Sökning: "Nitrogen deposition"

Visar resultat 1 - 5 av 125 avhandlingar innehållade orden Nitrogen deposition.

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

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

    Sammanfattning : 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. LÄS MER

  3. 2. Epiphytic lichen responses to nitrogen deposition

    Författare :Otilia Johansson; Kristin Palmqvist; Johan Olofsson; Annika Nordin; Lars E Ericson; Peter Crittenden; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lichens; air pollution; nitrogen deposition; phosphorus; growth; chlorophyll a; boreal forest; field experiment; irrigation; carbon based secondary compounds; Lavar; luftföroreningar; alg; svamp; kväve; fosfor; skog; Terrestrial ecology; Terrestrisk ekologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Nitrogen (N) deposition has increased globally over the last 150 years and further increase is predicted for the future. Nitrogen is an important nutrient for lichens, involved in many processes in both photobiont and mycobiont.  However, N can be a stressor, causing many lichens and lichen communities to disappear with increased deposition. LÄS MER

  4. 3. Effects of nitrogen deposition on the growth, metabolism and activity of ectomycorrhizal fungi

    Författare :Magnus Ellström; MEMEG; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Nitrogen deposition; Ectomycorrhizal fungi; Symbiosis; SOM modification; Carbon starvation; Metabolism; Nitrogen leakage; IR-spectroscopy; Mesh bags; Microarray; Axenic growth; Transcriptomics.;

    Sammanfattning : Elevated nitrogen (N) deposition is an environmental problem that can affect plants and microorganisms, which are vital for the terrestrial N and carbon (C) cycles. This thesis has investigated the response of ectomycorrhizal fungi (EMF) to increased N deposition. LÄS MER

  5. 4. Microstructure and properties of welds in the lean duplex stainless steel LDX 2101

    Författare :Elin M. Westin; John Ågren; Hannu Hänninen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; HAZ; nitrogen; manganese; microstructure; austenite formation; phase balance; precipitates; element distribution; segregation; depletion; solidification; pitting corrosion resistance; solidification; element loss; evaporation; deposition; weld oxide; thermo-mechanical simulation; thermodynamic modelling; EPMA; XPS; post-weld cleaning; pickling; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik;

    Sammanfattning : Duplex stainless steels can be very attractive alternatives to austenitic grades due to their almost double strength at equal pitting corrosion resistance. When welding, the duplex alloys normally require addition of filler metal, while the commodity austenitic grades can often be welded autogenously. LÄS MER

  7. 5. External Mycelia of Mycorrhizal Fungi - responses to elevated N in forest ecosystems

    Författare :Lars Ola Nilsson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ericoid; arbuscular; mycorrhiza; nitrogen; deposition; fertilisation; nitrate leaching; retention; field; forest; Quercus; deciduous; Plant ecology; Växtekologi; mykologi; virologi; bakteriologi; mycology; Microbiology; External mycelia; ectomycorrhiza; Mikrobiologi; bacteriology; virology;

    Sammanfattning : Most plants live in symbiosis with mycorrhizal fungi. Mycorrhizal roots constitute the interface between the plant and the soil, and almost every fine root of forest trees in nitrogen-limited boreal and temperate forests is colonised by ectomycorrhizal (EM) fungi. LÄS MER