Viser treff 501-520 av 1521

    • Cannibalism and protective behavior of eggs in Arctic charr (Salvelinus alpinus) 

      Frye, Marilena; Egeland, Torvald Blikra; Nordeide, Jarle Tryti; Folstad, Ivar (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-28)
      From video recordings of spawning events, we quantified protective and cannibalistic behavior of Arctic charr occurring immediately after spawning. The number of fish cannibalizing on stray eggs was examined regarding (a) whether more than one male shed milt during the spawning event, that is, whether sperm competition occurred, (b) whether the sperm competition included few or many males, that is, ...
    • Microbial carbon use and associated changes in microbial community structure in high-Arctic tundra soils under elevated temperature 

      Frossard, Aline; De Maeyer, Lotte; Adamczyk, Magdalene; Svenning, Mette Marianne; Verleyen, Elie; Frey, Beat (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-08)
      In the high-Arctic, increased temperature results in permafrost thawing and increased primary production. This fresh plant-derived material is predicted to prime microbial consortia for degradation of the organic matter stored in tundra soils. However, the effects of warming and plant input on the microbial community structure is hardly known. We assessed the use of glycine, a readily available C ...
    • Influence of reproductive output on divorce rates in polar seabirds 

      Mercier, Guillaume; Yoccoz, Nigel; Descamps, Sébastien (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-15)
      The high occurrence of social monogamy in birds has led to questions about partner fidelity, or the perennial nature of monogamy from one breeding season to another. Despite the evolutionary advantages of partner fidelity, divorce occurs among 95% of bird species. We aimed to describe patterns of divorce and partner fidelity in five seabird species breeding in Arctic and Antarctic regions and ...
    • How microbial food web interactions shape the arctic ocean bacterial community revealed by size fractionation experiments 

      Müller, Oliver; Seuthe, Lena; Pree, Bernadette; Bratbak, Gunnar; Larsen, Aud; Paulsen, Maria Lund (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-17)
      In the Arctic, seasonal changes are substantial, and as a result, the marine bacterial community composition and functions differ greatly between the dark winter and light-intensive summer. While light availability is, overall, the external driver of the seasonal changes, several internal biological interactions structure the bacterial community during shorter timescales. These include specific ...
    • Disturbance mapping in arctic tundra improved by a planning workflow for drone studies: Advancing tools for future ecosystem monitoring 

      Eischeid, Isabell; Soininen, Eeva M; Assmann, Jakob J.; Ims, Rolf Anker; Madsen, Jesper; Pedersen, Åshild Ø.; Pirotti, Francesco; Yoccoz, Nigel; Ravolainen, Virve T. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-06)
      The Arctic is under great pressure due to climate change. Drones are increasingly used as a tool in ecology and may be especially valuable in rapidly changing and remote landscapes, as can be found in the Arctic. For effective applications of drones, decisions of both ecological and technical character are needed. Here, we provide our method planning workflow for generating ground-cover maps with ...
    • CASCADE-The Circum-Arctic Sediment CArbon DatabasE 

      Martens, Jannik; Romankevich, Evgeny; Semiletov, Igor; Wild, Birgit; Van Dongen, Bart; Vonk, Jorien; Tesi, Tommaso; Shakhova, Natalia; Dudarev, Oleg V.; Kosmach, Denis; Vetrov, Alexander; Lobkovsky, Leopold; Belyaev, Nikolay; Macdonald, Robie W.; Pieńkowski, Anna J.; Eglinton, Timothy I.; Haghipour, Negar; Dahle, Salve; Carroll, Michael L.; Åström, Emmelie; Grebmeier, Jacqueline M.; Cooper, Lee W.; Possnert, Göran; Gustafsson, Örjan (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-08)
      Biogeochemical cycling in the semi-enclosed Arctic Ocean is strongly influenced by land–ocean transport of carbon and other elements and is vulnerable to environmental and climate changes. Sediments of the Arctic Ocean are an important part of biogeochemical cycling in the Arctic and provide the opportunity to study present and historical input and the fate of organic matter (e.g., through permafrost ...
    • Isoscape Models of the Southern Ocean: Predicting Spatial and Temporal Variability in Carbon and Nitrogen Isotope Compositions of Particulate Organic Matter 

      Glew, Katie St John; Espinasse, Boris; Hunt, Brian P. V.; Pakhomov, Evgeny A.; Bury, Sarah J.; Pinkerton, Matt; Nodder, Scott D.; Gutiérrez-Rodríguez, Andres; Safi, Karl; Brown, Julie C. S.; Graham, Laura; Dunbar, Robert B.; Mucciarone, David A.; Magozzi, Sarah; Somes, Chris; Trueman, Clive N. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-30)
      Polar marine ecosystems are particularly vulnerable to the effects of climate change. Warming temperatures, freshening seawater, and disruption to sea-ice formation potentially all have cascading effects on food webs. New approaches are needed to better understand spatiotemporal interactions among biogeochemical processes at the base of Southern Ocean food webs. In marine systems, isoscapes (models ...
    • Seasonal variability in non-consumptive mortality of Arctic zooplankton 

      Daase, Malin; Søreide, Janne E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-04)
      Recent observations from high-latitude marine ecosystems indicate that non-consumptive mortality may be particularly high in Arctic zooplankton during the polar night. Here we have estimated the contribution of dead organisms to the mesozooplankton community in the high Arctic (Svalbard 78–81oN) during the polar night (January), in spring (May) and in late summer (end of August). To identify in situ ...
    • Research gaps and trends in the Arctic tundra: a topic-modelling approach 

      Ancin Murguzur, Francisco Javier; Hausner, Vera Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-18)
      Climate change is affecting the biodiversity, ecosystem services and the well-being of people that live in the Arctic tundra. Understanding the societal implications and adapting to these changes depend on knowledge produced by multiple disciplines. We analysed peer-reviewed publications to identify the main research themes relating to the Arctic tundra and assessed to what extent current research ...
    • A refined method to monitor arousal from hibernation in the European hamster 

      Fasth Markussen, Fredrik Andreas; Melum, Vebjørn Jacobsen; Hazlerigg, David (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-07)
      Background - Hibernation is a physiological and behavioural adaptation that permits survival during periods of reduced food availability and extreme environmental temperatures. This is achieved through cycles of metabolic depression and reduced body temperature (torpor) and rewarming (arousal). Rewarming from torpor is achieved through the activation of brown adipose tissue (BAT) associated with a ...
    • Using subnivean camera traps to study arctic small mammal community dynamics during winter 

      Mölle, Jonas; Kleiven, Eivind Flittie; Ims, Rolf Anker; Soininen, Eeva M (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-12)
      Small rodents are a key indicator to understand the effect of rapidly changing winter climate on Arctic tundra ecosystems. However, monitoring rodent populations through the long Arctic winter by means of conventional traps has, until now, been hampered by snow cover and harsh ambient conditions. Here, we conduct the first extensive assessment of the utility of a newly developed camera trap to ...
    • The influence of above-ground herbivory on the response of arctic soil methanotrophs to increasing ch4 concentrations and temperatures 

      Rainer, Edda Marie; Seppey, Victor William Christophe; Hammer, Caroline; Svenning, Mette Marianne; Tveit, Alexander (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-02)
      Rising temperatures in the Arctic affect soil microorganisms, herbivores, and peatland vegetation, thus directly and indirectly influencing microbial CH<sub>4</sub> production. It is not currently known how methanotrophs in Arctic peat respond to combined changes in temperature, CH<sub>4</sub> concentration, and vegetation. We studied methanotroph responses to temperature and CH<sub>4</sub> ...
    • Welcome to the Family: Identification of the NAD+ Transporter of Animal Mitochondria as Member of the Solute Carrier Family SLC25 

      Monnè, Magnus; Nikiforov, Andrey; Heiland, Ines; Agrimi, Gennaro; Ziegler, Mathias; Palmieri, Ferdinando (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-14)
      Subcellular compartmentation is a fundamental property of eukaryotic cells. Communication and metabolic and regulatory interconnectivity between organelles require that solutes can be transported across their surrounding membranes. Indeed, in mammals, there are hundreds of genes encoding solute carriers (SLCs) which mediate the selective transport of molecules such as nucleotides, amino acids, ...
    • Context-dependent fitness costs of reproduction despite stable body mass costs in an Arctic herbivore 

      Pigeon, Gabriel; Albon, Steve; Loe, Leif Egil; Bischof, Richard; Bonenfant, Christophe; Ropstad, Erik; Veiberg, Vebjørn; Stien, Audun (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-20)
      1.The cost of reproduction on demographic rates is often assumed to operate through changing body condition. Several studies have found that reproduction depresses body mass more if the current conditions are severe, such as high population densities or adverse weather, than under benign environmental conditions. However, few studies have investigated the association between the fitness components ...
    • Feeding at the front line: Interannual variation in the use of glacier fronts by foraging black-legged kittiwakes 

      Bertrand, Philip; Strøm, Hallvard; Bêty, Joël; Steen, Harald; Kohler, Jack; Vihtakari, Mikko; Van Pelt, Ward; Yoccoz, Nigel Gilles; Hop, Haakon; Harris, Stephanie M.; Patrick, Samantha C.; Assmy, Philipp; Wold, Anette; Duarte, Pedro; Moholdt, Geir; Descamps, Sébastien (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-28)
      Tidewater glacier fronts can represent important foraging areas for Arctic predators. Their ecological importance is likely to change in a warmer Arctic. Their profitability and use by consumers are expected to vary in time, but the underlying mechanisms driving such variation remain poorly known. The subglacial plume, originating from meltwater discharge, is responsible for the entrainment and ...
    • Information Requirements under the Essential-Use Concept: PFAS Case Studies 

      Glüge, Juliane; London, Rachel; Cousins, Ian T.; Dewitt, Jamie; Goldenman, Gretta; Herzke, Dorte; Lohmann, Rainer; Miller, Mark; Ng, Carla A.; Patton, Sharyle; Trier, Xenia; Wang, Zhanyun; Scheringer, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-05)
      Per- and polyfluoroalkyl substances (PFAS) are a class of substances for which there are widespread concerns about their extreme persistence in combination with toxic effects. It has been argued that PFAS should only be employed in those uses that are necessary for health or safety or are critical for the functioning of society and where no alternatives are available (“essential-use concept”). ...
    • Can a key boreal Calanus copepod species now complete its life-cycle in the Arctic? Evidence and implications for Arctic food-webs 

      Tarling, Geraint A.; Freer, Jennifer J.; Banas, Neil S.; Belcher, Anna; Blackwell, Mayleen; Castellani, Claudia; Cook, Kathryn B.; Cottier, Finlo Robert; Daase, Malin; Johnson, Magnus L.; Last, Kim S.; Lindeque, Penelope K.; Mayor, Daniel J.; Mitchell, Elaine; Parry, Helen E.; Speirs, Douglas C.; Stowasser, Gabriele; Wootton, Marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-29)
      The changing Arctic environment is affecting zooplankton that support its abundant wildlife. We examined how these changes are influencing a key zooplankton species, Calanus finmarchicus, principally found in the North Atlantic but expatriated to the Arctic. Close to the ice-edge in the Fram Strait, we identified areas that, since the 1980s, are increasingly favourable to C. finmarchicus. Field-sampling ...
    • Breeding den selection by Arctic foxes (Vulpes lagopus) in southern Yamal Peninsula, Russia 

      Hofhuis, Stijn; Ehrich, Dorothee; Sokolova, Natalia A.; van Hooft, Pim; Sokolov, Aleksandr A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-02)
      Selecting the right location for a den during the breeding season is a type of habitat selection in the Arctic fox (Vulpes lagopus) that is likely to affect its reproductive success. A den’s suitability likely depends on its ability to provide shelter, as well as its proximity to prey resources. Depending on the different relative risks that Arctic foxes may face across their broad circumpolar range, ...
    • Effects of a wave power park with no-take zone on decapod abundance and size 

      Bender, Anke; Langhamer, Olivia; Molis, Markus; Sundberg, Jan (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-11)
      Past studies have revealed higher levels of biodiversity, total abundance, and size of individuals around offshore installations of renewable energy. This study investigated the effects of Lysekil wave power park (area 0.5 km2) on the abundance and carapace size of decapods at the Swedish west coast. For that purpose, decapods were caught with cages during four consecutive summers. Two types of ...
    • Issues of under-representation in quantitative DNA metabarcoding weaken the inference about diet of the tundra vole Microtus oeconomus 

      Neby, Magne; Kamenova, Stefaniya; Devineau, Olivier; Ims, Rolf Anker; Soininen, Eeva M (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-26)
      During the last decade, methods based on high-throughput sequencing such as DNA metabarcoding have opened up for a range of new questions in animal dietary studies. One of the major advantages of dietary metabarcoding resides in the potential to infer a quantitative relationship between sequence read proportions and biomass of ingested food. However, this relationship’s robustness is highly dependent ...