Search for dissertations about: "periphyton"

Showing result 16 - 20 of 20 swedish dissertations containing the word periphyton.

  2. 16. The importance of predation in benthic stream communities

    Author : Jonas Dahl; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ekologi; Ecology; invertebrate predators; vertebrate predators; Predation; streams;

    Abstract : There has been considerable debate whether or not predators has any significant effects on prey densities in streams. This thesis examines the importance of predation in stream communities. I have conducted both field and laboratory studies where I have studied how both vertebrate and invertebrate predators affects benthic prey. READ MORE

  4. 17. Forest-stream linkages : Experimental studies of foraging and growth of brown trout (Salmo trutta L)

    Author : Pär Gustafsson; Eva Bergman; Larry Greenberg; John Armstrong; Karlstads universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Brown trout; diet; growth; riparian zone; forest-stream linkages; terrestrial invertebrates; light; primary production; Biology; Biologi; Biology; Biologi;

    Abstract : Riparian vegetation along streams and rivers affects the aquatic community in numerous ways and often operates as a link for energy flux between forest and streams. The studies presented in this licentiate thesis focus on light and terrestrial invertebrates, two factors influenced by riparian zone structure, which potentially affect stream ecosystems and thus also brown trout (Salmo trutta). READ MORE

  5. 18. Structuring factors for macroinvertebrate communities and the importance for ecosystem processing

    Author : Pia Hertonsson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; ephemeroptera; competition; Predation risk; brownification; invasive sp.; decomposition; grazing; growth; gastropoda; mortality; amphipoda; isopoda;

    Abstract : Aquatic macroinvertebrates play important roles in our ecosystems and are essential for the ecosystem processing. An improved knowledge of structuring factors, such as competition and predation, and the way in which they operates in the macroinvertebrate community is crucial for our understanding of not only the macroinvertebrates but also the ecosystem in general. READ MORE

  6. 19. 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. 20. Local and global contaminants in Swedish waters : studies on PCBs, DDTs, 4,5,6-trichloroguaiacol and their transformation products in fish and sediments

    Author : Maria Söderström; Åke Bergman; Bert van Bavel; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; PCB; DDT; HCB; trichloroguaiacol; transformation products; dimerisation; bromination; environmental pollutants; eutrophication; lakes; fresh water; baltic sea; monitoring; sediments; fish; phytoplankton; PCB; DDT; HCB; triklorguajakol; omvandlingsprodukter; dimerisering; bromering; miljöföroreningar; eutrofiering; sjöar; sötvatten; östersjön; miljöövervakning; sediment; fisk; fytoplankton; miljökemi; Environmental Chemistry;

    Abstract : This thesis is focused on studies on the environmental fate and methodological improvements for determination of the global contaminants, PCBs and DDTs, and locally discharged phenolics, e.g. 4,5,6-trichloroguaiacol (4,5,6-TCG), and their transformation products. READ MORE