Avancerad sökning

Visar resultat 1 - 5 av 7 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Isotope-based reconstruction of the biogeochemical Si cycle : Implications for climate change and human perturbation

    Författare :Xiaole Sun; Carl-Magnus Mörth; Christoph Humborg; Per Andersson; Brian Fry; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diatoms; biogenic silica BSi ; dissolved Si DSi ; Si isotope fractionation; the Baltic Sea; geokemi; Geochemistry;

    Sammanfattning : The global silicon (Si) cycle is of fundamental importance for the global carbon cycle. Diatom growth in the oceans is a major sequestration pathway for carbon on a global scale (often referred to as the biological pump). LÄS MER

  2. 2. Silicon cycling in the Baltic Sea : Trends and budget of dissolved silica

    Författare :Liana Papush; Åsa Danielsson; Lars Rahm; Petra Tallberg; Linköpings universitet; []
    Nyckelord :Dissolved silica; trends; nutrient; nutrient ratios; diatoms; Redfield; limitation; eutrophication; riverine load; budget; fluxes; accumulation; retention; optimisation; Baltic Sea; Löst kisel; trender; näringsämne; näringsämnens kvoter; kiselalger; Redfield; tillväxtbegränsning; övergödning; flodtillförsel; budget; flöden; ackumulering; retention; optimering; Östersjön; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : The dissolved silicon (DSi) has a crucial role for growth of a large group of primary producers – diatoms and, hence, impact on functioning of the aquatic food web. This thesis contributes to an increased understanding of the modifications of the DSi cycling in the Baltic Sea. LÄS MER

  3. 3. Diatom-rich sediment formation in lakes

    Författare :Petra Zahajská; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Silicon; silica; diatom; biogenic silica; lake; sediment; stable Si isotopes; Ge Si; Yellowstone; Northern Sweden;

    Sammanfattning : Unicellular photosynthetic golden algae called diatoms are one of the most abundant silicifying organisms. Diatoms take up silicon and build their frustules, in the form of biogenic silica (BSi), which have high preservation potential, and thus are found in sediments. LÄS MER

  4. 4. Integrating fluvial processes into the global Si cycle

    Författare :Patrick Frings; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Silicon (Si) is ubiqutious in natural waters as dissolved silica (DSi) and is used as a nutrient by many plant and animal species. DSi ultimately derives from the weathering of silicate minerals, a process which also consumes atmospheric CO2 and couples the silicon and carbon cycles. LÄS MER

  5. 5. Marine silicon cycle through the Cenozoic

    Författare :Guillaume Fontorbe; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Si isotopes; Paleogene; PETM; glacial-interglacial; ocean circulation;

    Sammanfattning : Silicon (Si) cycle is one of Earth's major biogeochemical cycles. Furthermore, the dissolved form of Si (DSi) is an essential nutrient for both terrestrial and marine ecosystems. LÄS MER