Search for dissertations about: "resource limitation"

Showing result 1 - 5 of 42 swedish dissertations containing the words resource limitation.

  2. 1. 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

  4. 2. 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

  5. 3. Microalgal solutions in Nordic conditions : industries transition toward resource recovery?

    Author : Lina Mattsson; Catherine Legrand; Elin Lindehoff; Hanna Farnelid; Kristian Spilling; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Microalgae; algal cultivation; polyculture; resource recovery; seasonal variation; industrial partnership; CO2 mitigation; nitrogen removal; community composition; Ecology; Ekologi; Environmental Biotechnology; Miljöbioteknik; Miljövetenskap; Environmental Science; Akvatisk ekologi; Aquatic Ecology; Mikrobiologi; Microbiology;

    Abstract : Microalgal solutions can through photosynthesis recover greenhouse gas (CO2) and nutrients from industrial waste, reducing climate footprint and eutrophication. An added value to the process is algal biomass containing lipids, proteins, and carbohydrates with commercial potential for biofuel, feed, and fertilizer. READ MORE

  6. 4. Effects of farmland heterogeneity at multiple spatial and temporal scales on house sparrow (Passer domesticus) population ecology

    Author : Maria von Post; Biodiversitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Farmland heterogeneity; house sparrow; agricultural intensification; farm specialisation; landscape complementation; resource separation; population limitation;

    Abstract : Strong declines of European farmland birds in recent decades are assumed to be caused by decreased food availability resulting from agricultural intensification and concomitant loss of farmland heterogeneity. One of the species suffering particularly strong declines in NW European countries is the house sparrow. READ MORE

  7. 5. Soil phosphorus – a multidimensional resource that plays an important role for grassland plant species richness

    Author : Jakob Sandberg; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; niche dimension; nutrient limitation; niche differentiation; competition; soil nitrogen; soil phosphorus; plant diversity; species richness; Grassland; land use; landscape scale;

    Abstract : The semi-natural grassland habitats contain an important part of the plant diversity in Europe. Changes in farming practices have lead to drastic decreases in plant species richness. The aim of the present thesis is to contribute to the knowledge about mechanisms governing the plant species richness in grasslands with emphasis on soil nutrients. READ MORE