Sökning: "grazer"

Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet grazer.

  1. 1. Nutrient Stoichiometry in Benthic Food Webs – Interactions Between Algae, Herbivores and Fish

    Författare :Antonia Liess; Peter Eklöv; Dag Hessen; Uppsala universitet; []
    Nyckelord :Ecology; ecologial stoichiometry; periphyton; grazer; benthos; trophic interactions; nutrient; algae; Ekologi;

    Sammanfattning : The aim of this thesis was to identify general structuring mechanisms in benthic food webs within the framework of ecological stoichiometry theory. Ecological stoichiometry is defined as the balance of multiple chemical substances in ecological interactions and explicitly considers the combined dynamics of key elements such as carbon (C), nitrogen (N) and phosphorus (P). LÄS MER

  3. 2. The role of herbivores in mediating responses of tundra ecosystems to climate change

    Författare :Elina Kaarlejärvi; Johan Olofsson; Anu Eskelinen; Jon Moen; Eric Post; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate change; warming; grazer; Rangifer; Lemmus lemmus; species distribution; biotic interactions; altitude; Environmental Science; miljövetenskap;

    Sammanfattning : The Arctic areas are warming more rapidly than other parts of the world. Increasing temperatures are predicted to result in shrubification, higher productivity, declining species diversity and new species invasions to the tundra. LÄS MER

  4. 3. Biomass and Nutrient Status of Benthic Algae in Lakes

    Författare :Maria Kahlert; Alan Steinman; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; benthic algae; patchiness; C:N:P ratio; nutrient recycling; grazer; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; limnologi; Limnology;

    Sammanfattning : For a complete picture of the lake ecosystem, it is necessary to understand the mechanisms regulating biomass and nutrient status (nutrient limitation, optimal supply, or surplus) of benthic algae, which are important primary producers and a food resource for grazers. This thesis gives an overview of the natural variation of benthic algae at different scales of space and time and on different substrates, and unravels some of the underlying factors. LÄS MER

  5. 4. Grazer-induced responses in marine phytoplankton

    Författare :Johanna Bergkvist; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; defence; dinoflagellate; diatoms; paralytic shellfish toxins; polyunsaturated aldehydes; chain formation;

    Sammanfattning : Phytoplankton are the most important primary producers in the world’s oceans, yet little is known of how they avoid the constant threats from the pelagic grazers. From land it is well known that plants defend themselves by having thorns or producing compounds unpalatable to grazers. LÄS MER

  7. 5. Phytoplankton defense mechanisms against grazing : the role of grazing infochemicals

    Författare :Veronica Lundgren; Edna Granéli; Takeshi Yasumoto; Aaron Barkoh; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : Many phytoplankton species have evolved a variety of different defenses to decrease losses from grazing; morphological features, changes in life-history/behavior, and production of toxins. These defenses may be associated with costs. Therefore, some phytoplankton only express the defense when needed, i.e. LÄS MER