Search for dissertations about: "limnology"

Showing result 16 - 20 of 94 swedish dissertations containing the word limnology.

  2. 16. Effects of inorganic nitrogen and organic carbon on pelagic food webs in boreal lakes

    Author : Anne Deininger; Ann-Kristin Bergström; Jan Karlsson; Antonia Liess; Carolyn L. Faithfull; John A. Downing; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; autochthony; basal production; boreal; global change; dissolved organic carbon; food web efficiency; N deposition; phytoplankton; seston stoichiometry; whole lake enrichment; zooplankton; limnologi; Limnology;

    Abstract : 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. READ MORE

  4. 17. Solar radiation effects on decomposition and decomposers of plant litter in lakes

    Author : Måns Denward; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; glucosidase; photo inhibition; photo oxidation; littoral; lakes; ergosterol; fungi; phragmites; bacteria; UV-B; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : 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. READ MORE

  5. 18. The Role of Picophytoplankton in Lake Food Webs

    Author : Stina Drakare; Roger I. Jones; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; picophytoplankton; competition; heterotrophic bacteria; nutrients; humic DOC; Biologi; Biology; Biologi; limnologi; Limnology;

    Abstract : 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. READ MORE

  6. 19. Phytoplankton and bacterioplankton dynamics in a polymictic tropical lake

    Author : Rolf Erikson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; tropical lake; algae; bacteria; regulation; dynamics; interaction; Biologi; Biology; Biologi; limnologi; Limnology;

    Abstract : 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. READ MORE

  7. 20. Regulation and role of epiphytic nitrification and denitrification in macrophyte-dominated systems

    Author : Peder Eriksson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; marine biology; Hydrobiology; submerged; emergent; epiphyton; bacteria; nitrate; wetland; nitrogen; littoral; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Abstract : 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. READ MORE