Sökning: "food web efficiency"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden food web efficiency.

  1. 1. Pelagic microorganisms in the northern Baltic Sea : Ecology, diversity and food web dynamics

    Författare :Johnny Berglund; Agneta Andersson; Ramon Massana; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; resource limitation; predation limitation; microbial food web; heterotrophic microorganisms; nanoflagellates; ciliates; protists; resource heterogeneity; chrysomonads; chrysophytes; group-specific PCR-DGGE primers; Baltic Sea; Marine ecology; Marin ekologi;

    Sammanfattning : Heterotrophic microorganisms are important for the flow of carbon and nutrients in the sea. Bacteria, nanoflagellates and ciliates are relevant components of the pelagic food web. In order to be able to predict the outcome of e.g. LÄS MER

  3. 2. Food web structures and carbon transfer efficiencies in a brackish water ecosystem

    Författare :Kristin Dahlgren; Ulf Båmstedt; Agneta Andersson; Marja Koski; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon transfer efficiency; Food web efficiency; zooplankton; production; pelagic; benthic; fatty acids; wax esters; Marine ecology; Marin ekologi;

    Sammanfattning : Two differently structured food webs can be distinguished in the pelagic habitat of aquatic systems; the classical one (autotrophic) with phytoplankton as a base and the microbial food web (heterotrophic) with bacteria as a base. Energy (produced at the basal trophic level) reaches higher trophic levels, i.e. LÄS MER

  4. 3. Effects of temperature and terrestrial carbon on fish growth and pelagic food web efficiency

    Författare :Robert Lefébure; Ulf Båmstedt; Pär Byström; Stefan Larsson; Agneta Andersson; Lars-Gösta Rudstam; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attack rates; Bacterial production; Climate change; Critical resource density; Growth rates; Microbial food web; Three-spined stickleback;

    Sammanfattning : Both temperature and terrestrial dissolved organic carbon (TDOC) have strong impacts on aquatic food web dynamics and production. Temperature affects vital rates of all organisms and terrestrial carbon has been shown to alter the dynamics of phytoplankton and bacterial production and affect the trophic structure of planktonic food webs. LÄS MER

  5. 4. 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. 5. The role of allelopathy in microbial food webs

    Författare :Astrid Weissbach; Catherine Legrand; Ellen Van Donk; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Microbial food web; Allelopathy; Alexandrium tamarense; Prymnesium parvum; Infochemicals; marine plankton community; Freshwater ecology; Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : Phytoplankton produce allelochemicals; excreted chemical substances that are affecting other microorganisms in their direct environment.In my thesis, I investigated strain specific variability in the expression of allelochemicals of the harmful flagellate Prymnesium parvum, that is euryhaline but mainly bloom forming in brackish water. LÄS MER