeyer, Gesa A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Colored organic matter increases CO2 in meso-eutrophic lake water through altered light climate and acidity2019Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 64, nr 2, s. 744-756Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many surface waters across the boreal region are browning due to increased concentrations of colored allochthonous dissolved organic carbon (DOC). Browning may stimulate heterotrophic metabolism, may have a shading effect constraining primary production, and may acidify the water leading to decreased pH with a subsequent shift in the carbonate system. All these effects are expected to result in increased lake water carbon dioxide (CO2) concentrations. We tested here these expectations by assessing the effects of both altered allochthonous DOC input and light conditions through shading on lake water CO2 concentrations. We used two mesocosm experiments with water from the meso‐eutrophic Lake Erken, Sweden, to determine the relative importance of bacterial activities, primary production, and shifts in the carbonate system on CO2 concentrations. We found that DOC addition and shading resulted in a significant increase in partial pressure of CO2 (pCO2) in all mesocosms. Surprisingly, there was no relationship between bacterial activities and pCO2. Instead the experimental reduction of light by DOC and/or shading decreased the photosynthesis to respiration ratio leading to increased pCO2. Another driving force behind the observed pCO2 increase was a significant decrease in pH, caused by a decline in photosynthesis and the input of acidic DOC. Considering that colored allochthonous DOC may increase in a warmer and wetter climate, our results could also apply for whole lake ecosystems and pCO2 may increase in many lakes through a reduction in the rate of photosynthesis and decreased pH.

    Fulltekst (pdf)
    fulltext
  • 46.
    Patriarca, Claudia
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Sedano Núñez, Vicente T.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Garcia, Sarahi L
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Department of Ecology, Environment, and Plant Sciences, Science for Life Laboratory, Stockholm University, Stockholm, Sweden.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bertilsson, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Sjöberg, Per J. R.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Tranvik, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Hawkes, Jeffrey A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Character and environmental lability of cyanobacteria-derived dissolved organic matter2021Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 66, nr 2, s. 496-509Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Autotrophic dissolved organic matter (DOM) is central to the carbon biogeochemistry of aquatic systems, and the full complexity of autotrophic DOM has not been extensively studied, particularly by high‐resolution mass spectrometry (HRMS). Terrestrial DOM tends to dominate HRMS studies in freshwaters due to the propensity of such compounds to ionize by negative mode electrospray, and possibly also because ionizable DOM produced by autotrophy is decreased to low steady‐state concentrations by heterotrophic bacteria. In this study, we investigated the character of DOM produced by the widespread cyanobacteria Microcystis aeruginosa using high‐pressure liquid chromatography—electrospray ionization—high‐resolution mass spectrometry. M. aeruginosa produced thousands of detectable compounds in axenic culture. These compounds were chromatographically resolved and the majority were assigned to aliphatic formulas with a broad polarity range. We found that the DOM produced by M. aeruginosa was highly susceptible to removal by heterotrophic freshwater bacteria, supporting the hypothesis that this autotroph‐derived organic material is highly labile and accordingly only seen at low concentrations in natural settings.

    Fulltekst (pdf)
    fulltext
  • 47.
    Peura, Sari
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Swedish Univ Agr Sci, Dept Forest Mycol & Plant Pathol, Sci Life Lab, Uppsala, Sweden.
    Wauthy, Maxime
    Univ Quebec Chicoutimi, Dept Sci Fondamentales, Chicoutimi, PQ, Canada;Univ Laval, CEN, Quebec City, PQ, Canada.
    Simone, Domenico
    Swedish Univ Agr Sci, Dept Plant Biol, Uppsala, Sweden;Swedish Univ Agr Sci, SLU Bioinformat Infrastruct, Uppsala, Sweden.
    Eiler, Alexander
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Univ Oslo, Ctr Biogeochem Anthropocene, Dept Biosci, Sect Aquat Biol & Toxicol, Oslo, Norway.
    Einarsdóttir, Karólina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Rautio, Milla
    Univ Quebec Chicoutimi, Dept Sci Fondamentales, Chicoutimi, PQ, Canada;Univ Laval, CEN, Quebec City, PQ, Canada;Univ Montreal, Grp Interuniv Res Limnol & Aquat Environm GRIL, Montreal, PQ, Canada.
    Bertilsson, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.
    Ontogenic succession of thermokarst thaw ponds is linked to dissolved organic matter quality and microbial degradation potential2020Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 65, nr SI, s. S248-S263Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Warming climate is thawing the permafrost in arctic and subarctic regions, leading to formation of thermokarst ponds. During the formation and geomorphological succession of these ponds, carbon that has been trapped in frozen soils for thousands of years is hydrologically mobilized and returned to the active carbon cycle. We sampled 12 thermokarst ponds representing three different stages of pond succession to study the potential of microbial communities to metabolize the organic carbon in the water. We investigated the quality of the dissolved organic carbon (DOC) in the water column based on the spectrophotometric and fluorometric properties of the chromophoric dissolved organic matter combined with parallel factor analysis and the potential of the microbial community for degrading these carbon compounds based on genetic markers related to carbon degradation. Our analysis showed a clear difference in the DOC quality across the different developmental stages. In the younger ponds, organic matter quality suggested that it was originating from the degrading permafrost and in the metagenomes collected from these ponds, the normalized abundance of genes related to degradation of carbon compounds was higher. There was also a shift in the degradation potential in the water column of the ponds, with higher potential for organic matter degradation in deeper, anoxic layers. In conclusion, our results show that the DOC quality and the genetic potential of the microbial community for carbon cycling change across the pond ontogeny, suggesting a capacity of the microbial communities to adapt to changing environmental conditions.

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  • 48.
    Podgrajsek, Eva
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Sahlée, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Bastviken, David
    Linkoping Univ, Dept Themat Studies Environm Change, Linkoping, Sweden.
    Natchimuthu, Siva
    Linkoping Univ, Dept Themat Studies Environm Change, Linkoping, Sweden.
    Kljun, Natascha
    Swansea Univ, Dept Geog, Singleton Pk, Swansea, W Glam, Wales.
    Chmiel, Hannah
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Klemedtsson, Leif
    Univ Gothenburg, Dept Earth Sci, Gothenburg, Sweden.
    Rutgersson, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Methane fluxes from a small boreal lake measured with the eddy covariance method2016Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 61, s. S41-S50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fluxes of methane, CH4, were measured with the eddy covariance (EC) method at a small boreal lake in Sweden. The mean CH4 flux during the growing season of 2013 was 20.1 nmol m22 s 21 and the median flux was 16 nmol m22 s 21 (corresponding to 1.7 mmol m22 d21 and 1.4 mmol m22 d21 ). Monthly mean values of CH4 flux measured with the EC method were compared with fluxes measured with floating chambers (FC) and were in average 62% higher over the whole study period. The difference was greatest in April partly because EC, but not FC, accounted for fluxes due to ice melt and a subsequent lake mixing event. A footprint analysis revealed that the EC footprint included primarily the shallow side of the lake with a major inlet. This inlet harbors emergent macrophytes that can mediate high CH4 fluxes. The difference between measured EC and FC fluxes can hence be explained by different footprint areas, where the EC system “sees” the part of the lake presumably releasing higher amounts of CH4. EC also provides more frequent measurements than FC and hence more likely captures ebullition events. This study shows that small lakes have CH4 fluxes that are highly variable in time and space. Based on our findings we suggest to measure CH4 fluxes from lakes as continuously as possible and to aim for covering as much of the lakes surface as possible, independently of the selected measuring technique.

  • 49.
    Ray, Nicholas E. E.
    et al.
    Cornell Univ, Dept Ecol & Evolutionary Biol, Ithaca, NY 14850 USA..
    Holgerson, Meredith A. A.
    Cornell Univ, Dept Ecol & Evolutionary Biol, Ithaca, NY 14850 USA..
    Andersen, Mikkel Rene
    Dundalk Inst Technol, Ctr Freshwater & Environm Studies, Dundalk, Ireland..
    Bikse, Janis
    Univ Latvia, Fac Geog & Earth Sci, Riga, Latvia..
    Bortolotti, Lauren E. E.
    Ducks Unlimited Canada, Inst Wetland & Waterfowl Res, Stonewall, MB, Canada..
    Futter, Martyn
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden..
    Kokorite, Ilga
    Univ Latvia, Inst Biol, Riga, Latvia..
    Law, Alan
    Univ Stirling, Biol & Environm Sci, Stirling, Scotland..
    McDonald, Cory
    Michigan Technol Univ, Dept Civil Environm & Geospatial Engn, Houghton, MI USA..
    Mesman, Jorrit P.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi. Univ Geneva, Dept FA Forel Environm & Aquat Sci, Geneva, Switzerland.
    Peacock, Mike
    Swedish Univ Agr Sci, Dept Aquat Sci & Assessment, Uppsala, Sweden.;Univ Liverpool, Sch Environm Sci, Dept Geog & Planning, Liverpool, England..
    Richardson, David C. C.
    SUNY Coll New Paltz, Biol Dept, New Paltz, NY USA..
    Arsenault, Julien
    Univ Montreal, Dept Geog, Grp Rech Interuniv Limnol GRIL, Montreal, PQ, Canada..
    Bansal, Sheel
    US Geol Survey, Northern Prairie Wildlife Res Ctr, Jamestown, ND USA..
    Cawley, Kaelin
    Battelle Mem Inst, NEON Project, Boulder, CO USA..
    Kuhn, McKenzie
    Univ New Hampshire, Dept Earth Sci, Durham, NH USA..
    Shahabinia, Amir Reza
    Univ New Hampshire, Inst Study Earth Ocean & Space, Earth Syst Res Ctr, Durham, NH USA.;Univ Quebec Montreal, Dept Sci Biol, Grp Rech Interuniv Limnol GRIL, Montreal, PQ, Canada..
    Smufer, Facundo
    Univ New Hampshire, Inst Study Earth Ocean & Space, Earth Syst Res Ctr, Durham, NH USA.;Univ Quebec Montreal, Dept Sci Biol, Grp Rech Interuniv Limnol GRIL, Montreal, PQ, Canada..
    Spatial and temporal variability in summertime dissolved carbon dioxide and methane in temperate ponds and shallow lakes2023Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 68, nr 7, s. 1530-1545Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Small waterbodies have potentially high greenhouse gas emissions relative to their small footprint on the landscape, although there is high uncertainty in model estimates. Scaling their carbon dioxide (CO2) and methane (CH4) exchange with the atmosphere remains challenging due to an incomplete understanding and characterization of spatial and temporal variability in CO2 and CH4. Here, we measured partial pressures of CO2 (pCO2) and CH4 (pCH4) across 30 ponds and shallow lakes during summer in temperate regions of Europe and North America. We sampled each waterbody in three locations at three times during the growing season, and tested which physical, chemical, and biological characteristics related to the means and variability of pCO2 and pCH4 in space and time. Summer means of pCO2 and pCH4 were inversely related to waterbody size and positively related to floating vegetative cover; pCO2 was also positively related to dissolved phosphorus. Temporal variability in partial pressure in both gases weas greater than spatial variability. Although sampling on a single date was likely to misestimate mean seasonal pCO2 by up to 26%, mean seasonal pCH4 could be misestimated by up to 64.5%. Shallower systems displayed the most temporal variability in pCH4 and waterbodies with more vegetation cover had lower temporal variability. Inland waters remain one of the most uncertain components of the global carbon budget; understanding spatial and temporal variability will ultimately help us to constrain our estimates and inform research priorities.

  • 50.
    Richardson, David C.
    et al.
    SUNY Coll New Paltz, Biol Dept, New Paltz, NY 12561 USA..
    Filazzola, Alessandro
    Apex Resource Management Solut, Ottawa, ON, Canada.;York Univ, Dept Biol, Toronto, ON, Canada..
    Woolway, R. Iestyn
    Bangor Univ, Sch Ocean Sci, Anglesey, Wales..
    Imrit, M. Arshad
    York Univ, Dept Biol, Toronto, ON, Canada..
    Bouffard, Damien
    Swiss Fed Inst Aquat Sci & Technol, Dept Surface Waters Res & Management, Eawag, Kastanienbaum, Switzerland.;Univ Lausanne, Inst Earth Surface Dynam, Fac Geosci & Environm, Lausanne, Switzerland..
    Weyhenmeyer, Gesa A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Magnuson, John
    Univ Wisconsin Madison, Ctr Limnol, Madison, WI USA..
    Sharma, Sapna
    York Univ, Dept Biol, Toronto, ON, Canada..
    Nonlinear responses in interannual variability of lake ice to climate change2024Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 69, nr 4, s. 789-801Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change is contributing to rapid changes in lake ice cover across the Northern Hemisphere, thereby impacting local communities and ecosystems. Using lake ice cover time-series spanning over 87 yr for 43 lakes across the Northern Hemisphere, we found that the interannual variability in ice duration, measured as standard deviation, significantly increased in only half of our studied lakes. We observed that the interannual variability in ice duration peaked when lakes were, on average, covered by ice for about 1 month, while both longer and shorter long-term mean ice cover duration resulted in lower interannual variability in ice duration. These results demonstrate that the ice cover duration can become so short that the interannual variability rapidly declines. The interannual variability in ice duration showed a strong dependency on global temperature anomalies and teleconnections, such as the North Atlantic Oscillation and El Nino-Southern Oscillation. We conclude that many lakes across the Northern Hemisphere will experience a decline in interannual ice cover variability and shift to open water during the winter under a continued global warming trend which will affect lake biological, cultural, and economic processes.

12 1 - 50 of 73
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