Search for dissertations about: "nitrogen retention"

Showing result 1 - 5 of 59 swedish dissertations containing the words nitrogen retention.

2. 1. Riverine nitrogen : Analysis and modelling under Nordic conditions

   Author : Berit Arheimer; Linköpings universitet; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

   Abstract : The Baltic Sea in northern Europe is a brackish water body where eutrophication is considered a serious problem, partly as a result of high nitrogen load from rivers. This thesis includes statistical analysis of nitrogen behaviour in 55 small catchments. The results were used for further development of a dynamic model (HBV-N). READ MORE

4. 2. Nitrogen removal in treatment wetlands : Factors influencing spatial and temporal variations

   Author : Sofia Kallner Bastviken; Karin Sundblad-Tonderski; Jos Verhoeven; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Wetlands; denitrification; macrophytes; nitrogen; nitrification; model; treatment wetlands; potential denitrification; Biology; Biologi;

   Abstract : Decreasing the nitrogen transport from land to surrounding seas is a major task throughout the world to limit eutrophication of the coastal areas. Several approaches are currently used, including the establishment of wetlands, to decrease the transport of nitrogen. READ MORE

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

   Author : Lars Ola Nilsson; Biologiska institutionen; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 4. The role of benthic macrofauna in nitrogen cycling in eutrophic lake sediment

   Author : Jonas Martin Svensson; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen retention; nitrous oxide; oligochaetes; chironomids; mineralisation; nitrification; denitrification; eutrophic; sediment; lake; Macrofauna; nitrogen cycling; fish reduction.; Ecology; Ekologi;

   Abstract : This thesis concerns the role of sediment-living macrobenthos in the cycling of nitrogen species and nitrogen transformation in eutrophic freshwater sediments. In my thesis I have, employing 15N-isotope techniques in laboratory experiments, shown the importance of infaunal chironomid larvae and oligochaetes on denitrification in eutrophic lake sediments. READ MORE

7. 5. The influence of multiscale hyporheic flow on solute transport : Implications for stream restoration enhancing nitrogen removal

   Author : Ida Morén; Anders Wörman; Joakim Riml; Roy Haggerty; KTH; []
   Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Hyporheic exchange flow; Hydrological modeling; Solute transport; Stream restoration; Nitrogen; Power spectral analysis; Hydraulic and Hydrologic Engineering; Hydraulik och teknisk hydrologi;

   Abstract : Stream water that flows into and out of streambeds is called hyporheic exchange flow (HEF).It continuously interacts with groundwater and thereby affect the water quality of local streamreaches as well as downstream recipients by providing an environment where solutes andenergy can be retained and degraded. READ MORE