Sökning: "Enhet Akvatisk Ekologi"
Visar resultat 1 - 5 av 32 avhandlingar innehållade orden Enhet Akvatisk Ekologi.
1. Predator-prey interactions in freshwater systems: The importance of chemical communication
Sammanfattning : Predator released chemical cues provide a valuable source of information to prey organisms that can be used to alter their behaviour in order to reduce predation risk. In this thesis, I have examined under what circumstances chemical cues may be used by prey, and if prey discriminate between different cues. LÄS MER
2. Allochthonous and autochthonous carbon sources of lake bacterioplankton
Sammanfattning : Organic substrates for pelagic bacteria are derived from dissolved organic carbon (DOC) in the water column that originates either from primary production from within the lake itself (autochthonous), or import of organic matter from the terrestrial watershed (allochthonous production). This thesis addresses the utilization of allochthonous versus autochthonous carbon (C) sources by lake bacterioplankton. LÄS MER
3. Drivers of increasing iron concentrations in 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
4. The significance of sexuality and cyst formation in the life-cycles of four marine dinoflagellate species
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
5. Consumption patterns and excretion in aquatic food websenrichment
Sammanfattning : 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. LÄS MER
