Nye registreringer

  • Initial Community Convergence on Plant Defense Syndromes Explains Community Responses to Herbivore Exclosures 

    Robinson, Jacob (Master thesis; Mastergradsoppgave, 2017-11-15)
    General trade-offs in species’ energy use are highlighted here by mapping proposed defense syndromes, using trade-offs found between: constitutive phenolic compounds, silica and a high nutrient low defense region found between regional con-specifics. Differences in species composition between two catchments can be explained by proposed syndrome trade-offs seeking energy use optimums in differing ...
  • Can novel pest outbreaks drive ecosystem transitions in northern-boreal birch forest? 

    Vindstad, Ole Petter Laksforsmo; Jepsen, Jane Uhd; Ek, Malin; Pepi, Adam A.; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-04)
    <p>1.The boreal biome exhibits distinct alternative ecosystem states with high and low levels of tree cover. Insect outbreaks facilitated by climate warming could potentially drive transitions from high to low tree cover states. We investigated whether two key premises for such outbreak‐induced transitions – critical thresholds (tipping points) and positive feedbacks that could maintain alternative ...
  • Climate Events Synchronize the Dynamics of a Resident Vertebrate Community in the High Arctic 

    Hansen, Brage Bremset; Grøtan, Vidar; Aanes, Ronny; Sæther, Bernt-Erik; Stien, Audun; Fuglei, Eva; Ims, Rolf Anker; Yoccoz, Nigel; Pedersen, Åshild Ønvik (Peer reviewed; Research report; Forskningsrapport, 2013-01-18)
    Recently accumulated evidence has documented a climate impact on the demography and dynamics of single species, yet the impact at the community level is poorly understood. Here, we show that in Svalbard in the high Arctic, extreme weather events synchronize population fluctuations across an entire community of resident vertebrate herbivores and cause lagged correlations with the secondary consumer, ...
  • Seasonal changes in background levels of deuterium and oxygen- 18 prove water drinking by harp seals, which affects the use of the doubly labelled water method 

    Nordøy, Erling Sverre; Lager, Anne Regine; Schots, Pauke C. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-29)
    The aim of this study was to monitor seasonal changes in stable isotopes of pool freshwater and harp seal (Phoca groenlandica) body water, and to study whether these potential seasonal changes might bias results obtained using the doubly labelled water (DLW) method when measuring energy expenditure in animals with access to freshwater. Seasonal changes in the background levels of deuterium and ...
  • Bacterial response to permafrost derived organic matter input in an Arctic fjord 

    Müller, Oliver; Seuthe, Lena; Bratbak, Gunnar; Paulsen, Maria Lund (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-06)
    The warming of the Arctic causes increased riverine discharge, coastal erosion, and the thawing of permafrost. Together, this is leading to an increased wash out of terrestrial dissolved organic matter (tDOM) into the coastal Arctic ecosystems. This tDOM may be anticipated to affect both carbon and nutrient flow in the microbial food web and microbial community composition, but there are few ...
  • Abscisic acid regulates anthocyanin biosynthesis and gene expression associated with cell wall modification in ripening bilberry (vaccinium myrtillus l.) fruits 

    Karppinen, Katja Hannele; Tegelberg, Pinja; Häggman, Hely; Jaakola, Laura (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-29)
    Ripening of non-climacteric bilberry (Vaccinium myrtillus L.) fruit is characterized by a high accumulation of health-beneficial anthocyanins. Plant hormone abscisic acid (ABA) and sucrose have been shown to be among the central signaling molecules coordinating non-climacteric fruit ripening and anthocyanin accumulation in some fruits such as strawberry. Our earlier studies have demonstrated an ...
  • Transferability of biotic interactions: temporal consistency of arctic plant-rodent relationships is poor 

    Soininen, Eeva M; Henden, John-André; Ravolainen, Virve; Yoccoz, Nigel Gilles; Bråthen, Kari Anne; Killengreen, Siw Turid; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-17)
    Variability in biotic interaction strength is an integral part of food web functioning. However, the consequences of the spatial and temporal variability of biotic interactions are poorly known, in particular for predicting species abundance and distribution. The amplitude of rodent population cycles (i.e., peak-phase abundances) has been hypothesized to be determined by vegetation properties ...
  • First record of a rare species, Polyasterias problematica (Prasinophyceae), in Balsfjord, northern Norway 

    Kubiszyn, Anna M; Svensen, Camilla (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-13)
    <i>Polyasterias problematica</i> is a poorly investigated prasinophyte species, practically known only from a few, primarily historical studies. Fragmentary information on the species indicates that <i>P. problematica</i> is mainly distributed in the euphotic zone of the Canadian and Russian Arctic, Atlantic Canada, the mid-Atlantic and some European seas. Here, we present the first record of this ...
  • Hva forskerne egentlig gjør 

    Wiedmann, Ingrid (Chronicle; Kronikk, 2018-10-19)
    <p><i>Introduction</i>: Forskningsdagene ved UiT Norges arktiske universitet, åpen dag ved Framsenteret, ulike arrangement rundt UiTs 50 års jubileum og en UiT spesialforestilling på Hålogaland teater: Forskningen i Tromsø har vist seg seg fram denne høsten. Uansett hvor du går i Tromsø, så formidler forskere til deg at forskning er spennende og at det er kjempegøy å være forsker. Som forsker står ...
  • Seroprevalence for Brucella spp. in Baltic ringed seals (Phoca hispida) and East Greenland harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals 

    Sonne, Christian; Andersen-Ranberg, Emilie; Rajala, Elisabeth; Agerholm, Jørgen S.; Bonefeld-Jørgensen, Eva; Desforges, Jean-Pierre; Eulaers, Igor; Jenssen, Bjørn Munro; Koch, Anders; Rosings-Asvid, Aqqualu; Siebert, Ursula; Tryland, Morten; Mulvad, Gert; Härkönen, Tero; Acquarone, Mario; Nordøy, Erling Sverre; Dietz, Rune; Magnusson, Ulf (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-12)
    Zoonotic infections transmitted from marine mammals to humans in the Baltic and European Arctic are of unknown significance, despite given considerable potential for transmission due to local hunt. Here we present results of an initial screening for <i>Brucella</i> spp. in Arctic and Baltic seal species. Baltic ringed seals (<i>Pusa hispida</i>, n = 12) sampled in October 2015 and Greenland Sea harp ...
  • Choose your poison – Space-use strategy influences pollutant exposure in Barents Sea polar bears 

    Tartu, Sabrina; Aars, Jon; Andersen, Magnus; Polder, Anuschka; Bourgeon, Sophie; Merkel, Benjamin; Lowther, Andrew D.; Bytingsvik, Jenny; Welker, Jeffrey Martin; Derocher, Andrew E.; Jenssen, Bjørn Munro; Routti, Heli (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-24)
    Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000–2014, n = 152). First, ...
  • Hyperbenthic food-web structure in an Arctic fjord 

    McGovern, Maeve; Berge, Jørgen; Szymczycha, Beata; Węsławski, Jan Marcin; Renaud, Paul Eric (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-17)
    Current knowledge of the Arctic marine ecosystem is based primarily on studies performed during the polar day on the pelagic and benthic realms. Both the polar night and the hyperbenthic layer remain as substantial knowledge gaps in our understanding of the marine system at high latitudes. This study investigated the hyperbenthic food web in Kongsfjord, a high-latitude, ice-free fjord, in September ...
  • Photoperiod revisited: is there a critical day length for triggering a complete parr–smolt transformation in Atlantic salmon Salmo salar? 

    Strand, Jo Espen Tau; Hazlerigg, David; Jørgensen, Even Hjalmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-26)
    The present study investigated whether there is a critical length of photoperiod needed to stimulate a completed parr–smolt transformation (PST) in Atlantic salmon <i>Salmo salar</i>. In two experiments, <i>S. salar</i> parr of the Norwegian aquaculture strain held on continuous light were exposed to a short photoperiod (6 L:18D) followed by exposure to 8 L:16D, 12 L:12D, 16 L:8D, 20 L:4D and 24 ...
  • A Comparative Study on the Faecal Bacterial Community and Potential Zoonotic Bacteria of Muskoxen (Ovibos moschatus) in Northeast Greenland, Northwest Greenland and Norway 

    Andersen-Ranberg, Emilie; Barnes, Christopher J; Rasmussen, Linett; Salgado-Flores, Alejandro; Grøndahl, Carsten; Mosbacher, Jesper Bruun; Hansen, Anders J.; Sundset, Monica Alterskjær; Schmidt, Niels Martin; Christian, Sonne (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-25)
    Muskoxen (<i>Ovibos moschatus</i>) are ruminants adapted to a high-fibre diet. There is increasing interest in the role that gut microbes play in the digestion and utilization of these specialized diets but only limited data available on the gut microbiome of high-Arctic animals. In this study, we metabarcoded the 16S rRNA region of faecal samples from muskoxen of Northeast Greenland, Northwest ...
  • Seasonal difference in temporal transferability of an ecological model: near-term predictions of lemming outbreak abundances 

    Kleiven, Eivind Flittie; Henden, John-André; Ims, Rolf Anker; Yoccoz, Nigel Gilles (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-15)
    Ecological models have been criticized for a lack of validation of their temporal transferability. Here we answer this call by investigating the temporal transferability of a dynamic state-space model developed to estimate season-dependent biotic and climatic predictors of spatial variability in outbreak abundance of the Norwegian lemming. Modelled summer and winter dynamics parametrized by spatial ...
  • Methylmercury biomagnification in an Arctic pelagic food web 

    Ruus, Anders; Øverjordet, Ida Beathe; Braaten, Hans Fredrik Veiteberg; Evenset, Anita; Christensen, Guttorm N.; Heimstad, Eldbjørg Sofie; Gabrielsen, Geir W.; Borgå, Katrine (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-14)
    Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. ...
  • Seasonal variation in transport of zooplankton into the Arctic Basin through the Atlantic gateway, Fram Strait 

    Basedow, Sünnje Linnéa; Sundfjord, Arild; von Appen, Wilken-Jon; Halvorsen, Elisabeth; Kwasniewski, Slawomir; Reigstad, Marit (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-04)
    The largest contribution of oceanic heat to the Arctic Ocean is the warm Atlantic Water (AW) inflow through the deep Fram Strait. The AW current also carries Atlantic plankton into the Arctic Basin and this inflow of zooplankton biomass through the Atlantic-Arctic gateway far exceeds the inflow through the shallow Pacific-Arctic gateway. However, because this transport has not yet been adequately ...
  • Recruitment of benthic invertebrates in high Arctic fjords: Relation to temperature, depth, and season 

    Meyer, Kirstin S.; Sweetman, Andrew K; Kuklinski, Piotr; Leopold, Peter; Vogedes, Daniel Ludwig; Berge, Jørgen; Griffith, Colin; Young, Craig M; Renaud, Paul (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-30)
    In the high Arctic, recruitment of hard-bottom benthic organisms has been studied at single locations, but little is known about how it varies spatially or temporally, or how it is influenced by abiotic factors. In this study, settlement plates were simultaneously deployed at five locations in three Svalbard (Norway) fjords at depths ranging from 7 m to 215 m. Recruitment was significantly different ...
  • Health and environmental risk assessment of microbial cleaning products. Scientific Opinion of the Panel on Microbial Ecology of the Norwegian Scientific Committee for Food Safety 

    Skaar, Ida; Asare, Nana Yaa Ohene; Godfroid, Jacques; Jelmert, Anders; Ytrehus, Bjørnar (Research report, 2016-08-18)
    In 2015, The Norwegian Environment Agency requested the Norwegian Scientific Committee for Food Safety (VKM) to provide a scientific assessment of the information requirements laid down in the declaration form for the Regulation on microbial products and its guidelines, if these are sufficient to conduct a health and environmental risk assessment of the use of microbial cleaning products in ...
  • Contrasting physiological responses to future ocean acidification among Arctic copepod populations 

    Thor, Peter; Bailey, Allison Michelle; Dupont, Sam; Calosi, Piero; Søreide, Janne; De Wit, Pierre; Guscelli, Ella; Loubet-Sartrou, Lea; Deichmann, Ida M.; Candee, Martin M.; Svensen, Camilla; King, Andrew Luke; Bellerby, Richard (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-17)
    Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognized as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid‐base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across ...

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