Sökning: "aquatic food web"

Visar resultat 6 - 10 av 54 avhandlingar innehållade orden aquatic food web.

  1. 6. Species interactions and energy transfer in aquatic food webs

    Författare :Jens Munk Nielsen; Monika Winder; Sture Hansson; Michael T. Brett; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aquatic food webs; zooplankton; stable isotope analysis amino acids; molecular diet analysis; Marine Ecology; marin ekologi;

    Sammanfattning : Food webs are structured by intricate nodes of species interactions which govern the flow of organic matter in natural systems. Despite being long recognized as a key component in ecology, estimation of food web functioning is still challenging due to the difficulty in accurately measuring species interactions within a food web. LÄS MER

  2. 7. Uptake Processes of Polychlorinated Biphenyls at the Base of the Pelagic Food Web

    Författare :Anna Sobek; Örjan Gustafsson; Derek Muir; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; PCBs; plankton; equilibrium partitioning; uptake; aquatic food web; Environmental chemistry; Miljökemi;

    Sammanfattning : Hydrophobic organic contaminants (HOCs) are persistent, toxic to biota and are known to bioaccumulate in food webs. In this thesis, polychlorinated biphenyls (PCBs) were used as model compounds to study the fate and transport of HOCs in the aquatic environment. LÄS MER

  3. 8. Consumption patterns and excretion in aquatic food websenrichment

    Författare :Anders Persson; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; trophic interactions; translocation; biomanipulation; enrichment; phosphorus; model; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : This thesis links biogeochemical cycling to classical ecology. Predictions derived from food chain theory, based on Lotka-Volterra type of interactions, were tested in aquatic environments with the main hypothesis that consumers affect lower levels of organization by both predation and excretion of limiting nutrients. LÄS MER

  4. 9. Climate-induced changes : Its effects on plankton food webs from the Baltic Sea

    Författare :Claudia Romero-Oliva; Edna Graneli; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate-induced changes; temperature; acidification; marine food web; natural plankton community; spring; summer; Baltic Sea; Marine ecology; Marin ekologi; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : The Earth’s climate is determined different processes occurring in the atmosphere, land and ocean.Anthropogenic activities (mainly combustion of fossil fuels) have increased since the 1950’s, andthus the concentration of greenhouse gases that are warming up the planet. LÄS MER

  5. 10. 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