Sökning: "phytoplankton composition"

Visar resultat 11 - 15 av 65 avhandlingar innehållade orden phytoplankton composition.

  1. 11. Chemical composition of summertime High Arctic aerosols

    Författare :Karolina Siegel; Claudia Mohr; Annica Ekman; Ilona Riipinen; Lise Lotte Sørensen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aerosol; chemical composition; Arctic climate; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : This thesis presents new insights into the chemical composition of semi-volatile compounds in aerosol samples collected in the central Arctic Ocean close to the North Pole in September 2018. The central Arctic Ocean is an inaccessible location due to the lack of land areas along with heavy pack ice conditions. LÄS MER

  3. 12. Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem : Bottom-up effects in an aquatic food web

    Författare :Norbert Häubner; Pauli Snoeijs; Jon Ågren; Rhena Schumann; Markku Viitasalo; Uppsala universitet; []
    Nyckelord :Baltic Sea; carotenoids; astaxanthin; tocopherols; Vitamin E; thiamine; Vitamin B1; pelagic food web; eutrophication; M74; phytoplankton; zooplankton; sprat; Sprattus sprattus balticus; herring; Clupea harengus; salmon; Salmo salar; cod; Gadus morhua; High Performance Liquid Chromatography HPLC ; electrochemical detection ECD ;

    Sammanfattning : The thesis combines laboratory experiments and field expeditions to study production, transfer and consumption of non-enzymatic antioxidants and thiamine in an aquatic food web. In particular, I (1) documented spatial and seasonal variation of tocopherols and carotenoids in the Baltic Sea pelagic food web, and (2) examined the effects of abiotic and biotic factors on tocopherol, carotenoid and thiamine concentrations in phytoplankton, zooplankton and fish. LÄS MER

  4. 13. Phenotypic and Genotypic responses in the planktonic diatom Skeletonema marinoi - Effects of Natural Processes and Anthropogenic Stressors

    Författare :Susanna Gross; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diatoms; genotype; phenotype; resting cell; eutrophication; spring bloom; diversity; grazing; adaptation; phytoplankton; microalgae; Skeletonema;

    Sammanfattning : Diatoms are one of the most diverse and abundant phytoplankton taxa and are highly important as primary producers, accounting for nearly half of the marine primary production and constituting the base in the marine food web. Despite their high dispersal potential they are genetically diverse and display genetically structured populations. LÄS MER

  5. 14. Effects of inorganic nitrogen and organic carbon on pelagic food webs in boreal lakes

    Författare :Anne Deininger; Ann-Kristin Bergström; Jan Karlsson; Antonia Liess; Carolyn L. Faithfull; John A. Downing; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; autochthony; basal production; boreal; global change; dissolved organic carbon; food web efficiency; N deposition; phytoplankton; seston stoichiometry; whole lake enrichment; zooplankton; limnologi; Limnology;

    Sammanfattning : Anthropogenic activities are increasing inorganic nitrogen (N) loadings to lakes in the northern hemisphere. In many boreal lakes phytoplankton are N limited, wherefore enhanced N input may affect the productivity of pelagic food webs. LÄS MER

  7. 15. Ecology of zooplankton communities: climate, dormancy, and benthic-pelagic coupling

    Författare :Mikael Gyllström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnologi; akvatisk ekologi; limnology; Hydrobiology; marine biology; aquatic ecology; phytoplankton; temporal stability; recruitment; seasonal succession; environmental cues; diapause; shallow lakes; predation; enrichment; climate; temperature;

    Sammanfattning : This thesis describes how influences, such as top down and bottom up forces, shape zooplankton communities in shallow lakes. I have also extended the traditional food-web theory by investigating the effects of climate on total biomass, taxonomic composition, and temporal properties of zooplankton communities. LÄS MER