Sökning: "food web"

Visar resultat 1 - 5 av 142 avhandlingar innehållade orden food web.

  1. 1. Ecology across Boundaries Food web coupling among and within ecosystems

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Pia Bartels; Uppsala universitet.; [2011]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cross-ecosystem; food web; habitat coupling; terrestrial-aquatic linkages; subsidy; allochthonous; lake ecosystem; population divergence; trait variation; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Freshwater ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Limnisk ekologi; NATURAL SCIENCES Biology; NATURVETENSKAP Biologi; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

    Sammanfattning : Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. LÄS MER

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

    Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap

    Författare :Johnny Berglund; Umeå universitet.; [2005]
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

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

    Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap

    Författare :Johan Lövgren; Umeå universitet.; [2004]
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 4. Complexity and Change in a Simple Food Web Studies in the Baltic Sea (FAO Area 27.IIId)

    Detta är en avhandling från Stockholm : Institutionen för systemekologi

    Författare :Henrik Österblom; Stockholms universitet.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Avian cholera; Bottom-up; Bycatch; Clupea harengus; Ecosystem; Food web; Gadus morhua; Halichoerus grypus; Regime shift; Sprattus sprattus; Top-down; Trophic cascade; Uria aalge; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Marine ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi Marin ekologi;

    Sammanfattning : An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. LÄS MER

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

    Detta är en avhandling från Umeå : Umeå universitet

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

    Sammanfattning : 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. LÄS MER