Search for dissertations about: "bacillariophyceae"

Found 3 swedish dissertations containing the word bacillariophyceae.

  2. 1. Diatoms as indicators of Holocene climate and environmental change in northern Sweden

    Author : Christian Bigler; Ingemar Renberg; Roland Hall; N. John Anderson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physical geography and sedimentology; diatoms; Holocene; paleolimnology; climate change; lake sediments; transfer functions; quantitative environmental reconstructions; northern Sweden; Abisko; Naturgeografi och sedimentologi; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

    Abstract : The objective of the thesis was to explore the potential of diatoms (Bacillariophyceae) as indicators of Holocene climate and environmental change in northern Sweden (Abisko region, 68°21'N, 18°49'E). A modern surface-sediment calibration set including 100 lakes was developed and lake-water pH, sedimentary organic content (assessed by loss-on-ignition) and temperature were identified as most powerful environmental variables explaining the variance within the diatom assemblages. READ MORE

  4. 2. Genomic and morphological diversity of marine planktonic diatom-diazotroph associations : a continuum of integration and diversification through geological time

    Author : Andrea Caputo; Rachel Ann Foster; Monika Quinones Winder; Ramon Massana; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; diatoms; cyanobacteria; diazotrophs; symbiosis; evolution; phylogenetics; confocal microscopy; qPCR; CARD-FISH; tropics; sub-tropics; Marine Ecology; marin ekologi;

    Abstract : Symbioses between eukaryotes and nitrogen (N2)-fixing cyanobacteria (or diazotrophs) are quite common in the plankton community. A few genera of diatoms (Bacillariophyceae) such as Rhizosolenia, Hemiaulus and Chaetoceros are well known to form symbioses with the heterocystous diazotrophic cyanobacteria Richelia intracellularis and Calothrix rhizosoleniae. READ MORE

  5. 3. Phytoplankton in Swedish oligotrophic lakes, affected by acidification, metals and liming

    Author : Einar Hörnström; Eva Willén; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecological Botany; ekologisk botanik;

    Abstract : Anthropogenic airborne acidification has seriously affected thousands of lakes in Sweden, an alarming fact which was first noticed in the early 1970s, when pH had decreased to values below 5, especially in areas poor in limestone such as the Swedish west coast. This development was critical to phytoplankton, the diversity of which being markedly reduced, and where the groups Cyanophyceae, Bacillariophyceae and Conjugatophyceae were totally eliminated. READ MORE