Search for dissertations about: "biogeokemi"

Showing result 1 - 5 of 15 swedish dissertations containing the word biogeokemi.

  2. 1. The role of sediments in the biogeochemical cycles of nutrients in the Gulf of Riga

    Author : Juris Aigars; Matti Perttilä; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biogeochemistry; biogeokemi;

    Abstract : The sediment biogeochemistry of C, N, P and biologic silica (BSi) plays an important role in cycling of these elements in aquatic ecosystems. In shallow coastal and estuarine systems, water-sediment nutrient dynamics can influence biological processes (e.g., primary production) in overlying waters. READ MORE

  4. 2. The geochemistry of two selected areas of the deep sea, the TAG hydrothermal mound, Mid-Atlantic Ridge and the Lomonosov Ridge, central Arctic Ocean

    Author : Hakam Al-Hanbali; Gustaf Arrhenius; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biogeochemistry; biogeokemi;

    Abstract : .... READ MORE

  5. 3. Hydrothermal alteration of organic matter at spreading centers

    Author : Eva Andersson; Bernd R.T. Simoneit; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Biogeochemistry; biogeokemi;

    Abstract : Alteration of organic matter, mainly amino acids, at sub-seafloor hydrothermal conditions has been investigated by performing laboratory experiments and by studying deep-sea sediments from hydrothermally active areas on the northern Juan de Fuca Ridge, northeast Pacific Ocean.Quaternary sediments from Middle Valley and the eastern flank of the Juan de Fuca Ridge recovered during the Ocean Drilling Program Legs 139 and 168 have been analyzed for total hydrolyzable amino acid concentrations, individual amino acid abundances and stereochemistry in order to evaluate the effects of hydrothermal stress on the decomposition of sedimentary amino acids. READ MORE

  6. 4. Drivers of increasing iron concentrations in freshwaters

    Author : Caroline Björnerås; Enhet akvatisk ekologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Järn; Akvatisk ekologi; Biogeokemi; Brunifiering; Iron; Freshwaters; Biogeochemistry; Brownification; Iron biogeochemistry; Browning; Freshwaters;

    Abstract : Iron (Fe) concentrations are increasing in freshwaters (lakes and streams) in Sweden, as well as in other regions in northern Europe. Together with increasing concentrations of organic matter, Fe is contributing to the ongoing browning of freshwaters, which may have serious ecological consequences and implications for ecosystem services. READ MORE

  7. 5. Benthic metabolism and sediment nitrogen cycling in Baltic sea coastal areas : the role of eutrophication, hypoxia and bioturbation

    Author : Stefano Bonaglia; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Eutrophication; Sediment; Benthic Flux; Nitrogen Cycle; Denitrification; Baltic Sea; Biogeochemistry; biogeokemi; marin- och brackvattensekologi; Marine and Brackish Water Ecology; Marine Ecology; marin ekologi; geokemi; Geochemistry;

    Abstract : Eutrophication is one of the greatest threats for the Baltic Sea, and one of its more critical consequences is bottom water hypoxia. Nutrient enrichment and oxygen-depletion affect both the deep central basins and a number of coastal areas, even though strategies for nutrient reduction have lately been implemented. READ MORE