Search for dissertations about: "Microbial food web"

Showing result 1 - 5 of 32 swedish dissertations containing the words Microbial food web.

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

    Author : Agneta Andersson-Nordström; []
    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

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

    Author : Kristina Samuelsson; Agneta Andersson; Christiane Lancelot; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; pelagic microbial food web; bacteria; flagellates; ciliates; phytoplankton; mixotrophy; nutrient status; predation limitation; resource limitation; Baltic Sea; Ekologi; Terrestrial; freshwater and marine ecology; 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

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

    Author : Johnny Berglund; Agneta Andersson; Ramon Massana; Umeå universitet; []
    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; Marine ecology; 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

  6. 4. Microbial communities : descriptors of environmental change in marine ecosystems

    Author : Li Zhao; Agneta Andersson; Xiao-Ru Wang; Alexander Eiler; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : In northern marginal seas, like the northern Baltic Sea, climate change will lead to many alterations, for example increased inflows of nutrients and dissolved organic matter (DOM). Nutrients and DOM are fundamental drivers shaping marine microbial communities, including both bacterial and phytoplankton populations. READ MORE

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

    Author : Astrid Weissbach; Catherine Legrand; Ellen Van Donk; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Microbial food web; Allelopathy; Alexandrium tamarense; Prymnesium parvum; Infochemicals; marine plankton community; Freshwater ecology; Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology;

    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