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Visar resultat 1 - 5 av 34 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Haustoria regulation in the facultative parasitic plant Phtheirospermum japonicum

    Författare :Anna Kokla; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Parasitic plants are important agricultural pests that lead to considerable yield losses annually. Parasitic plants that completely rely on their hosts for their survival are known as obligatory parasites, whereas those independent of their hosts but parasitize under the right conditions are known as facultative parasitic plants. LÄS MER

  3. 2. Nutrient imbalance in Norway spruce

    Författare :Gunnar Thelin; Avdelningen för kemiteknik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Silviculture; Växtekologi; Plant ecology; nitrogen saturation; base saturation; pH; multiple limitation; deficiency; copper; boron; potassium; pollution; sustainability; conifers; forestry; forestry technology; Skogsvetenskap; skogsbruk; skogsteknik; Soil Science; agricultural hydrology; Lantbrukshydrologi; marklära;

    Sammanfattning : The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. LÄS MER

  4. 3. Red algal starch metabolism : effects of endosymbionts and nutrient status on starch metabolising enzymes

    Författare :Pi Nyvall; Mark Ragan; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; växtfysiologi; Plant Physiology;

    Sammanfattning : Many different organisms occur as endosymbionts of red algae and while some are highly pathogenic others have little effect on the host. An endosymbiotic fungus, found in our culture of Gracilariopsis sp., was characterised and identified as a Chytridiomycete. It was named Thalassochytrium gracilariopsidis and probably belongs to a new order. LÄS MER

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

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

    Sammanfattning : 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. LÄS MER

  7. 5. Seagrasses and Eutrophication : Interactions between seagrass photosynthesis, epiphytes, macroalgae and mussels

    Författare :Esther Francis Mvungi; Mats Björk; Thomas J. Lyimo; Jens Borum; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CO2; epiphytes; eutrophication; mussels; pH; Photosynthetic activities; seagrasses; Ulva; Plant physiology; Växtfysiologi; Plant Physiology; växtfysiologi;

    Sammanfattning : Seagrass meadows are highly productive, ecologically and economically valuable ecosystems. However, increased human activities along the coastal areas leading to processes such as eutrophication have resulted in the rapid loss and deterioration of seagrass ecosystems worldwide. LÄS MER