Avancerad sökning

Visar resultat 1 - 5 av 59 avhandlingar som matchar ovanstående sökkriterier.

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

    Författare :Johnny Berglund; Agneta Andersson; Ramon Massana; Umeå universitet; []
    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; Marine ecology; 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. 2. Cascading extinctions in food webs : local and regional processes

    Författare :Anna Eklöf; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cascading extinctions; complexity; connectance; dispersal; food web; local dynamics; regional dynamics; resistance; spatial structure; species loss;

    Sammanfattning : Ecological communities all over the world are loosing biodiversity due to different kinds of human activities and there is an urgent need of understanding how those losses affect the function of the ecosystems on which we all depend. The community's response to species losses is likely to depend on both the structure of the local community as well as its interactions with surrounding communities. LÄS MER

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

    Författare :Johan Lövgren; Lennart Persson; Jonathan Chase; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; allochtonous input; cross habitat foraging; donor control; heterogeneity within trophic level; compensation; food web; littoral; Ekologi; Terrestrial; freshwater and marine ecology; 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

  5. 4. Baltic Sea food web dynamics and response to environmental change

    Författare :Susa Niiranen; Thorsten Blenckner; Olle Hjerne; Magnus Huss; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; food web; modelling; Ecopath with Ecosim; model uncertainty; Marine Ecology; marin ekologi;

    Sammanfattning : The Baltic Sea ecosystem is subject to a combination of external pressures such as fishery, changing climate and land-based nutrient inputs. In combination with internal food web mechanisms these external forces can lead to changes in the food web structure and function. LÄS MER

  7. 5. Thiamin (vitamin B1) in the aquatic food web

    Författare :Emil Fridolfsson; Samuel Hylander; Michael T. Brett; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; zooplankton; thiamin; transfer; food web dynamics; micronutrient; vitamin; Baltic Sea; community composition; M74; salmon; B1; växtplankton; djurplankton; tiamin; överföring; födoväv; mikronäringsämne; vitamin; Östersjön; B1; lax; Ecology; Ekologi;

    Sammanfattning : Thiamin (vitamin B1) is required for several life-sustaining processes in most organisms and cells, e.g. in the conversion of food to energy. It also serves as an antioxidant and is important for proper nerve signaling. LÄS MER