Now showing items 881-900 of 1632

    • Identifying spatial overlap in the values of locals, domestic- and international tourists to protected areas 

      Muñoz, Lorena; Hausner, Vera Helene; Brown, Greg; Runge, Claire Alice; Fauchald, Per (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-22)
      Nature-based tourism is increasingly encouraged to support local socioeconomic development in and around protected areas, but managing protected areas for tourism could challenge existing park uses associated with self-organized outdoor recreation and local resource use. We used a web-based Public Participatory Geographic Information System (PPGIS) to identify the most important places and values ...
    • Marine CO2 system variability in a high arctic tidewater-glacier fjord system, Tempelfjorden, Svalbard 

      Ericson, Ylva; Falck, Eva; Chierici, Melissa; Fransson, Agneta Ingrid; Kristiansen, Svein (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-04)
      The marine CO<sub>2</sub> system in Tempelfjorden (Svalbard) was investigated between August 2015 and December 2017 using total alkalinity, pH, temperature, salinity, oxygen isotopic ratio, and nutrient data. Primary production resulted in the largest changes that were observed in the partial pressure of CO<sub>2</sub> (<i>p</i>CO<sub>2</sub>, 140 μatm) and the saturation state of aragonite ...
    • Vertical export of marine pelagic protists in an ice-free high-Arctic fjord (Adventfjorden, West Spitsbergen) throughout 2011-2012 

      Marquardt, Miriam; Skogseth, Ragnheid; Wiedmann, Ingrid; Vader, Anna; Reigstad, Marit; Cottier, Finlo Robert; Gabrielsen, Tove M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-06)
      The ecosystem role of Arctic microbial communities is still largely unknown. Based on a time-series study at the IsA station (West Spitsbergen), the seasonality and contribution of pelagic protists to the vertical flux was investigated at 7 time points during 2011-2012. The hydrography of this high-Arctic fjord was evaluated to identify impacts on the community composition during the different ...
    • Large loss of CO2 in winter observed across the northern permafrost region 

      Natali, Susan M.; Watts, Jennifer D.; Rogers, Brendan M.; Potter, Stefano; Ludwig, Sarah M.; Selbmann, Anne-Katrin; Sullivan, Patrick F.; Abbott, Benjamin W.; Arndt, Kyla A.; Birch, Leah; Björkman, Mats P.; Bloom, A. Anthony; Celis, Gerardo; Christensen, Torben R.; Christiansen, Casper Tai; Commane, Roisin; Cooper, Elisabeth J.; Crill, Patrick; Czimczik, Claudia; Davydov, Sergey; Du, Jinyang; Egan, Jocelyn E.; Elberling, Bo; Euskirchen, Eugenie S.; Friborg, Thomas; Genet, Hélène; Göckede, Mathias; Goodrich, Jordan P.; Grogan, Paul; Helbig, Manuel; Jafarov, Elchin E.; Jastrow, Julie D.; Kalhori, Aram A. M.; Kim, Yongwon; Kimball, John S.; Kutzbach, Lars; Lara, Mark J.; Larsen, Klaus S.; Lee, Bang-Yong; Liu, Zhihua; Loranty, Michael M.; Lund, Magnus; Lupascu, Massimo; Madani, Nima; Malhotra, Avni; Matamala, Roser; McFarland, Jack; McGuire, A. David; Michelsen, Anders; Minions, Christina; Oechel, Walter C.; Olefeldt, David; Parmentier, Frans-Jan W.; Pirk, Norbert; Poulter, Ben; Quinton, William; Rezanezhad, Fereidoun; Risk, David; Sachs, Torsten; Schaefer, Kevin; Schmidt, Niels M.; Schuur, Edward A. G.; Semenchuk, Philipp R.; Shaver, Gaius; Sonnentag, Oliver; Starr, Gregory; Treat, Claire C.; Waldrop, Mark P.; Wang, Yihui; Welker, Jeffrey; Wille, Christian; Xu, Xiaofeng; Zhang, Zhen; Zhuang, Qianlai; Zona, Donatella (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-21)
      Recent warming in the Arctic, which has been amplified during the winter, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO<sub>2</sub>). However, the amount of CO<sub>2</sub> released in winter is not known and has not been well represented by ecosystem models or empirically based estimates. Here we synthesize regional in situ observations ...
    • A raster version of the Circumpolar Arctic Vegetation Map (CAVM) 

      Raynolds, Martha K.; Walker, Donald A.; Balser, Andrew; Bay, Christian; Campbell, Mitch; Cherosov, Mikhail M.; Daniëls, Fred J.A.; Eidesen, Pernille Bronken; Ermokhina, Ksenia A.; Frost, Gerald V.; Jedrzejek, Birgit; Jorgenson, M. Torre; Kennedy, Blair E.; Kholod, Sergei S.; Lavrinenko, Igor A.; Lavrinenko, Olga V.; Magnússon, Borgþór; Matveyeva, Nadezhda V.; Metúsalemsson, Sigmar; Nilsen, Lennart; Olthof, Ian; Pospelov, Igor N.; Pospelova, Elena B.; Pouliot, Darren; Razzhivin, Vladimir; Schaepman-Strub, Gabriela; Šibík, Jozef; Telyatnikov, Mikhail Yu.; Troeva, Elena (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-17)
      Land cover maps are the basic data layer required for understanding and modeling ecological patterns and processes. The Circumpolar Arctic Vegetation Map (CAVM), produced in 2003, has been widely used as a base map for studies in the arctic tundra biome. However, the relatively coarse resolution and vector format of the map were not compatible with many other data sets. We present a new version of ...
    • A transdisciplinary approach to Brucella in Muskoxen of the Western Canadian Arctic 1989-2016 

      Tomaselli, Matilde; Elkin, Brett T.; Kutz, Susan; Harms, Naomi Jane; Nymo, Ingebjørg Helena; Davison, Tracy; Leclerc, Lise-Marie; Branigan, Marsha; Dumond, Mathieu; Tryland, Morten; Checkley, Sylvia L. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-14)
      Brucella serostatus was evaluated in 3189 muskoxen sampled between 1989 and 2016 from various locations of the Canadian Arctic archipelago and mainland, near the communities of Sachs Harbour and Ulukhaktok, Northwest Territories, and Cambridge Bay and Kugluktuk, Nunavut. Brucella antibodies were found only in muskoxen sampled around Cambridge Bay, both on southern Victoria Island and on the adjacent ...
    • Seasonal patterns in species diversity across biomes 

      Mellard, Jarad P.; Audoye, Pauline; Loreau, Michel (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-30)
      A conspicuous season–diversity relationship (SDR) can be seen in seasonal environments, often with a defined peak in active species diversity in the growing season. We ask is this a general pattern and are other patterns possible? In addition, we ask what is the ultimate cause of this pattern and can we understand it using existing ecological theory? To accomplish this task, we assembled a global ...
    • Circumpolar patterns of Arctic freshwater fish biodiversity: A baseline for monitoring 

      Laske, Sarah M.; Amundsen, Per-Arne; Christoffersen, Kirsten Seestern; Erkinaro, Jaakko; Guðbergsson, Guðni; Hayden, Brian; Heino, Jani; Holmgren, Kerstin; Kahilainen, Kimmo Kalevi; Lento, Jennifer; Orell, Panu; Östergren, Jan; Power, Michael; Rafikov, Ruslan; Romakkaniemi, Atso; Svenning, Martin; Swanson, Heidi; Whitman, Matthew; Zimmerman, Christian E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-01)
      Climate change, biological invasions, and anthropogenic disturbance pose a threat to the biodiversity and function of Arctic freshwater ecosystems. Understanding potential changes in fish species distribution and richness is necessary, given the great importance of fish to the function of freshwater ecosystems and as a resource to humans. However, information gaps limit large‐scale studies and our ...
    • Widespread soil bacterium that oxidizes atmospheric methane 

      Tveit, Alexander Tøsdal; Hestnes, Anne Grethe; Robinson, Serina Lee; Schintlmeister, Arno; Dedysh, Svetlana N; Jehmlich, Nico; Bergen, Martin von; Herbold, Craig; Wagner, Michael; Richter, Andreas; Svenning, Mette Marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-08)
      Increasing atmospheric methane concentrations contribute significantly to global warming. The only known biological sink for atmospheric methane is oxidation by methane oxidizing bacteria (MOB). Due to the lack of pure cultures, the physiology and metabolic potential of MOB that oxidize atmospheric methane remains a mystery. Here, we report on isolation and characterization of a MOB that can grow ...
    • DNA double‐strand breaks in Arctic char (Salvelinus alpinus) from Bjørnøya in the Norwegian Arctic 

      Neerland, Eirik D.; Bytingsvik, Jenny; Nikiforov, Vladimir; Evenset, Anita; Krøkje, Åse (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-25)
      High levels of organochlorine contaminants (OCs) have been found in arctic char (<i>Salvelinus alpinus</i>) from Lake Ellasjøen, Bjørnøya (Norwegian Arctic). The aim of the present study was to investigate the potential genotoxic effect of environmental organochlorine contaminant exposure in arctic char from Ellasjøen compared with arctic char from the low‐contaminated Lake Laksvatn nearby. Blood ...
    • Thermal habitat of adult Atlantic salmon Salmo salar in a warming ocean 

      Strøm, John Fredrik; Thorstad, Eva Bonsak; Rikardsen, Audun (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-29)
      The year‐round thermal habitat at sea for adult Atlantic salmon <i>Salmo salar</i> (<i>n</i> = 49) from northern Norway was investigated using archival tags over a 10 year study period. During their ocean feeding migration, the fish spent 90% of the time in waters with temperatures from 1.6–8.4°C. Daily mean temperatures ranged from −0.5 to 12.9°C, with daily temperature variation up to 9.6°C. Fish ...
    • Temporal trend of mercury in relation to feeding habits and food availability in arctic foxes (Vulpes lagopus) from Svalbard, Norway 

      Hallanger, Ingeborg G.; Fuglei, Eva; Yoccoz, Nigel Gilles; Pedersen, Åshild Ønvik; König, Max; Routti, Heli Anna Irmeli (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-20)
      We investigated the temporal trend of mercury (Hg) in arctic foxes from Svalbard, Norway sampled in the period 1997–2014 (<i>n</i> = 109, from 11 trapping seasons). We used linear models to investigate the effect of trapping season, feeding habits (δ<sup>13</sup>C), food availability from marine and terrestrial ecosystems (reindeer carcasses and sea ice cover), sex, age and body condition on liver ...
    • Disappearing green: Shrubs decline and bryophytes increase with nine years of increased snow accumulation in the High Arctic 

      Cooper, Elisabeth J.; Little, Chelsea J.; Pilsbacher, Anna Katharina; Mörsdorf, Martin Alfons (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-25)
      <i>Question</i> - How does increased snow depth affect plant community composition of High Arctic tundra, and can the Normalized Differential Vegetation Index (NDVI) detect induced changes?<p><p> <i>Location</i> - Adventdalen, Spitsbergen, Svalbard (78°10′ N, 16°04′ E).<p><p> <i>Methods</i> - We manipulated snow depth on the tundra using fences, resulting in <i>Deep, Medium</i>, and ...
    • Feeding studies take guts - critical review and recommendations of methods for stomach contents analysis in fish 

      Amundsen, Per-Arne; Sanchez-Hernandez, Javier (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-07)
      Studies on the feeding ecology of fish are essential for exploring and contrasting trophic interactions and population and community dynamics within and among aquatic ecosystems. In this respect, many different methods have been adopted for the analysis of fish stomach contents. No consensus has, however, been reached for a standardised methodology despite that for several decades there has been an ...
    • Selective mineral transport barriers at Cuscuta-host infection sites 

      Förste, Frank; Mantouvalou, Ioanna; Kanngiesser, Birgit; Stosnach, Hagen; Lachner, Lena Anna-Maria; Fischer, Karsten; Krause, Kirsten (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-11)
      The uptake of inorganic nutrients by rootless parasitic plants, which depend on host connections for all nutrient supplies, is largely uncharted. Using X‐ray fluorescence spectroscopy (XRF), we analyzed the element composition of macro‐ and micronutrients at infection sites of the parasitic angiosperm <i>Cuscuta reflexa</i> growing on hosts of the genus <i>Pelargonium</i>. Imaging methods combining ...
    • Environmental filtering and phylogenetic clustering correlate with the distribution patterns of cryptic protist species 

      Singer, David; Kosakyan, Anush; Seppey, Christophe Victor W.; Pillonel, Amandine; Fernandez, Leonardo D; Fontaneto, Diego; Mitchell, Edward A.D.; Lara, Enrique (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-29)
      The community composition of any group of organisms should theoretically be determined by a combination of assembly processes including resource partitioning, competition, environmental filtering, and phylogenetic legacy. Environmental DNA studies have revealed a huge diversity of protists in all environments, raising questions about the ecological significance of such diversity and the degree to ...
    • Tipping point in plant-fungal interactions under severe drought causes abrupt rise in peatland ecosystem respiration 

      Jassey, Vincent E.J.; Reczuga, Monika Katarzyna; Zielinska, Malgorzata; Slowinska, Sandra; Robroek, Bjorn J M; Mariotte, Pierre; Seppey, Christophe Victor W.; Lara, Enrique; Barabach, Jan; Slowinski, Michal; Bragazza, Luca; Chojnicki, Bogdan H.; Lamentowicz, Mariusz; Mitchell, Edward A.D.; Buttler, Alexandre (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-09)
      Ecosystems are increasingly prone to climate extremes, such as drought, with long‐lasting effects on both plant and soil communities and, subsequently, on carbon (C) cycling. However, recent studies underlined the strong variability in ecosystem's response to droughts, raising the issue of nonlinear responses in plant and soil communities. The conundrum is what causes ecosystems to shift in response ...
    • Comparative vegetation survey with focus on cryptogamic covers in the high Arctic along two differing catenas 

      Kern, Ramona; Hotter, Vivien; Frossard, Aline; Albrecht, Martin; Baum, Christel; Tytgat, Bjorn; de Maeyer, Lotte; Velázquez, David; Seppey, Christophe Victor W.; Frey, Beat; Plotze, Michael; Verleyen, Elie; Quesada, Antonio; Svenning, Mette Marianne; Glaser, Karin; Karsten, Ulf (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-24)
      Although cryptogamic covers are important ecosystem engineers in high Arctic tundra, they were often neglected in vegetation surveys. Hence we conducted a systematic survey of cryptogamic cover and vascular plant coverage and composition at two representative, but differing Arctic sites (Ny-Ålesund, Svalbard) along catenas with a natural soil moisture gradient, and integrated these data with ...
    • Discontinuity in the molecular neuroendocrine response to increasing daylengths in Ile-de-France ewes: Is transient Dio2 induction a key feature of circannual timing? 

      Dardente, Hugues; Lomet, Didier; Chesneau, Didier; Pellicer-Rubio, Maria-Teresa; Hazlerigg, David (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-24)
      In mammals, melatonin is responsible for the synchronisation of seasonal cycles to the solar year. Melatonin is secreted by the pineal gland with a profile reflecting the duration of the night and acts via the pituitary pars tuberalis (PT), which in turn modulates hypothalamic thyroid hormone status via seasonal changes in the production of locally‐acting thyrotrophin. Recently, we demonstrated that, ...
    • Relationship between carbon- and oxygen-based primary productivity in the Arctic Ocean, svalbard archipelago 

      Sanz-Martín, Marina; Vernet, Maria; Cape, Mattias R.; Cano, Elena M; Delgado-Huertas, Antonio; Reigstad, Marit; Wassmann, Paul; Duarte, Carlos M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-02)
      Phytoplankton contribute half of the primary production (PP) in the biosphere and are the major source of energy for the Arctic Ocean ecosystem. While PP measurements are therefore fundamental to our understanding of marine biogeochemical cycling, the extent to which current methods provide a definitive estimate of this process remains uncertain given differences in their underlying approaches, and ...