Blar i NTNU Open på forfatter "van der Wal, René"

Viser treff 1-12 av 12

    • A new NDVI measure that overcomes data sparsity in cloud-covered regions predicts annual variation in ground-based estimates of high arctic plant productivity 

      Karlsen, Stein Rune; Anderson, Helen B.; van der Wal, René; Hansen, Brage Bremset (Journal article; Peer reviewed, 2018)
      Efforts to estimate plant productivity using satellite data can be frustrated by the presence of cloud cover. We developed a new method to overcome this problem, focussing on the high-arctic archipelago of Svalbard where ...

    • Annual ring growth of a widespread high arctic shrub reflects past fluctuations in community‐level plant biomass 

      Le Moullec, Mathilde; Buchwal, Agata; van der Wal, René; Sandal, Lisa; Hansen, Brage Bremset (Journal article; Peer reviewed, 2018)
      1. Long time series of primary production are rarely available, restricting our mechanistic understanding of vegetation and ecosystem dynamics under climate change. Dendrochronological tools are increasingly used instead, ...

    • Biding time before breeding: flexible use of the Arctic landscape by migratory geese during spring 

      Anderson, Helen; Hübner, Christiane E.; Speed, James David Mervyn; Madsen, Jesper; van der Wal, René (Journal article; Peer reviewed, 2015)
      Many millions of long-distance migrants use pre-breeding staging sites located adjacent to breeding grounds immediately prior to nesting, presumably to improve body condition and thus reproductive success. However, in ...

    • Combination of herbivore removal and nitrogen deposition increases upland carbon storage 

      Smith, Stuart; Johnson, David; Quin LO, Samuel; Munro, Kyle; Pakeman, Robin J; van der Wal, René; Woodin, Sarah J. (Journal article; Peer reviewed, 2015)
      Ecosystem carbon (C) accrual and storage can be enhanced by removing large herbivores as well as by the fertilizing effect of atmospheric nitrogen (N) deposition. These drivers are unlikely to operate independently, yet ...

    • Contrasting effects of summer and winter warming onbody mass explain population dynamics in a food-limitedArctic herbivore 

      Albon, Steve D.; Irvine, R. Justin; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif Egil; Ropstad, Erik; Veiberg, Vebjørn; van der Wal, René; Bjørkvoll, Eirin Marie; Duff, Elizabeth I.; Hansen, Brage Bremset; Lee, Aline Magdalena; Tveraa, Torkild; Stien, Audun (Journal article; Peer reviewed, 2016)
      The cumulative effects of climate warming on herbivore vital rates and population dynamics are hard to predict, given that the expected effects differ between seasons. In the Arctic, warmer summers enhance plant growth ...

    • Experimental icing affects growth, mortality, and flowering in a high Arctic dwarf shrub 

      Milner, Jos M; Varpe, Øystein; van der Wal, René; Hansen, Brage Bremset (Peer reviewed; Journal article, 2016)
      Effects of climate change are predicted to be greatest at high latitudes, with more pronounced warming in winter than summer. Extreme mid-winter warm spells and heavy rain-on-snow events are already increasing in frequency ...

    • Growth rings show limited evidence for ungulates’ potential to suppress shrubs across the Arctic 

      Vuorinen, Katariina Elsa Maria; Austrheim, Gunnar; Tremblay, Jean-Pierre; Myers-Smith, Isla H.; Hortman, Hans Ivar; Frank, Peter; Barrio, Isabel C.; Dalerum, Fredrik; Björkman, Mats Peter; Björk, Robert G.; Ehrich, Dorothee; Sokolov, Aleksandr; Sokolova, Natalya; Ropars, Pascale; Boudreau, Stephane; Normand, Signe; Prendin, Angela L.; Schmidt, Niels Martin; Pacheco-Solana, Arturo; Post, Eric; John, Christian; Kerby, Jeff; Sullivan, Patrick F.; Le Moullec, Mathilde; Hansen, Brage Bremset; van der Wal, René; Pedersen, Åshild Ønvik; Sandal, Lisa; Gough, Laura; Young, Amanda; Li, Bingxi; Magnusson, Runa I.; Sass-Klaassen, Ute; Buchwal, Agata; Welker, Jeffrey; Grogan, Paul; Andruko, Rhett; Morrissette-Boileau, Clara; Volkovitskiy, Alexander; Terekhina, Alexandra; Speed, James David Mervyn (Peer reviewed; Journal article, 2022)
      Global warming has pronounced effects on tundra vegetation, and rising mean temperatures increase plant growth potential across the Arctic biome. Herbivores may counteract the warming impacts by reducing plant growth, but ...

    • Highways up the mountains: Trails as facilitators for redistribution of plant species in mountain areas. 

      Wedegärtner, Ronja E. M. (Doctoral theses at NTNU;2022:293, Doctoral thesis, 2022)
      To protect mountain ecosystems, their biodiversity, ecosystem services, and other contributions to people, it is necessary to understand how climate and disturbances affect them. Trails may change seed dispersal and disrupt ...

    • Hiking trails shift plant species' realized climatic niches and locally increase species richness 

      Wedegärtner, Ronja Elisabeth Magdalene; Lembrechts, Jonas J.; van der Wal, René; Barros, Agustina; Chauvin, Aurélie; Janssens, Ilias; Graae, Bente Jessen (Peer reviewed; Journal article, 2022)
      Aim The presence and use of trails may change plant species' realized climatic niches via modified abiotic and biotic conditions including propagule transport, allowing competition-pressed alpine species to expand their ...

    • Milling plant and soil material in plastic tubes over-estimates carbon and under-estimates nitrogen concentrations 

      Smith, Stuart; Robertson, A H Jean; Meharg, Andrew A; Pakeman, Robin J; Johnson, David; Woodin, Sarah J.; van der Wal, René (Journal article, 2013)
      Background and aims Milling of plant and soil material in plastic tubes, such as microcentrifuge tubes, over-estimates carbon (C) and under-estimates nitrogen (N) concentrations due to the introduction of polypropylene ...

    • Optimizing carbon storage within a spatially heterogeneous upland grassland through sheep grazing management 

      Smith, Stuart; Vandenberghe, Charlotte; Hastings, Ashley; Johnson, David; Pakeman, Robin J; van der Wal, René; Woodin, Sarah J. (Journal article; Peer reviewed, 2014)
      Livestock grazing is known to influence carbon (C) storage in vegetation and soil. Yet, for grazing management to be used to optimize C storage, large scale investigations that take into account the typically heterogeneous ...

    • Root traits predict decomposition across a landscape-scale grazing experiment 

      Smith, Stuart; Woodin, Sarah J.; Pakeman, Robin J; Johnson, David; van der Wal, René (Journal article; Peer reviewed, 2014)
      - Root litter is the dominant soil carbon and nutrient input in many ecosystems, yet few studies have considered how root decomposition is regulated at the landscape scale and how this is mediated by land‐use management ...