Sökning: "aquatic ecology"
Visar resultat 21 - 25 av 197 avhandlingar innehållade orden aquatic ecology.
21. Links Between Structure and Function of Heterotrophic Aquatic Bacterial Communities
Sammanfattning : 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. LÄS MER
22. Thiamin (vitamin B1) in the aquatic food web
Sammanfattning : 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. LÄS MER
23. Interactions between Bacteria and Fungi on Aquatic Detritus – Causes and Consequences
Sammanfattning : 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. LÄS MER
24. 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
25. Psychotropic Pharmaceuticals in Aquatic Systems: An Ecological Perspective
Sammanfattning : 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. LÄS MER