Sökning: "Excess nitrogen"

Visar resultat 1 - 5 av 52 avhandlingar innehållade orden Excess nitrogen.

  1. 1. Responses of peatland vegetation to enhanced nitrogen

    Författare :Magdalena Wiedermann; Lars Ericson; Juul Limpens; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sphagnum; nitrogen; peatlands; soluble amino acids; gradient study; field experiment; Biology; Biologi;

    Sammanfattning : Human alteration of the global nitrogen (N) cycle has had major impacts on naturally N-limited ecosystems worldwide. Peatlands, dominated by peat mosses, Sphagnum species, represent one such sensitive ecosystem. LÄS MER

  3. 2. Control factors of the marine nitrogen cycle : The role of meiofauna, macrofauna, oxygen and aggregates

    Författare :Stefano Bonaglia; Patrick Crill; Volker Brüchert; Per Hall; Chritoph Humborg; Risgaard-Petersen Nils; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen cycle; denitrification; DNRA; anammox; anoxia; hypoxia; eutrophication; meiofauna; macrofauna; aggregates; cyanobacteria; Baltic Sea; geokemi; Geochemistry;

    Sammanfattning : The ocean is the most extended biome present on our planet. Recent decades have seen a dramatic increase in the number and gravity of threats impacting the ocean, including discharge of pollutants, cultural eutrophication and spread of alien species. LÄS MER

  4. 3. Nitrogen and Redox Metabolism in Saccharomyces cerevisiae

    Författare :Eva Albers; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Saccharomyces cerevisiae; glutamate; protein expression; anaerobic physiology; nitrogen metabolism; redox; serine;

    Sammanfattning : Anaerobic conversion of glucose to ethanol by the yeast Saccharomyces cerevisiae has been studied. Glycerol is formed as a by-product in order to maintain the overall redox balance. LÄS MER

  5. 4. Bark lesions and sensitivity to frost in beech and Norway spruce

    Författare :Anna Maria Jönsson; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Picea abies; Multiple stress; Mineral nutrient balance; Liming; Lichen indices; Fagus sylvatica; Cryptococcus fagisuga; Excess nitrogen; Vitality fertilization; Plant ecology; Växtekologi;

    Sammanfattning : Strong temperature fluctuations and pathogen attacks can cause bark lesions, visible signs of wounds in the phloem and cambium. Pathogenic insects and fungi are able to invade lesions that have not healed, further increasing the damage. LÄS MER

  7. 5. Investigating ruminal nitrogen metabolism : in vitro and in vivo studies using ¹⁵N-labelled forage nitrogen fractions

    Författare :Merko Vaga; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Nitrogen losses from dairy production have negative impacts on the environment and on production economics. In Northern Europe, dairy cattle are mainly fed forage-based diets supplemented with protein feeds such as rapeseed meal. LÄS MER