Now showing items 1061-1080 of 2050

    • Allochthonous Allelopathy. Effects of Empetrum nigrum chemical interference on plant development 

      Pilsbacher, Anna Katharina (Master thesis; Mastergradsoppgave, 2016-05-20)
      The dwafshrub Empetrum nigrum uses phenolic compounds exuded by its leaves to depress the germination and growth of its surroundings. The allelopathic effect has, only been studied in areas immediately surrounding the plant (autochthonous allelopathy) but not in an open system apptoach that takes into account that a multitude of EMpetrum nigrum leaves get introduced into new environments through ...
    • Species validity of five common northern/Arctic spring bloom diatoms: a combined morphological and molecular study 

      Uradnikova, Martina (Master thesis; Mastergradsoppgave, 2020-02-15)
      Relevant taxonomical morphological characters of five common spring bloom centric diatoms, preliminary identified as Attheya longicornis Crawford & Gardner, Chaetoceros furcellatus Yendo, Porosira glacialis Jørgensen, Coscinodiscus sp. and Skeletonema marinoi Sarno & Zingone were observed and described using light and scanning electron microscope. Further, samples of cultured diatoms were sent to ...
    • End-user involvement to improve predictions and management of populations with complex dynamics and multiple drivers 

      Henden, John-André; Ims, Rolf Anker; Yoccoz, Nigel; Asbjørnsen, Einar Johannes; Stien, Audun; Mellard, Jarad Pope; Tveraa, Torkild; Marolla, Filippo; Jepsen, Jane Uhd (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-11)
      Sustainable management of wildlife populations can be aided by building models that both identify current drivers of natural dynamics and provide near-term predictions of future states. We employed a Strategic Foresight Protocol (SFP) involving stakeholders to decide the purpose and structure of a dynamic state-space model for the population dynamics of the Willow Ptarmigan, a popular game species ...
    • Investigating population genomic structure of salmon lice (Lepeophtheirus salmonis) in northern Norway 

      Banno, Kana (Master thesis; Mastergradsoppgave, 2019-05-14)
      Salmon louse (Lepeophtheirus salmonis) is a parasitic copepod that causes significant damage to Atlantic salmon (Salmo salar) and incurs significant costs to the salmonid aquaculture industry. In Norway, the industry has been coping with salmon lice issues with various methods such as chemical treatments, but it has resulted in an acquisition of resistance in salmon lice towards the existing delousing ...
    • Salmon louse (Lepeophtheirus salmonis (Krøyer)) control methods and efficacy in atlantic salmon (Salmo salar (Linnaeus)) aquaculture: A literature review 

      Cerbule, Kristine; Godfroid, Jacques (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-31)
      The salmon louse (<i>Lepeophtheirus salmonis</i>) causes problems in Atlantic salmon (<i>Salmo salar</i>) aquaculture in the Northern Hemisphere, because infestations can result in both a loss of production and in fish mortality. Several types of treatment have been used to control louse infestations, but these have seen varying success. The aim of this review is to examine the efficacy and safety ...
    • Migration and habitat use of the landlocked riverine Atlantic salmon Salmo salar småblank 

      Davidsen, Jan Grimsrud; Eikås, Linda; Hedger, Richard David; Thorstad, Eva Bonsak; Rønning, Lars; Sjursen, Aslak Darre; Berg, Ole Kristian; Bremset, Gunnbjørn; Karlsson, Sten; Sundt-Hansen, Line Elisabeth Breivik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-18)
      “Småblank” is the only population of Atlantic salmon in Europe living its entire life in the river habitat without performing migrations to the sea or lakes. Home range size and habitat use were compared between an unregulated tributary and hydro-power regulated parts of the main river during 2014–2017. In total, 140 småblank were tagged with radio transmitters and tracked for 4–5 months. Tagged ...
    • Populasjonssykluser hos rype – stor variasjon i rom og tid 

      Henden, John-André; Fuglei, Eva; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-27)
      Fjellrype og lirype har en vid sirkumpolar utbredelse, med populasjoner som ofte har store, sykliske svingninger. Disse rypesyklusenes periodelengde og amplitude varierer imidlertid svært mye i tid og rom. Mens norske rypepopulasjoner har hatt en 3–4-års syklus koplet til smågnagersyklusen, kan rype andre steder i verden ha 9–11-års sykluser koplet til andre arter i økosystemet. Rypedynamikken kan ...
    • Quantifying tourism booms and the increasing footprint in the Arctic with social media data 

      Runge, Claire Alice; Remi, Daigle; Hausner, Vera Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-16)
      Arctic tourism has rapidly increased in the past two decades. We used social media data to examine localized tourism booms and quantify the spatial expansion of the Arctic tourism footprint. We extracted geotagged locations from over 800,000 photos on Flickr and mapped these across space and time. We critically examine the use of social media as a data source in data-poor regions, and find that while ...
    • Kesälaidunnus ei ole ylilaidunnusta 

      Oksanen, Lauri (Journal article; Tidsskriftartikkel, 2019)
    • Tunturit, laidunnus ja kukat: näköaloja Jotunheimilta Pohjoiskalotille 

      Oksanen, Lauri (Journal article; Tidsskriftartikkel, 2019)
    • Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots 

      Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-19)
      In 2007, a possible wreck site was discovered in Trygghamna, Isfjorden, Svalbard by the Norwegian Hydrographic Service. Using (1) a REMUS 100 autonomous underwater vehicle (AUV) equipped with a sidescan sonar (SSS) and (2) a Seabotix LBV 200 mini-remotely operated vehicle (ROV) with a high-definition (HD) camera, the wreck was in 2015 identified as the Figaro: a floating whalery that sank in 1908. ...
    • Advantages and Limitations of Using Mobile Apps for Protected Area Monitoring and Management 

      Muñoz, Lorena; Hausner, Vera Helene; Monz, Christopher (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-18)
      Digital technologies, including participatory Internet mapping, social media and smartphones, provide new avenues for research in outdoor recreation and tourism. The potential to reach a greater audience and collect visitation data on a broader scale, with less costs than traditional paper surveys, are key advantages that have increased the use of these novel technologies. Using of mobile apps for ...
    • Compositional and morphological analyses of wax in northern wild berry species 

      Trivedi, Priyanka; Karppinen, Katja; Klavins, Linards; Kviesis, Jorens; Sundqvist, Petri; Nguyen, Nga; Heinonen, Esa; Klavins, Maris; Jaakola, Laura; Väänänen, Juha; Remes, Janne; Häggman, Hely (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-21)
      Aerial surfaces of plants are covered by a waxy cuticle protecting plants from excessive water loss and UV light. In the present study, composition and morphology of cuticular waxes of northern wild berry species bilberry (<i>Vaccinium myrtillus</i> L.), lingonberry (V. <i>vitis-idaea</i> L.), bog bilberry (V. <i>uliginosum</i> L.) and crowberry (<i>Empetrum nigrum</i> L.) were investigated. Scanning ...
    • The genetic legacy of extreme exploitation in a polar vertebrate 

      Paijmans, Anneke; Stoffel, Martin A.; Bester, Marthán N.; Cleary, Alison Clare; de Bruyn, P.J. Nico; Forcada, Jaume; Goebel, M; Goldsworthy, S.D.; Guinet, Christophe; Lydersen, Christian; Kovacs, Kit M.; Lowther, Andrew; Hoffman, Joseph I. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-20)
      Understanding the effects of human exploitation on the genetic composition of wild populations is important for predicting species persistence and adaptive potential. We therefore investigated the genetic legacy of large-scale commercial harvesting by reconstructing, on a global scale, the recent demographic history of the Antarctic fur seal (Arctocephalus gazella), a species that was hunted to the ...
    • Sami knowledge and ecosystem-based adaptation strategies for managing pastures under threat from multiple land uses 

      Hausner, Vera Helene; Engen, Sigrid; Brattland, Camilla; Fauchald, Per (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-13)
      <ol><li>Ecosystem‐based adaptation (EbA) relies upon the capacity of ecosystems to buffer communities against the adverse impacts of climate change. Maintaining ecosystems that deliver critical services to communities can also provide co‐benefits beyond adaptation, such as climate mitigation and protection of biological diversity and livelihoods. EbA has, to a limited extent, drawn upon indigenous ...
    • 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 ...