Sökning: "arctic and alpine vegetation"

Hittade 5 avhandlingar innehållade orden arctic and alpine vegetation.

  1. 1. Effects of herbivory on arctic and alpine vegetation

    Författare :Åsa Lindgren; Ove Eriksson; Jon Moen; Anders Angerbjörn; Ingibjörg S Jónsdóttir; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; herbivory; reindeer; rodents; functional traits; plant species composition; arctic; alpine; tundra; seed limitation; Carex bigelowii; Biology; Biologi; Plant Ecology; växtekologi;

    Sammanfattning : The distribution of plant species and functional traits in alpine and arctic environments are determined by abiotic conditions, but also by biotic interactions. In this thesis, I investigate interactions among plants and herbivory effects on plant community composition and plant functional traits in three different regions: Swedish Lapland, Beringia (USA/Russia) and Finnmark (Norway). LÄS MER

  2. 2. Mosses as mediators of climate change : implications for tree seedling establishment in the tundra

    Författare :Signe Lett; Ellen Dorrepaal; David Wardle; Marie-Charlotte Nilsson; Vigdis Vandvik; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; arctic; alpine; B. pubescens; bryophytes; competition; facilitation; mosses; P. sylvestris; precipitation changes; seedlings; traits; tree line; warming;

    Sammanfattning : Alpine and arctic tree line expansion depends on the establishment of tree seedlings above the current tree line, which is expected to occur with climate warming. However, tree lines often fail to respond to higher temperatures. Other environmental factors are therefore likely important for tree seedling establishment. LÄS MER

  3. 3. The zoo-geomorphological impact of fossorial rodents in sub-polar alpine environments

    Författare :Bert Eriksson; Jan Boelhowers; John Östh; Hanna Ridefelt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zoo-geomorphology; fossorial rodents; sub-polar; alpine; geomorphic work; ecosystem engineers; Physical geography; Naturgeografi; Geography; Geografi;

    Sammanfattning : The geomorphological impact of small fossorial mammals (adapted to digging and living underground), such as rodents can be significant, and both their direct and indirect effects may contribute to landscape formation. This thesis is based on empirical field studies of two burrowing rodent species in sub-polar environments, namely invasive House mice (Mus musculus) on sub-Antarctic Marion Island and Norwegian lemmings (Lemmus lemmus) in sub-Arctic Abisko. LÄS MER

  4. 4. 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

  5. 5. Mountain vegetation in the Faroe Islands in a climate change perspective

    Författare :Anna Maria Fosaa; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; klimatologi; marklära; Växtekologi; Fysisk geografi; climatology; cartography; pedology; geomorphology; climate change.; Physical geography; Raunkiær´s life-forms; biodiversity; Vegetation zones; plant communities; Plant ecology; kartografi; geomorfologi;

    Sammanfattning : This thesis is a study of the mountain vegetation in the Faroe Islands based on five altitudinal transects sampled during the period 1999-2001. The vegetation was studied on the basis of plant communities, life-forms and biodiversity of vascular plant species and is discussed in a climate change perspective. LÄS MER