Sökning: "Tobias Vrede"

Hittade 4 avhandlingar innehållade orden Tobias Vrede.

  1. 1. The role of crustacean zooplankton in pelagic nutrient cycling

    Författare :Tobias Vrede; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; nutrients; freshwaters; food web; Cladocera; Calanoida; stoichiometry; Biologi; Biology; Biologi; limnologi; Limnology;

    Sammanfattning : Herbivorous crustacean zooplankton link phytoplankton and other microorganisms withhigher trophic levels in pelagic food webs. Crustaceans show little intraspecificvariation in somatic C:N:P elemental ratios, which may have implications for theregulation of zooplankton growth and for nutrient cycling. LÄS MER

  3. 2. Productivity and carbon transfer in pelagic food webs in response to carbon, nutrients and light

    Författare :Carolyn Faithfull; Ann-Kristin Bergström; Tobias Vrede; Kathryn Cottingham; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bacterial production; phytoplankton production; mesocosms; food webs; carbon; nutrients; light; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; limnologi; Limnology;

    Sammanfattning : Some of the major problems we face today are human induced changes to the nitrogen (N), phosphorus (P) and carbon (C) cycles. Predicted increases in rainfall and temperature due to climate change, may also increase dissolved organic matter (DOM) inflows to freshwater ecosystems in the boreal zone. LÄS MER

  4. 3. Food Quality Effects on Zooplankton Growth and Energy Transfer in Pelagic Freshwater Food Webs

    Författare :Jonas Persson; Tobias Vrede; Peter Eklöv; Ellen van Donk; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; elemental stoichiometry; phosphorus; polyunsaturated fatty acids; EPA; oligotrophic lakes; empirical modelling; Daphnia; Cladocera; Copepoda; Ekologi;

    Sammanfattning : Poor food quality can have large negative effects on zooplankton growth and this can also affect food web interactions. The main aims of this thesis were to study the importance of different food quality aspects in Daphnia, to identify potentially important differences among zooplankton taxa, and to put food quality research into a natural context by identifying the importance of food quality and quantity in lakes of different nutrient content. LÄS MER

  5. 4. The role of terrestrial and phytoplankton-derived organic matter in planktonic food webs

    Författare :Anja Wenzel; Ann-Kristin Bergström; Tobias Vrede; Maarten Boersma; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Daphnia; phytoplankton; heterotrophic bacteria; terrestrial particulate organic material; food quality; food quantity; fatty acids; oligotrophic; Light:Nutrient-Hypothesis; limnologi; Limnology;

    Sammanfattning : Lakes are important global ecosystems and many of them are nutrient-poor (unproductive). Especially in northern boreal latitudes, lakes may be heavily subsidized by terrestrial organic material (t-OM) from peat layers in the catchment. LÄS MER