Sökning: "Akvatisk ekologi"

Visar resultat 11 - 15 av 98 avhandlingar innehållade orden Akvatisk ekologi.

  1. 11. Ecotoxicological assessment by microcosm tests on plankton communities

    Författare :Pardis Pirzadeh; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; aquatic ecology; limnology; Ecology; Ekologi; Hydrobiology; marine biology; musk substances; brominated flame retardants; structural effects; akvatisk ekologi; Environmental chemistry; Miljökemi; mesocosm;

    Sammanfattning : The aim of this thesis is to present a short-term plankton community toxicity test in laboratory microcosms, with which the effect of the test substance on species abundance and composition of the community is evaluated. This laboratory microcosm is an intermediate between single-species tests and outdoor mesocosm tests. LÄS MER

  3. 12. The role of young-of-the-year fish in lake ecosystems

    Författare :Pia Romare; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; Rutilus rutilus; Perca fluviatilis; diet-dependent growth; density dependent growth; behavioural cascade; 0 fish behaviour; horizontal echo sounding; biomanipulation; trophic cascade; predation pressure; young-of-the-year fish; trophic interactions; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

    Sammanfattning : Food chain theory is based on consumption; that is, presupposing that the only important interaction between organisms is that they actually meet in an unstructured environment and that one of them is consumed. Recently, studies, including biomanipulation projects, have indicated that trophic interactions are more complex than predicted by food chain theory. LÄS MER

  4. 13. Internal oxygen transport to below-ground parts: importance for emergent macrophytes

    Författare :Viveka Vretare Strand; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; water depth; zonation; phenotypic plasticity; biomass allocation; pressurised ventilation; oxygen; Phragmites australis; emergent macrophytes; common reed; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

    Sammanfattning : This thesis examines factors regulating growth and distribution of emergent plants with focus on effects of oxygen supply to the roots. Greenhouse experiments revealed that P. australis acclimatizes to specific water depths with phenotypic plasticity. LÄS MER

  5. 14. Drivers of increasing iron concentrations in freshwaters

    Författare :Caroline Björnerås; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Järn; Akvatisk ekologi; Biogeokemi; Brunifiering; Iron; Freshwaters; Biogeochemistry; Brownification; Iron biogeochemistry; Browning; Freshwaters;

    Sammanfattning : Iron (Fe) concentrations are increasing in freshwaters (lakes and streams) in Sweden, as well as in other regions in northern Europe. Together with increasing concentrations of organic matter, Fe is contributing to the ongoing browning of freshwaters, which may have serious ecological consequences and implications for ecosystem services. LÄS MER

  7. 15. The significance of sexuality and cyst formation in the life-cycles of four marine dinoflagellate species

    Författare :Rosa Figueroa; Enhet akvatisk ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cyst; Hydrobiology; akvatisk ekologi; marine biology; aquatic ecology; limnology; sexuality.; meiosis; Lingulodinium polyedrum; life-cyle; limnologi; Marinbiologi; Gymnodinium nolleri; Gymnodinium catenatum; Alexandrium catenella; dinoflagellates;

    Sammanfattning : Sexuality and cyst formation were studied in the marine dinoflagellate species Gymnodinium catenatum Graham, Gymnodinium nolleri Ellegaard ? Moestrup, Alexandrium catenella (Whedon et Kofoid) Balech, and Lingulodinium polyedrum (Stein) Dodge. The study included the morphological characterization of sexual stages and processes, the time and description of meiosis, the study of the length and regulation of the mandatory dormancy period of resting cysts, and the relationships among parental strains and cyst progeny at phenotypic and molecular levels. LÄS MER