Sökning: "limnology"
Visar resultat 16 - 20 av 94 avhandlingar innehållade ordet limnology.
16. Effects of inorganic nitrogen and organic carbon on pelagic food webs in boreal lakes
Sammanfattning : Anthropogenic activities are increasing inorganic nitrogen (N) loadings to lakes in the northern hemisphere. In many boreal lakes phytoplankton are N limited, wherefore enhanced N input may affect the productivity of pelagic food webs. LÄS MER
17. Solar radiation effects on decomposition and decomposers of plant litter in lakes
Sammanfattning : This thesis summarizes the results of a series of experiments, from test tube up to field study scale, performed to increase the understanding of solar radiation effects on decomposition and microbial decomposers of plant litter in stagnant water of littoral zones. In conclusion, I suggest that fungi play a significant role in the decomposition of plant litter submersed in lakes, and that their distribution is dependent on detritus quality and water chemistry, but also tends to be inversely related to the occurrence of bacteria attached to the litter. LÄS MER
18. The Role of Picophytoplankton in Lake Food Webs
Sammanfattning : Picophytoplankton were inferior competitors for inorganic phosphorus compared to heterotrophic bacteria. This may be due to the source of energy available for the heterotrophs, while cell-size was of minor importance. However, picophytoplankton were superior to large phytoplankton in the competition for nutrients at low concentrations. LÄS MER
19. Phytoplankton and bacterioplankton dynamics in a polymictic tropical lake
Sammanfattning : Phytoplankton and bacterioplankton dynamics in lakes are regulated by a multitude of factors such as light, temperature, water column mixing, nutrients, organic substrates, grazing, and food web structure. Tropical lakes are especially interesting to study because of the relative constancy of several of these factors. LÄS MER
20. Regulation and role of epiphytic nitrification and denitrification in macrophyte-dominated systems
Sammanfattning : This thesis examines mechanisms regulating bacterial nitrification and denitrification in attached microbial communities on surfaces of aquatic macrophytes. It also evaluates the role of epiphytic nitrification and denitrification for the nitrogen turnover in macrophyte-dominated nutrient-rich freshwaters. LÄS MER