Search for dissertations about: "aquatic ecology"

Showing result 21 - 25 of 198 swedish dissertations containing the words aquatic ecology.

  2. 21. 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

  4. 22. Thiamin (vitamin B1) in the aquatic food web

    Author : Emil Fridolfsson; Samuel Hylander; Michael T. Brett; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; zooplankton; thiamin; transfer; food web dynamics; micronutrient; vitamin; Baltic Sea; community composition; M74; salmon; B1; växtplankton; djurplankton; tiamin; överföring; födoväv; mikronäringsämne; vitamin; Östersjön; B1; lax; Ecology; Ekologi;

    Abstract : Thiamin (vitamin B1) is required for several life-sustaining processes in most organisms and cells, e.g. in the conversion of food to energy. It also serves as an antioxidant and is important for proper nerve signaling. 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. Consumption patterns and excretion in aquatic food websenrichment

    Author : Anders Persson; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Hydrobiology; trophic interactions; translocation; biomanipulation; enrichment; phosphorus; model; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : This thesis links biogeochemical cycling to classical ecology. Predictions derived from food chain theory, based on Lotka-Volterra type of interactions, were tested in aquatic environments with the main hypothesis that consumers affect lower levels of organization by both predation and excretion of limiting nutrients. READ MORE

  7. 25. Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective

    Author : Melanie Hedgespeth; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ecotoxicology; aquatic; trophic level; pharmaceutical; SSRI; beta-blocker; sertraline; fluoxetine; propranolol; fish; daphnia; snail; predator; prey; behavior; life history; multiple stressor;

    Abstract : Psychotropic pharmaceuticals have been shown to exert a variety of sublethal effects on non-target organisms, even at low concentrations found in the environment (ng/L to µg/L); hence, the aim of my research has been to determine the individual-level effects of psychotropic pharmaceuticals (the selective serotonin reuptake inhibitors sertraline and fluoxetine, and the β-blocker propranolol) on behavioral and life history traits in freshwater organisms. Further, this research was directed towards assessing the potential large-scale impacts of these effects on population growth and predator-prey interactions (with community-level implications) via the application of traditional, ecological concepts and models. READ MORE