Search for dissertations about: "Microbial food web"

Showing result 1 - 5 of 28 swedish dissertations containing the words Microbial food web.

  1. 1. Flagellates in the marine microbial food web the ecology of a mixotrophic nanoflagellate, Ochromonas sp

    University dissertation from Umeå : Umeå universitet

    Author : Agneta Andersson-Nordström; [1989]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Microbial food web; flagellates; Ochromonas sp.; mixotrophy; size- selective grazing; remineralisation; excretion of DFAA;

    Abstract : Nanoflagellates were found to be abundant in a coastal area of the northern Bothnian Sea. The maximum concentration of nanoflagellates, approximately 8000 cells ml-1, was observed in July, coinciding with a decrease in the abundance of cyanobacteria. READ MORE

  2. 2. Mechanisms structuring the pelagic microbial food web Importance of resource and predation

    University dissertation from Umeå : Umeå universitet

    Author : Kristina Samuelsson; Umeå universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; pelagic microbial food web; bacteria; flagellates; ciliates; phytoplankton; mixotrophy; nutrient status; predation limitation; resource limitation; Baltic Sea; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi;

    Abstract : Temporal and spatial variations of pelagic microorganisms in the northern Baltic Sea were studied, as well as factors influencing their abundance and growth rates. Three main questions were asked 1) How does increased productivity influence the structure of the microbial food web? 2) Does predation limitation vary between trophic levels? 3) What is the relative importance of resource and predation limitation at different trophic levels?A field study in the northern Baltic Sea showed that dominating protozoa, flagellates and ciliates, increased with increasing primary productivity from north to south. READ MORE

  3. 3. Pelagic microorganisms in the northern Baltic Sea Ecology, diversity and food web dynamics

    University dissertation from Umeå : Ekologi, miljö och geovetenskap

    Author : Johnny Berglund; Umeå universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; resource limitation; predation limitation; microbial food web; heterotrophic microorganisms; nanoflagellates; ciliates; protists; resource heterogeneity; chrysomonads; chrysophytes; group-specific PCR-DGGE primers; Baltic Sea; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi Marin ekologi;

    Abstract : Heterotrophic microorganisms are important for the flow of carbon and nutrients in the sea. Bacteria, nanoflagellates and ciliates are relevant components of the pelagic food web. In order to be able to predict the outcome of e.g. READ MORE

  4. 4. Food web dynamics in open and closed systems

    University dissertation from Umeå : Ekologi, miljö och geovetenskap

    Author : Johan Lövgren; Umeå universitet.; [2004]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; allochtonous input; cross habitat foraging; donor control; heterogeneity within trophic level; compensation; food web; littoral; Ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi;

    Abstract : This thesis is a summary of enclosure and microcosm experiments that aimed to study the impact of allochtonous subsidies on food web dynamics in a heterogeneous food web. In the enclosure studies, a three trophic level littoral food web was used. READ MORE

  5. 5. The role of allelopathy in microbial food webs

    University dissertation from Växjö, Kalmar : Linnaeus University Press

    Author : Astrid Weissbach; Linnéuniversitetet.; [2011]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Freshwater ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology; Microbial food web; Allelopathy; Alexandrium tamarense; Prymnesium parvum; Infochemicals; marine plankton community;

    Abstract : Phytoplankton produce allelochemicals; excreted chemical substances that are affecting other microorganisms in their direct environment.In my thesis, I investigated strain specific variability in the expression of allelochemicals of the harmful flagellate Prymnesium parvum, that is euryhaline but mainly bloom forming in brackish water. READ MORE