Sökning: "Nitrogen fluxes"

Visar resultat 1 - 5 av 49 avhandlingar innehållade orden Nitrogen fluxes.

1. 1. Nitrogen Losses from a Clay-rich Soil used for Cereal Production in south-western Sweden

   Författare :Magdalena Wallmann; Göteborgs universitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; nitrogen; fertilisers; soil; nitrous oxide; nitrogen leaching; 15N; nitrogen use efficiency; nitrogen budget; agriculture; Sweden;

   Sammanfattning : Addition of fertiliser nitrogen (N) in crop production increases yields and protein contents, but all is not taken up by the crop. Instead, some of the N is lost to air and waters, contributing e.g. to climate change, stratospheric ozone depletion, eutrophication and acidification. LÄS MER

3. 2. Nitrogen land-sea fluxes in the Baltic Sea catchment : Empirical relationships and budgets

   Författare :Hanna Eriksson Hägg; Christoph Humborg; Carl-Magnus Mörth; Hans Borg; Sybil Seitzinger; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen fluxes; Baltic Sea; primary emissions; riverine export; Scenario analysis; climate change; animal protein consumption; fertilizer use; Environmental chemistry; Miljökemi; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : In this thesis empirical relationships and modeling tools are used to describe the relationship between human activities and meso- and large scale riverine N fluxes from land to sea. On a large scale Paper I showed that by only having knowledge about human population size and runoff one can estimate the riverine export of DIN (r2= 0.76). LÄS MER

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

   Författare :Anders Tengberg; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; 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. 4. Nitrogen-cycling tracing methods : Case studies at cold-climate mine sites in northern Sweden

   Författare :Lino Nilsson; Anders Widerlund; Andreas Bryhn; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geochemistry; Tillämpad geokemi;

   Sammanfattning : High nitrogen effluents from mine sites is an environmental issue which has received relatively little attention historically. In recent years a number of studies have showed the environmental effects of high nitrogen discharge to natural water bodies, which include local eutrophication, high risk of acute reducing conditions and changed species composition in the receiving waters. LÄS MER

7. 5. Microphytobenthos and Nitrogen Fluxes, with Special Emphasis on Dissolved Organic Nitrogen (DON)

   Författare :Frank Linares; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : .... LÄS MER