• 175 years of adaptation: North Scandinavian Sámi reindeer herding between government policies and winter climate variability (1835–2010) 

      Riseth, Jan Åge; Tømmervik, Hans; Bjerke, Jarle W. (Journal article; Peer reviewed, 2016)
      Unmanaged wild reindeer populations tend to follow cyclical behaviour, and domesticatedreindeer populations often show cyclical behaviour, too. In this contribution, we intendto use the long-term development of two areas ...
    • Alpine garden plants from six continents show high vulnerability to ice encasement 

      Bjerke, Jarle W.; Elvebakk, Arve; Tømmervik, Hans (Journal article; Peer reviewed, 2017)
      Icy surfaces impose challenges for northern societies, wildlife and agriculture. However, there have been relatively few studies of the impacts of anoxic ground ice on non-agricultural plants. During the winter of 2009–2010, ...
    • Arctic greening from warming promotes declines in caribou populations 

      Fauchald, Per; Park, Taejin; Tømmervik, Hans; Myneni, Ranga B.; Hausner, Vera Helene (Journal article; Peer reviewed, 2017)
      Themigratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar ...
    • Biologisk mangfold. Bardu kommune 

      Strann, Karl Birger; Frivoll, Vigdis Irene; Iversen, Marianne; Tømmervik, Hans; Johnsen, Trond Vidar (NINA Rapport;58, Research report, 2005)
      Strann, K.-B., Frivoll, V., Iversen, M., Tømmervik, H. & Johnsen, T. 2005. Biologisk mangfold. Bardu kommune - NINA Rapport 58. 165 pp. Stortingsmelding nr. 42 (2000-2001) pålegger den enkelte sektor å gjennomføre ...
    • Changes in greening in the High Arctic - insights from a 30-year AVHRR max NDVI dataset for Svalbard 

      Vickers, Hannah; Høgda, Kjell Arild; Solbø, Stian; Karlsen, Stein Rune; Tømmervik, Hans; Aanes, Ronny; Hansen, Brage Bremset (Journal article; Peer reviewed, 2016)
      Satellite-aided studies of vegetation cover, biomass and productivity are becoming increasingly important formonitoring the effects of a changing climate on the biosphere. With their large spatial coverage and good temporal ...
    • Changes in growing season duration and productivity of northern vegetation inferred from long-term remote sensing data 

      Park, Taejin; Ganguly, Sangram; Tømmervik, Hans; Euskirchen, Eugénie S.; Høgda, Kjell Arild; Karlsen, Stein Rune; Brovkin, Victor; Nemani, Ramakrishna R.; Myneni, Ranga B. (Journal article; Peer reviewed, 2016)
      Monitoring and understanding climate-induced changes in the boreal and arctic vegetation is critical to aid in prognosticating their future.Weused a 33 year (1982–2014) long record of satellite observations to robustly ...
    • Changes in timing of seasonal peak photosynthetic activity in northern ecosystems 

      Park, Taejin; Chen, Chi; Macias-Fauria, Marc; Tømmervik, Hans; Choi, Sungho; Winkler, Alexander; Bhatt, Uma S.; Walker, Donald A.; Piao, Shilong; Brovkin, Victor; Nemani, Ramakrishna R.; Myneni, Ranga B. (Journal article; Peer reviewed, 2019)
      Seasonality in photosynthetic activity is a critical component of seasonal carbon, water and energy cycles in the Earth system. This characteristic is a consequence of plant’s adaptive evolutionary processes to a given set ...
    • Changes in winter warming events in the Nordic Arctic Region 

      Vikhamar-Schuler, Dagrun; Isaksen, Ketil; Haugen, Jan Erik; Tømmervik, Hans; Luks, Bartlomiej; Schuler, Thomas Vikhamar; Bjerke, Jarle W. (Journal article; Peer reviewed, 2016)
      In recent years extreme winter warming events have been reported in arctic areas. These events are characterized as extraordinarily warm weather episodes, occasionally combined with intense rainfall, causing ecological ...
    • China and India lead in greening of the world through land-use management 

      Chen, Chi; Park, Taejin; Wang, Xuhui; Piao, Shilong; Xu, Baodong; Chaturvedi, Rajiv K.; Fuchs, Richard; Brovkin, Victor; Ciais, Philippe; Fensholt, Rasmus; Tømmervik, Hans; Bala, Govindasamy; Zhu, Zaichun; Nemani, Ramakrishna R.; Myneni, Ranga B. (Journal article; Peer reviewed, 2019)
      Satellite data show increasing leaf area of vegetation due to direct factors (human land-use management) and indirect factors (such as climate change, CO2 fertilization, nitrogen deposition and recovery from natural ...
    • Distribution and population characteristics of the soil mites Diapterobates notatus and Svalbardia paludicola (Acari: Oribatida: Ceratozetidae) in High Arctic Svalbard (Norway) 

      Seniczak, Stanislaw; Seniczak, Anna; Graczyk, Radomir; Tømmervik, Hans; Coulson, Stephen James (Journal article; Peer reviewed, 2017)
      The Oribatida of High Arctic Svalbard are faunistically relatively well known, but the distribution, density, stage structure and other population parameters of most species are unknown. Here we focus on two ceratozetid ...
    • E6 Olsborg - Heia, delstrekning 3. Konsekvensanalyse for tema reindrift 

      Langeland, Knut; Danielsen, Inge Even; Tømmervik, Hans (NINA Rapport;1260, Research report, 2016-05-03)
      Langeland, Danielsen, Tømmervik. 2016. E6 Olsborg -Heia, delstrekning 3. Konsekvensanalyse for tema reindrift. NINA rapport 1260. 49 s. Statens vegvesen skal utarbeide reguleringsplan for utbedring av E6 fra Olsborg i ...
    • Ecosystem change and stability over multiple decades in the Swedish subarctic: complex processes and multiple drivers 

      Callaghan, Terry V.; Jonasson, Christer; Thierfelder, Tomas; Yang, Zhenlin; Hedenås, Henrik; Johansson, Margareta; Molau, Ulf; Van Bogaert, Rik; Michelsen, Anders; Olofsson, Johan; Gwynn-Jones, Dylan; Bokhorst, Stef; Phoenix, Gareth K.; Bjerke, Jarle Werner; Tømmervik, Hans; Christensen, Torben R.; Hanna, Edward; Koller, Eva K.; Sloan, Victoria L. (Journal article; Peer reviewed, 2013)
      The subarctic environment of northernmost Sweden has changed over the past century, particularly elements of climate and cryosphere. This paper presents a unique geo-referenced record of environmental and ecosystem ...
    • Ecosystem response to climatic change: the importance of the cold season 

      Bokhorst, Stef; Bjerke, Jarle Werner; Tømmervik, Hans; Preece, Catherine; Phoenix, Gareth K. (Journal article; Peer reviewed, 2012)
      Winter climate and snow cover are the important drivers of plant community development in polar regions. However, the impacts of changing winter climate and associated changes in snow regime have received much less attention ...
    • Feasibility of hyperspectral vegetation indices for the detection of chlorophyll concentration in three high Arctic plants: Salix polaris, Bistorta vivipara, and Dryas octopetala 

      Zagajewski, Bogdan; Kycko, Marlena; Tømmervik, Hans; Bochenek, Zbigniew; Wojtun, Bronislaw; Bjerke, Jarle W.; Klos, Andrzej (Peer reviewed, 2018)
      Remote sensing, which is based on a reflected electromagnetic spectrum, offers a wide range of research methods. It allows for the identification of plant properties, e.g., chlorophyll, but a registered signal not only ...
    • Forsøk med forsterkning og revegetering av kjøretraséer i Porsangmoen - Hálkavárri skytefelt 

      Tømmervik, Hans; Bakkestuen, Vegar; Erikstad, Lars (NINA Rapport;341, Research report, 2008)
      Tømmervik, H., Bakkestuen, V. og Erikstad, L. 2008. Forsøk med forsterkning og revegetering av kjøretraséer i Porsangmoen - Hálkavárri skytefelt. NINA Rapport 341, 35 s. Rapporten oppsummerer forsøk gjort med forsterkning ...
    • Future forest distribution on Finnmarksvidda, North Norway 

      Karlsen, Stein Rune; Tømmervik, Hans; Johansen, Bernt; Riseth, Jan Åge (Journal article; Peer reviewed, 2017)
      Finnmarksvidda is Norway’s largest mountain plateau, located in the Arctic/alpineboreal transition area. The area is also a central winter grazing area for the reindeer herds of the indigenous Sámi people. This study ...
    • High tolerance of a high-arctic willow and graminoid to simulated ice encasement 

      Bjerke, Jarle W.; Elverland, Ellen; Jaakola, Laura; Lund, Leidulf; Zagajewski, Bogdan; Bochenek, Zbigniew; Kłos, Andrzej; Tømmervik, Hans (Journal article; Peer reviewed, 2018)
      Climate change-induced snow thaw and subsequent accumulation of ice on the ground is a potential, major threat to snow-dominated ecosystems. While impacts of ground-ice on arctic wildlife are well explored, the impacts on ...
    • Historiske tamreintall i Norge fra 1800-tallet fram til i dag 

      Tømmervik, Hans; Riseth, Jan Åge (NINA rapport, Research report, 2011)
      Tømmervik, H. & Riseth, J. Å. 2011. Historiske tamreintall i Norge fra 1800-tallet fram til i dag - NINA Rapport 672. 36 s. På oppdrag for Direktoratet for naturforvaltning har vi sammenstilt tilgjengelige data for ...
    • Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing 

      Bokhorst, Stef; Berg, atty P.; Edvinsen, Guri K.; Ellers, Jacintha; Heitman, Amber; Jaakola, Laura; Mæhre, Hanne K.; Phoenix, Gareth K.; Tømmervik, Hans; Bjerke, Jarle W. (Peer reviewed, 2018)
      Climate change is one of many ongoing human-induced environmental changes, but few studies consider interactive effects between multiple anthropogenic disturbances. In coastal sub-arctic heathland, we quantified the ...
    • Impacts of snow season on ground-ice accumulation, soil frost andprimary productivity in a grassland of sub-Arctic Norway 

      Bjerke, Jarle W.; Tømmervik, Hans; Zielke, Matthias; Jørgensen, Marit (Peer reviewed, 2015)
      Europe’s and the World’s northernmost agriculture is very vulnerable to harsh overwintering conditions. It is important from both an economic and societal standpoint to have accurate methods of predicting the severity ...