Search for dissertations about: "Ekologi"

Showing result 21 - 25 of 1548 swedish dissertations containing the word Ekologi.

  2. 21. Chemical Communication and Mate Choice : Investigations into the Meaning of a Fruit Fly Pheromone

    Author : Björn G. Johansson; Göran Arnqvist; Fredrik Widemo; Anders Berglund; Allen Moore; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; Drosophila grimshawi; sexual selection; pheromone; mate choice; lekking; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : Chemical signals are the most widely used form of sexual communication throughout the living world. However, there is in general little knowledge about what these signals actually communicate. The role of chemical signals, i.e. READ MORE

  4. 22. Links Between Structure and Function of Heterotrophic Aquatic Bacterial Communities

    Author : Silke Langenheder; Lars Tranvik; Eva Lindström; David Kirchman; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; heterotrophic bacteria; dissolved organic matter; diversity; community composition; ecosystem functioning; salinity; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : Heterotrophic bacteria utilize dissolved organic matter, and the carbon flow through an ecosystem depends on the fractions of the utilized carbon that is either respired or transferred to higher trophic levels. The major aim this thesis is to investigate 1) the relationship between composition and functioning in heterotrophic bacterioplankton communities and 2) the influence of environmental conditions on both parameters. READ MORE

  5. 23. Interactions between Bacteria and Fungi on Aquatic Detritus – Causes and Consequences

    Author : Cecilia Mille-Lindblom; Lars Tranvik; Helmut Fischer; Eric Chauvet; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; bacteria; fungi; decomposition; antagonism; extracellular enzymes; competition; macrophytes; dissolved organic carbon DOC ; ergosterol; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

    Abstract : Bacteria and fungi dominate the decomposition of aquatic plants, a major process in the carbon and nutrient cycling in many aquatic systems. Although phylogenetically distant, bacteria and fungi often live in close proximity with each other. Since these microorganisms also have similar ecological functions, interactions have developed between them. READ MORE

  6. 24. Foraging behaviour in benthivorous fish

    Author : Marika Stenberg; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; resource assessment; giving-up densities; predation risk; foraging behaviour; limnology; marine biology; Ekologi; akvatisk ekologi; limnologi; group foraging; benthivorous fish; aquatic ecology; Hydrobiology; Ecology;

    Abstract : The foraging ability of an organism is essential since it affects various traits, e.g. growth, reproduction effort, social status and, ultimately, fitness. READ MORE

  7. 25. Direct and indirect effects of fish predation and excretion in aquatic food webs

    Author : José Luiz Attayde; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; Hydrobiology; zooplankton; resilience; predation; phytoplankton; nutrient enrichment; nutrient recycling; interaction strength; herbivory; food webs; food chain; excretion; fish; detritus; detritivory; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi; Ecology; Ekologi;

    Abstract : The aim of this thesis was to elucidate the mechanisms by which planktivorous fish can affect planktonic communities in lakes and how they may affect benthic communities through their effects on planktonic communities. In a laboratory experiment, nutrients released by fish increased algal biomass and altered phytoplankton community structure, suggesting that fish can affect phytoplankton by directly releasing nutrients. READ MORE