Sökning: "Kvävefixering"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet Kvävefixering.

1. 1. Nitrogen fixation among marine bacterioplankton

   Författare :Kjärstin H. Boström; Lasse Riemann; Åke Hagström; Grieg Steward; Högskolan i Kalmar; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bacterioplankton; Nitrogen fixation; Bakterioplankton; Kvävefixering; Cyanobakterier; Kvävefixerande bakterier; Microbiology; Mikrobiologi; Mikrobiologi; Microbiology;

   Sammanfattning : While bacterioplankton indisputably control vital biogeochemical paths in the cycling of carbon and nutrients in the world’s oceans, our knowledge about the functional and genetic diversity of bacterioplankton communities is negligible. In this thesis, molecular and more traditional microbiological methods were used to study the specific function of N2-fixation and in a general sense diversity of marine bacterioplankton species. LÄS MER

3. 2. Uptake of and Preference for Nitrate, Ammonium and Amino Acids by Understory Species in Deciduous Forests

   Författare :Magnus Zätterström; Infektionsmedicin; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Soil Science; agricultural hydrology; Lantbrukshydrologi; marklära; Fixation of nitrogen; Kvävefixering; Växtekologi; Plant ecology; wild plants.; understory; rhizosphere; preference; oak forests; NRA; nitrification; nitrate; delta15N; 15N; glutamate; glycine; drying-rewetting; amino acids; ammonium;

   Sammanfattning : AbstractThe uptake of different nitrogen forms by understory species was studied in field and laboratory. Species of the understory in deciduous forests have previously been thought to take up and assimilate only inorganic nitrogen sources. LÄS MER

4. 3. Nutrient cycling in agroecosystems: nitrogen cycling in southern Sweden in the 1850s and two Tanzanian villages in the 1990s

   Författare :Lars-Erik Williams; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nutrient; nutrient model; nutrient cycling; nitrogen fixation; nitrogen budget; mixed system; miombo; manure; livestock; land use; historical system; food production; efficiency; crops; agroecosystem; carrying capacity; phosphorus; Scania; sustainability; Plant ecology; Växtekologi;

   Sammanfattning : This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. LÄS MER

5. 4. Molecular detection of abundance and activity of marine, symbiotic, N2-fixing cyanobacteria

   Författare :Linnéa Ström; Rachel Foster; Daniel Lundin; Katharina Pawlowski; Rehab El-Shehawy; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Diatom Diazotroph Association; Richelia; Iron; Phosphorus; Nitrogen; nifH; pstS; exbB; rnpA; växtfysiologi; Plant Physiology; marinbiologi; Marine Biology;

   Sammanfattning : Marine primary productivity in large parts of the oceans is supported by nitrogen fixers (diazotrophs). Richelia, a genus of multiple closely related species of heterocystous filamentous cyanobacterial diazotrophs, are often found in symbioses with a few genera of diatoms. Several Richelia species: R. euintracellularis, R. LÄS MER

7. 5. Ecology and evolution of coastal Baltic Sea 'dead zone' sediments

   Författare :Elias Broman; Mark Dopson; Nils Risgaard-Petersen; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; sediment; oxygen; metatranscriptomics; metagenomics; 16S rRNA gene; RNA-seq; dead zone; re-oxygenation; Akvatisk ekologi; Aquatic Ecology;

   Sammanfattning : Since industrialization and the release of agricultural fertilizers began, coastal and open waters of the Baltic Sea have been loaded with nutrients. This has increased the growth of algal blooms and because a portion of the algal organic matter sinks to the sea floor, hypoxia has increased. LÄS MER