Search for dissertations about: "diatom thesis"

Showing result 1 - 5 of 77 swedish dissertations containing the words diatom thesis.

  2. 1. Diatom-rich sediment formation in lakes

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

    Abstract : 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. READ MORE

  4. 2. Diatom and Sedimentological Investigations on West Antarctic Shelf Sediment

    Author : Charlotte Sjunneskog; Bjorg Stabell; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Antarctica; climate change; diatom abundance; geochemistry; Geovetenskap; Earth sciences; Geovetenskap; Quarternary Geology; kvartärgeologi;

    Abstract : Climate and environmental change following the retreat of the last glacial ice sheet in the Antarctic Peninsula has been interpreted, employing diatom abundance, relative abundance of Chaetoceros resting spores and diatom assemblages as proxies. These together with sedimentological data and radiocarbon dating, suggest four major events that can be further subdivided. READ MORE

  5. 3. Gradients of time and complexity : understanding how riparian and instream ecosystems recover after stream restoration

    Author : Eliza Maher Hasselquist; Christer Nilsson; Stewart Rood; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; bioassessment; biodiversity; boreal; bryophyte; chronosequence; complexity; diatom; geomorphology; habitat heterogeneity; hydromorphological; macroinvertebrate; macrophyte; nitrogen cycling; river restoration; riparian buffer; stable isotopes; succession; Sweden; Environmental Science; miljövetenskap;

    Abstract : Why evaluations of the ecological outcomes of stream and river restoration have largely reported inconclusive or negative results has been the subject of much debate over the last decade or more. Understanding the reasons behind the lack of positive results is important for bettering future restoration efforts and setting realistic expectations for restoration outcomes. READ MORE

  6. 4. Diatom silica in lake sediments and suspended matter

    Author : Elsa Peinerud; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Abstract : .... READ MORE

  7. 5. Copepods in Skeletonema-dominated food webs : Toxicity and nutritional quality as factors controlling copepod-diatom interactions

    Author : Roswati Md Amin; Ulf Båmstedt; Sigrun Jónasdóttir; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Copepod-diatom interaction; toxicity; nutritional quality; Skeletonema;

    Abstract : My thesis focuses on copepod-diatom interactions, specifically on the effects of food quality and toxicity on copepod feeding, reproductive success and behavior but as a frame, also includes a quantitative evaluation of copepod carbon requirements compared to other trophic plankton groups. My aim was to evaluate the function of copepods in diatom-dominated spring blooms. READ MORE