Sökning: "benthic"

Visar resultat 1 - 5 av 147 avhandlingar innehållade ordet benthic.

  1. 1. Effects of warming and browning on benthic and pelagic ecosystem components in shallow lakes

    Författare :Francisco Rivera Vasconcelos; Sebastian Diehl; Jan Karlsson; Christopher T. Solomon; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; benthic; pelagic; algae; consumers; browning; warming; shallow lakes; food web; dissolved organic matter;

    Sammanfattning : The majority of lakes on Earth are shallow, unproductive and located at high latitudes. These lakes are experiencing big changes due to climate change, where two environmental drivers operate simultaneously, browning and warming. How they affect lake ecosystems is not well understood. LÄS MER

  2. 2. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

    Författare :Anders Tengberg; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

    Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER

  3. 3. Persistent organic pollutants in benthic foodwebs

    Författare :Niklas Holmqvist; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; Intraspecific interactions; streams; nutrients; lakes; crayfish; eels; Persistent organic pollutants; Benthic foodwebs; akvatisk ekologi; Environmental chemistry; Miljökemi;

    Sammanfattning : Concentrations of persistent organic pollutants (POPs) in aquatic biota are dependent on several factors both on individual and on system level. Bioaccumulation of POPs in pelagic biota in lakes as well as fish in streams has been shown to be dependent on nutrient regime of the system. LÄS MER

  4. 4. Biomass and Nutrient Status of Benthic Algae in Lakes

    Författare :Maria Kahlert; Alan Steinman; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; benthic algae; patchiness; C:N:P ratio; nutrient recycling; grazer; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; limnologi; Limnology;

    Sammanfattning : For a complete picture of the lake ecosystem, it is necessary to understand the mechanisms regulating biomass and nutrient status (nutrient limitation, optimal supply, or surplus) of benthic algae, which are important primary producers and a food resource for grazers. This thesis gives an overview of the natural variation of benthic algae at different scales of space and time and on different substrates, and unravels some of the underlying factors. LÄS MER

  5. 5. Arctic Ocean benthic foraminifera preservation and Mg/Ca ratios : Implications for bottom water palaeothermometry

    Författare :Natalia Barrientos; Helen Coxall; Martin Jakobsson; Steve Barker; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; benthic foraminifera; Mg Ca-temperature; calcite preservation; maringeologi; Marine Geology;

    Sammanfattning : Reconstructions of Arctic Ocean palaeotemperatures are needed to disentangle natural variability from anthropogenic changes and understand the role of ocean heat transport in forcing or providing feedbacks on Arctic climate change. Despite known complications with calcareous microfossil preservation in Arctic Ocean sediments, calcareous benthic foraminifera can be common in interglacial sequences. LÄS MER