Sökning: "NATURVETENSKAP Biologi Terrestisk"

Visar resultat 1 - 5 av 107 avhandlingar innehållade orden NATURVETENSKAP Biologi Terrestisk.

  1. 1. Plant polyploidy and interactions with insect herbivores

    Författare :Leena Arvanitis; Johan Ehrlén; Christer Wiklund; John N. Thompson; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; diversicifation; herbivory; host plant preference; plant galls; plant-insect interactions; plant polyploidy; selection; spatial variation; trait-fitness relationship; Terrestrial ecology; Terrestisk ekologi; Plant Ecology; växtekologi;

    Sammanfattning : Polyploidization has been suggested to be a common mechanism for plant speciation. Polyploidy is associated with changes in plant traits and altered habitat preference. LÄS MER

  2. 2. Boreal vegetation responses to forestry as reflected in field trial and survey data and the quality of cover estimates and presence/absence in vegetation inventory

    Författare :Johan Bergstedt; Per Milberg; Göran Ståhl; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Boreal forest; cutting intensity; scarification; cover estimates; presence absence; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : Den här avhandlingen belyser hur avverkning och markberedning påverkar markfloran i den svenska barrskogen. Dessutom utvärderas två inventeringsmetoder som används inom växtekologin. LÄS MER

  3. 3. Non-target Effects of Genetically Modified Trees

    Författare :Patrik Blomberg; Anders Wennström; Jan Stenlid; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Genetically modified; GM trees; secondary metabolism; phytochemistry; Populus; transgenic; non-target effects; natural enemies; plant-pathogen herbivore interaction; environmental effects; parasitic fungi; herbivorous insect; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : To date, few studies have focused on the effects of genetically modified trees (GM trees) on the environment. One concern with GM trees is that they may have unanticipated effects on non-target organisms, i.e. effects on organisms that are not direct targets of the genetically modified trait. LÄS MER

  4. 4. The long-term decline of the grey-sided vole (Clethrionomys rufocanus) in boreal Sweden: importance of focal forest patch and matrix

    Författare :Pernilla Christensen; Birger Hörnfeldt; Rolf A. Ims; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; : Destructive sampling; high quality habitat; focal habitat; landscape; habitat fragmentation; threshold; clear-cut; patch size and quality; long-term time-series; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : There has been a long-term decline in number of cyclic vole populations in boreal Sweden since the 1970s. Several hypotheses have been suggested to explain this decline. Commonly for C. glareolus, C. LÄS MER

  5. 5. Interactions between gray-sided voles (Clethrionomys rufocanus) and vegetation in the Fennoscandian tundra

    Författare :Jonas Dahlgren; Lauri Oksanen; Johan Olofsson; John Terborgh; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; gray-sided voles; tundra vegetation; trophic cascades; plant-herbivore interactions; bilberry; plant communities; herbivory; plant resistance; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : I have, in this thesis, studied the interactions between gray-sided voles (Clethrionomys rufocanus) and tundra vegetation, on islands in, and mainland sites close to the lake Iešjávri, in northern Norway. As isolated islands are virtually free of predation, I have been able to compare plant-herbivore interactions in the presence and absence of predators. LÄS MER