Search for dissertations about: "predation"

Showing result 6 - 10 of 253 swedish dissertations containing the word predation.

  2. 6. Mechanisms structuring the pelagic microbial food web : Importance of resource and predation

    Author : Kristina Samuelsson; Agneta Andersson; Christiane Lancelot; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; pelagic microbial food web; bacteria; flagellates; ciliates; phytoplankton; mixotrophy; nutrient status; predation limitation; resource limitation; Baltic Sea; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : 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. READ MORE

  4. 7. Effects of Great Cormorant Predation on Fish Populations and Fishery

    Author : Henri Engström; Sture Hansson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Great Cormorant; Phalacrocorax carbo sinensis; predation; population regulation; diet; diet preferences; eel; behavioural responses; bird-fishery conflicts; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; populationsbiologi; Population Biology;

    Abstract : The strong increase in number of Great cormorants Phalacrocorax carbo in Sweden in recent years has led to conflicts - particularly with fishery. This thesis focuses on the possible effects of cormorant predation on fish populations. READ MORE

  5. 8. Predation on marine pelagic bacteria : On the in situ rates, regulation and dynamics of bacterivory studied with a molecular genetic technique

    Author : Johan Wikner; Åke Hagström; Caron David; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Marine; grazing; minicells; molecular genetics; method; predation rate; dynamics; bacterivore; predator-prey; mikrobiologi; Microbiology;

    Abstract : .... READ MORE

  6. 9. Species interactions in streams - effects of predation, competition and ecosystem properties

    Author : Erika Nilsson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; behaviour; species abundance; stable isotopes; habitat complexity; niche width; niche overlap; competition; streams; predation;

    Abstract : Stream ecosystems are dynamic and they have an inherent environmental variability. Organisms that live in streams are adapted to the continuously changing environment and the presence or absence of species are determined by their environmental requirements, while abundance is most often affected by interactions, such as competition and predation, with other species that are found in the same habitat. READ MORE

  7. 10. Multiple stressors in rotifer communities: : Effects of predation, climate change, and brownification

    Author : Huan Zhang; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Climate change; community dynamic; brownification; heat wave; inducible defense; rotifer; plasticity; multiple stressors; Predation; prey;

    Abstract : Most organisms on Earth live in an environment where they are exposed to multiple pressures, including predation and climate change. In many aquatic ecosystems, organisms have to handle additional challenges such as brownification, co-occurring with climate warming. READ MORE