Viser treff 952-971 av 1513

    • Niches of marine mammals in the European Arctic 

      MacKenzie, Kirsteen M.; Lydersen, Christian; Haug, Tore; Routti, Heli Anna Irmeli; Aars, Jon; Andvik, Clare Margaret; Borgå, Katrine; Fisk, A.T.; Meier, Sonnich; Biuw, Martin; Lowther, Andrew; Lindstrøm, Ulf Ove; Kovacs, Kit M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-11)
      The Arctic is warming rapidly, with concomitant sea ice losses and ecosystem changes. The animals most vulnerable to Arctic food web changes are long-lived and slow-growing such as marine mammals, which may not be able to adapt rapidly enough to respond to changes in their resource bases. To determine the current extent and sources of these resource bases, we examined isotopic and trophic niches ...
    • Nitrate supply and uptake in the Atlantic Arctic sea ice zone: seasonal cycle, mechanisms and drivers 

      Henley, Sian F.; Porter, Marie; Hobbs, Laura; Braun, Judith; Guillaume-Castel, Robin; Venables, Emily J.; Dumont, Estelle; Cottier, Finlo Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-31)
      Nutrient supply to the surface ocean is a key factor regulating primary production in the Arctic Ocean under current conditions and with ongoing warming and sea ice losses. Here we present seasonal nitrate concentration and hydrographic data from two oceanographic moorings on the northern Barents shelf between autumn 2017 and summer 2018. The eastern mooring was sea ice-covered to varying degrees ...
    • No evidence for leaf-trait dissimilarity effects on litter decomposition, fungal decomposers, and nutrient dynamics 

      Frainer, Andre Barbosa; Moretti, Marcelo S.; Xu, Wenjing; Gessner, Mark O. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02)
      Biodiversity and ecosystem-functioning theory suggest that litter mixtures composed of dissimilar leaf species can enhance decomposition due to species trait complementarity. Here we created a continuous gradient of litter chemistry trait variability within species mixtures to assess effects of litter dissimilarity on three related processes in a natural stream: litter decomposition, fungal biomass ...
    • No longer tracking greenery in high altitudes: Pastoral practices of Rupshu nomads and their implications for biodiversity conservation 

      Singh, Navinder; Bhatnagar, Yash Veer; Lecomte, Nicolas; Fox, Joseph L.; Yoccoz, Nigel (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Nomadic pastoralism has thrived in Asia’s rangelands for several millennia by tracking seasonal changes in forage productivity and coping with a harsh climate. This pastoralist lifestyle, however, has come under intense transformations in recent decades due to socio-political and land use changes. One example is of the high-altitude trans-Himalayan rangelands of the Jammu and Kashmir State in ...
    • No observed developmental effects in early life stages of capelin (Mallotus villosus) exposed to a water-soluble fraction of crude oil during embryonic development 

      Nahrgang, Jasmine; Granlund, Adina Cassandra; Bender, Morgan Lizabeth; Sørensen, Lisbet; Greenacre, Michael; Frantzen, marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-12)
      The rise in offshore oil and gas operations, maritime shipping, and tourism in northern latitudes enhances the risk of oil spills to sub-Arctic and Arctic coastal environments. Therefore, there is a need to understand the potential adverse effects of petroleum on key species in these areas. Here, we investigated the effects of oil exposure on the early life stages of capelin (Mallotus villosus), ...
    • No support for cryptic choice by ovarian fluid in an external fertilizer 

      Kleppe, April Snøfrid; Nordeide, Jarle Tryti; Rudolfsen, Geir; Figenschou, Lars; Larsen, Berner; Reiss, Katrin; Folstad, Ivar (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-22)
      Whether the ovarian fluid (OF) represents a selective environment influencing cryp‐tic female choice was tested using an external fertilizer experiencing intense sperm competition and large effects of OF on sperm swimming behavior—the Arctic charr (<i>Salvelinus alpinus</i>). We physically separated the OF from the eggs of reproductively active females and reintroduced either their ...
    • Nomadic pastoralism in the Aru basin of Tibet’s Chang Tang. 

      Lhagyal, Dondrup; Næss, Marius W.; Mathiesen, Per; Yangzom, Drolma; Fox, Joseph L.; Bårdsen, Bård J. (Journal article; Peer reviewed; Tidsskriftartikkel, 2004)
      Nomadic pastoralists live at the northern extent of human habitation within the ca. 5000 m elevation Aru basin, in the nortwestern part of the Chang Tang Nature Preserve, Tibet. These nomads herd primarily sheep and goats, a lesser number of yaks, and a few horses. Goats are increasing in importance because of the value of cashmere wool in national and international markets. Although sheep wool ...
    • Northern cod species face spawning habitat losses if global warming exceeds 1.5°C 

      Dahlke, Flemming T.; Butzin, Martin; Nahrgang, Jasmine; Puvanendran, Velmurugu; Mortensen, Atle; Pörtner, Hans-Otto; Storch, Daniela (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-28)
      Rapid climate change in the Northeast Atlantic and Arctic poses a threat to some of the world’s largest fish populations. Impacts of warming and acidification may become accessible through mechanism-based risk assessments and projections of future habitat suitability. We show that ocean acidification causes a narrowing of embryonic thermal ranges, which identifies the suitability of spawning ...
    • Northern expansion is not compensating for southern declines in North American boreal forests 

      Rotbarth, Ronny; Van Nes, Egbert H.; Scheffer, Marten; Jepsen, Jane Uhd; Vindstad, Ole Petter Laksforsmo; Xu, Chi; Holmgren, Milena (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-08)
      Climate change is expected to shift the boreal biome northward through expansion at the northern and contraction at the southern boundary respectively. However, biome-scale evidence of such a shift is rare. Here, we used remotely-sensed tree cover data to quantify temporal changes across theNorth American boreal biome from 2000 to . 2019. We reveal a strong northsouth asymmetry in tree cover change, ...
    • Northern Fennoscandia via the British Isles: evidence for a novel postglacial recolonization route by winter moth (Operophtera brumata) 

      Andersen, Jeremy C.; Havill, Nathan P.; Griffin, Brian P.; Jepsen, Jane U.; Hagen, Snorre B.; Klemola, Tero; Barrio, Isabel C.; Kjeldgaard, Sofie A.; Høye, Toke T.; Murlis, John; Baranchikov, Yuri N.; Selikhovkin, Andrey V.; Vindstad, Ole Petter Laksforsmo; Caccone, Adalgisa; Elkinton, J (Journal article; Tidsskriftartikkel; Peer reviewed, 2021)
      The frequency and severity of outbreaks by pestiferous insects is increasing globally, likely as a result of human-mediated introductions of non-native organisms. However, it is not always apparent whether an outbreak is the result of a recent introduction of an evolutionarily naïve population, or of recent disturbance acting on an existing population that arrived previously during natural range ...
    • The northernmost hyperspectral FLoX sensor dataset for monitoring of high-Arctic tundra vegetation phenology and Sun-Induced Fluorescence (SIF) 

      Tømmervik, Hans; Julitta, Tommaso; Nilsen, Lennart; Park, Taejin; Burkart, Andreas; Ostapowicz, Katarzyna Anna; Karlsen, Stein Rune; Parmentier, Frans-Jan W.; Pirk, Norbert; Bjerke, Jarle W. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-16)
      A hyperspectral field sensor (FloX) was installed in Adventdalen (Svalbard, Norway) in 2019 as part of the Svalbard Integrated Arctic Earth Observing System (SIOS) for monitoring vegetation phenology and Sun-Induced Chlorophyll Fluorescence (SIF) of high-Arctic tundra. This northernmost hyperspectral sensor is located within the footprint of a tower for long-term eddy covariance flux measurements ...
    • Norwegian killer whale movements reflect their different preytypes 

      Vogel, Emma Frances; Rikardsen, AH; Blanchet, Marie-Anne; Blévin, Pierre; Biuw, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-21)
      Norwegian killer whales (Orcinus orca) are thought to be generalists that feed primarily on fish, but some individuals have been observed targeting pinnipeds. In the study reported here, field observations of foraging behaviours formed the basis of a priori classification as either seal-eaters or fish-eaters. Concurrent collection of photographic identification and biopsies for stable isotope analysis ...
    • The Norwegian philosopher Peter Wessel Zapffe(1899-1990) and the Book of Job 

      Dell, Katherine J.; Blix, Arnoldus S (Journal article; Tidsskriftartikkel; Peer reviewed, 2022)
      https://www.dknvs.no/publikasjoner/skrifter/
    • Not only mosses: lemming winter diets as described by DNA metabarcoding 

      Soininen, Eeva M; Zinger, Lucie; Gielly, Ludovic; Yoccoz, Nigel Gilles; Henden, John-André; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-01)
      The temporal dynamics of most tundra food webs are shaped by the cyclic population dynamics of lemmings. While processes during winter may be behind the recent disruptions of lemming cycles, lemming winter ecology is poorly known. We present here the first DNA metabarcoding data on the winter diet of Norwegian lemmings (Lemmus lemmus), based on feces collected after a winter of population ...
    • Novel frontier in wildlife monitoring: Identification of small rodent species from fecal pellets using near-infrared reflectance spectroscopy (NIRS) 

      Tuomi, Maria; Murguzur, Francisco Javier Ancin; Hoset, Katrine S.; Soininen, Eeva M; Vesterinen, Eero J.; Utsi, Tove Aagnes; Kaino, sissel; Bråthen, Kari Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-19)
      Small rodents are prevalent and functionally important across the world's biomes, making their monitoring salient for ecosystem management, conservation, forestry, and agriculture. There is a growing need for cost-effective and noninvasive methods for large-scale, intensive sampling. Fecal pellet counts readily provide relative abundance indices, and given suitable analytical methods, feces could ...
    • A novel use of the leukocyte coping capacity assay to assess the immunomodulatory effects of organohalogenated contaminants in avian wildlife 

      Hansen, Elisabeth; Huber, Nikolaus; Bustnes, Jan Ove; Herzke, Dorte; Bårdsen, Bård-Jørgen; Eulaers, Igor; Johnsen, Trond Vidar; Bourgeon, Sophie (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-19)
      Apex predators are characterized by high levels of biomagnifying organohalogenated contaminants (OHCs) which have been found to induce detrimental health effects in wildlife, such as immune system impairment. The leukocyte coping capacity (LCC) assay is a functional real-time measure of an innate immune response essential in pathogen resistance, known as the respiratory burst. The current study ...
    • A novel use of the leukocyte coping capacity assay to assess the immunomodulatory effects of organohalogenated contaminants in avian wildlife 

      Hansen, Elisabeth; Huber, Nikolaus; Bustnes, Jan Ove; Herzke, Dorte; Bårdsen, Bård-Jørgen; Eulaers, Igor; Johnsen, Trond Vidar; Bourgeon, Sophie (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05)
      Apex predators are characterized by high levels of biomagnifying organohalogenated contaminants (OHCs) which have been found to induce detrimental health effects in wildlife, such as immune system impairment. The leukocyte coping capacity (LCC) assay is a functional real-time measure of an innate immune response essential in pathogen resistance, known as the respiratory burst. The current study ...
    • Numerical responses of saproxylic beetles to rapid increases in dead wood availability following geometrid moth outbreaks in sub-arctic mountain birch forest 

      Laksforsmo Vindstad, Ole Petter; Schultze, Sabrina; Jepsen, Jane Uhd; Biuw, Erik Martin; Kapari, Lauri Teemu; Sverdrup-Thygeson, Anne; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
      Saproxylic insects play an important part in decomposing dead wood in healthy forest ecosystems, but little is known about their role in the aftermath of large-scale forest mortality caused by pest insect outbreaks. We used window traps to study short-term changes in the abundance and community structure of saproxylic beetles following extensive mortality of mountain birch in sub-arctic northern ...
    • Nutrients vs. turbulence, and the future of Arctic Ocean primary production 

      Randelhoff, Achim; Sundfjord, Arild; Fer, Ilker; Reigstad, Marit; Tremblay, Jean-Eric; Guthrie, John D. (Conference object; Konferansebidrag, 2016-11)
      This poster presents estimates of nitrate fluxes in the Arctic Ocean and speculates on the associated primary production in a future climate.
    • Nye frøblandingar for meir stabil grovfôrproduksjon 

      Østrem, Liv; Borchsenius, Ragnhild; Dalmannsdottir, Sigridur; Jørgensen, Marit; Kval‐Engstad, Oddbjørn; Lunnan, Tor (Research report; Forskningsrapport, 2021-04-23)
      Såvareverdikjeda i Norge er svært fragmentert samanlikna med land der same firma er ansvarleg for heile prosessen frå utvikling av ny sort til sal av frø. Dette forprosjektet har som mål å definera korleis ein gjennom meir forskningsbaserte frøblandingar og ferdig testa frøblandingar der bonden kan velja ut frå sine dyrkingsforhold og sin driftsmodell, kan auka avling og varighet av engvekstar. Dette ...