Sökning: "total nitrogen"

Visar resultat 1 - 5 av 225 avhandlingar innehållade orden total nitrogen.

  1. 1. Cyanobacterial Nitrogen Fixation in the Baltic Sea : With focus on Aphanizomenon sp

    Författare :Jennie B. Svedén; Jakob Walve; Helle Ploug; Angela Wulff; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; cyanobacteria; Baltic Sea; nitrogen fixation; Aphanizomenon sp.; dissolved nitrogen; particulate nitrogen; sedimentation; marin ekologi; Marine Ecology;

    Sammanfattning : Cyanobacteria are widely distributed in marine, freshwater and terrestrial habitats. Some cyanobacterial genera can convert di-nitrogen gas (N2) to bioavailable ammonium, i.e. perform nitrogen (N) fixation, and are therefore of profound significance for N cycling. LÄS MER

  2. 2. Vegetation changes on Swedish mires : Effects of raised temperature and increased nitrogen and sulphur influx

    Författare :Urban Gunnarsson; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Acidification; growth; long-term studies; mires; nitrogen; species richness; Sphagnum; succession; sulphur; temperature; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Since the start of the industrialisation, the deposition of nitrogen and sulphur and the atmospheric concentrations of greenhouse gases have increased. The main objectives of this study were to find how these changes in climate and deposition can change the vegetation of mire ecosystems and the growth of Sphagnumspecies. LÄS MER

  3. 3. Data-driven analysis of water and nutrient flows: Case of the Sava River Catchment and comparison with other regions

    Författare :Lea Levi; Vladimir Cvetkovic; Georgia Destouni; Roko Andričević; Ronny Berndtsson; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; River catchment; Transboundary; Hydro-climatic change; Total nitrogen; Total phosphorus; CMIP5; Mark- och vattenteknik; Land and Water Resources Engineering;

    Sammanfattning : A growing human population and demands for food, freshwater and energy are causing extensive changes in the water and biogeochemical cycles of river catchments around the world. Addressing and investigating such changes is particularly important for transboundary river catchments, where they impose additional risk to a region’s stability. LÄS MER

  4. 4. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

    Författare :Anders Tengberg; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

    Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER

  5. 5. Ectomycorrhizal fungi: Their role in nitrogen retention and carbon sequestration in northern coniferous forests

    Författare :Adam Bahr; MEMEG; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ectomycorrhizal fungi; Carbon sequestration; Nitrogen deposition; Nitrogen leakage; Field survey; Boreo-nemoral forest; Boreal Forest; Ergosterol; Free ergosterol; Mesh-bags; Multivariate analysis;

    Sammanfattning : Almost all northern forest tree species live in symbioses with ectomycorrhizal fungi (EMF). The trees allocate up to half of the photoassimilated carbon (C) through the roots to EMF. In return EMF deliver nutrients from both inorganic and organic sources in the soil, as well as water. LÄS MER