Search for dissertations about: "Nitrogen cycle"

Showing result 1 - 5 of 116 swedish dissertations containing the words Nitrogen cycle.

  2. 1. Marine nitrogen fixation : Cyanobacterial nitrogen fixation and the fate of new nitrogen in the Baltic Sea

    Author : Isabell Klawonn; Helle Ploug; Lasse Riemann; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; biogeochemistry; nitrogen cycling; nitrogen fixation; cyanobacteria; Baltic Sea; Marine Ecology; marin ekologi;

    Abstract : Biogeochemical processes in the marine biosphere are important in global element cycling and greatly influence the gas composition of the Earth’s atmosphere. The nitrogen cycle is a key component of marine biogeochemical cycles. READ MORE

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

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

    Abstract : 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. READ MORE

  5. 3. Nitrogen Cycling at Cold Climate Mine Sites in Northen Sweden

    Author : Lino Nilsson; Anders Widerlund; Anders Lundqvist; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nitrogen; Mining; Cycling; nutrients; Isotopes; Nitrogen-model; modelling; numerical-modelling; Isotope-tracing; Tracing; Isotope; geochemistry; Applied Geology; Tillämpad geologi;

    Abstract : High nitrogen discharge from mining sites has been an environmental issue that has been closely studied in the recent years. The environmental effects of high nitrogen discharge are mainly eutrophication, but can also lead to changed species composition and algae blooms. READ MORE

  6. 4. Strategic nitrogen management in stockless organic cropping systems : redistribution of residual biomass for improved energy and nitrogen balance

    Author : Tora Råberg; Sweden SLU; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; bioenergy; biomass management; crop rotation; ecological intensification; green manure; life cycle assessment; nitrogen cycling; organic agriculture; soil incubation; stockless cropping systems;

    Abstract : Agriculture faces the challenge of producing high yields to feed a growing world population, while simultaneously addressing environmental problems such as eutrophication, emissions of greenhouse gases, loss of biodiversity and soil degradation. Organic farming can be part of the solution, as it promotes biodiversity, uses less energy for fertiliser production and often has higher inputs of organic matter to soil than conventional farming. READ MORE

  7. 5. Soil-living archaea: Influence of pH, carbon and nitrogen on their abundance and activity

    Author : Anna Sterngren; MEMEG; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Archaea; ammonia-oxidizing archaea; soil; AOA; AOB; root exudates; gross nitrification; qPCR; pH; carbon cycle; nitrogen cycle;

    Abstract : During the last decade it has been discovered that around 2% of the soil-living prokaryotes belong to the domain Archaea. In many soils the most abundant archaeal group is the ammonia-oxidizing archaea (AOA) that, in addition to ammonia-oxidizing bacteria (AOB), preform the first and rate-limiting step in the nitrification process. READ MORE