Sökning: "subarctic"

Visar resultat 26 - 30 av 75 avhandlingar innehållade ordet subarctic.

  1. 26. The Torneträsk System - A basis for predicting future subarctic ecosystems

    Författare :Didac Pascual; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; climate change; carbon fluxes; ecosystem change; climate projections; rain on snow; modelling; impacts; snow; permafrost; winter warming events;

    Sammanfattning : Arctic and subarctic areas have experienced a rapid warming and substantial increases in precipitation in recent decades. The frequency and intensity of some extreme events, such as fires, winter warming events, extreme rainfall, and droughts, has also increased. LÄS MER

  3. 27. Spatial and temporal dynamics of subarctic birch forest carbon exchange

    Författare :Michal Heliasz; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mountain birch; eddy covariance; carbon budget; insect outbreak; forest expansion; temporal variability; spatial variability;

    Sammanfattning : High northern latitudes are of special importance for the global carbon budget as they store large amounts of organic matter in the soil and are expected to be the most strongly affected by climate change. Here we investigate carbon exchange in the subarctic mountain birch forest growing on the limit where tree growth is possible. LÄS MER

  4. 28. Hemiparasites in the Subarctic: Resource acquisition, growth and population dynamics

    Författare :Carin H Nilsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; population dynamics; selectivity; Phenotypic plasticity; fitness; Plant ecology; Växtekologi;

    Sammanfattning : Parasitic plants are found in nearly every major terrestrial ecosystem and can be divided into two groups, holoparasites (lacking chlorophyll) and hemiparasites (chlorophyllous). The host-parasite connection is either situated above (stem parasites) or below ground (root parasites). LÄS MER

  5. 29. Supply and metabolism of nitrogen and phosphorus in subarctic lakes : experiments in the Kuokkel area, northern Sweden

    Författare :Mats Jansson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  7. 30. Herbivory and plant community structure in a subarctic altitudinal gradient

    Författare :Jon Moen; Nancy Huntly; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; arctic and alpine vegetation; competition; exclosures; lemmings; plant defences; plant-plant interactions; Ranunculus glacialis; snow-bed; structuring factors; tall herb meadow; vertebrate grazing; voles;

    Sammanfattning : The object of this thesis was to study plant community structure, especially in relation to vertebrate herbivory, in an altitudinal gradient in the Fennoscandian mountain chain.A sowing experiment in a high alpine Ranunculus glacialis population showed that seeds germinated better in cleared microsites than under established individuals. LÄS MER