Sökning: "food web structure"
Visar resultat 6 - 10 av 56 avhandlingar innehållade orden food web structure.
6. Mysid growth, stable isotope fractionation, and energetics : implications for food web studies
Sammanfattning : Field data, stable isotope analyses of the Baltic Sea food web structure,and experimental studies of the functional response indicate that theomnivorous crustacean Mysis mixta (Crustacea, Mysidacea) has no distinct trophic position, but can potentially affect plankton communitystructure and compete with herring and sprat for the zooplankton. Toevaluate field data on mysid body constituents, abundance and populationstructure, and that of their potentialprey, basic knowledge of feeding behaviour, growth mechanisms, andreproductive capabilities are required. LÄS MER
7. Mechanisms structuring the pelagic microbial food web : Importance of resource and predation
Sammanfattning : Temporal and spatial variations of pelagic microorganisms in the northern Baltic Sea were studied, as well as factors influencing their abundance and growth rates. Three main questions were asked 1) How does increased productivity influence the structure of the microbial food web? 2) Does predation limitation vary between trophic levels? 3) What is the relative importance of resource and predation limitation at different trophic levels?A field study in the northern Baltic Sea showed that dominating protozoa, flagellates and ciliates, increased with increasing primary productivity from north to south. LÄS MER
8. Benthic invertebrate food webs in the Baltic Sea : Anthropogenic pressure effects and methodological advancements
Sammanfattning : Trophic interactions are ecologically important, as they structure communities, and globally important for the ecosystem functions that they facilitate. Anthropogenic pressures are altering the structure of food webs, their stability, and resilience to change. LÄS MER
9. Food web structures and carbon transfer efficiencies in a brackish water ecosystem
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
10. Effects of temperature and terrestrial carbon on fish growth and pelagic food web efficiency
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
