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Visar resultat 1 - 5 av 65 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Phytoplankton and Physical Disturbance : Seasonal dynamics in temperate Lake Erken, Sweden

    Författare :Yang Yang; Kurt Pettersson; Peeter Nõges; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phytoplankton dynamics; high-frequency measurements; thermal stratification; water column stability; equilibrium; disturbance;

    Sammanfattning : Phytoplankton mirrors changes in the environment and plays an important role in biogeochemical processes. Phytoplankton dynamics is the outcome of both autogenic succession and external disturbances. LÄS MER

  3. 2. Effects of dissolved humic matter on phytoplankton

    Författare :Jessica von Einem; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; PAR; DOC; Water colour; production;

    Sammanfattning : Water colour is currently increasing in thousands of lakes in the northern hemisphere due to an increased input of terrestrial dissolved organic carbon (DOC), and more specifically coloured disscolved humic matter (DHM). I studied how water colour affects the light climate in the epilimnion and, as a consequence, phytoplankton biomass, species composition and production in lakes in southern Sweden. LÄS MER

  4. 3. The dissolved organic carbon released from lake phytoplankton : biochemical composition and bacterial utilization

    Författare :Ingvar Sundh; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  5. 4. Pigment and Thiamine Dynamics in Marine Phytoplankton and Copepods

    Författare :Ingrid Wänstrand; Pauli Snoeijs; Marianne Pedersén; Helmut Hillebrandt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; phytoplankton composition; pigments; chemotaxonomy; inorganic nutrients; pelagic copepods; grazing; astaxanthin; thiamine; mesocosm experiments; marine food webs; eutrophication; Baltic Sea; Biologi; Biology; Biologi;

    Sammanfattning : Based on a field study and several mesocosm experiments, I evaluated the use of pigments as chemotaxonomical biomarkers for phytoplankton community composition in the Baltic Sea and I examined effects of inorganic nutrients on the dynamics of carotenoids and thiamine (vitamin B1) at the phytoplankton–copepod level in marine pelagic food webs. My results show that HPLC pigment analysis combined with CHEMTAX data processing was an accurate alternative to microscopic analysis of Baltic Sea phytoplankton. LÄS MER

  7. 5. Phenotypic evolution and adaptive strategies in marine phytoplankton (Coccolithophores)

    Författare :Luka Šupraha; Jorijntje Henderiks; Bente Edvardsen; Jeremy Young; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Coccolithophores; Life-Cycle; Phytoplankton; Nutrient limitation; Temperature; Microscopy; High-throughput sequencing; Taxonomy;

    Sammanfattning : Coccolithophores are biogeochemically important marine algae that interact with the carbon cycle through photosynthesis (CO2 sink), calcification (CO2 source) and burial of carbon into oceanic sediments. The group is considered susceptible to the ongoing climate perturbations, in particular to ocean acidification, temperature increase and nutrient limitation. LÄS MER