Sökning: "lakes"

Visar resultat 21 - 25 av 381 avhandlingar innehållade ordet lakes.

  1. 21. Persistent organic pollutants in benthic foodwebs

    Författare :Niklas Holmqvist; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; limnologi; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; Intraspecific interactions; streams; nutrients; lakes; crayfish; eels; Persistent organic pollutants; Benthic foodwebs; akvatisk ekologi; Environmental chemistry; Miljökemi;

    Sammanfattning : Concentrations of persistent organic pollutants (POPs) in aquatic biota are dependent on several factors both on individual and on system level. Bioaccumulation of POPs in pelagic biota in lakes as well as fish in streams has been shown to be dependent on nutrient regime of the system. LÄS MER

  3. 22. Microbial evolution: patterns of diversity in aquatic protists

    Författare :Ramiro Logares; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dinoflagellates; biodiversity; lakes; Evolution; diversification; microbes; biogeography;

    Sammanfattning : Little is known about how microbes diversify in nature. In contrast to the more studied multicellular organisms, microbes can have a) huge population sizes, b) high reproductive rates and c) long-distance dispersal. These characteristics can affect their tempo and mode of diversification in ways that still need to be understood. LÄS MER

  4. 23. The importance of terrestrial carbon in plankton food webs

    Författare :Cesar Bolivar Daniel; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ecology; lakes; carbon; zooplankton; Spumella elongata; Poterioochromonas malhamensis; flagellates; bacteria; stable isotopes; photochemistry; autochthonous; DOC; allochthonous; plankton; Ekologi; Hydrobiology; marine biology; aquatic ecology; limnology; Marinbiologi; limnologi; akvatisk ekologi;

    Sammanfattning : Allochthonous substances, i.e. produced in terrestrial ecosystems, are known to fuel bacterial production in humic lakes. I observed that allochthonous carbon subsidizes bacteria even at high levels of phytoplankton biomass. LÄS MER

  5. 24. Dissolved organic matter in lakes : Chemical diversity and continuum of reactivity

    Författare :Alina Mostovaya; Lars Tranvik; Colin Stedmon; Uppsala universitet; []
    Nyckelord :dissolved organic matter; DOM; dissolved organic carbon; DOC; PARAFAC; reactivity continuum model; ultrahigh resolution mass spectrometry; FT-ICR-MS; organic matter characterization; decomposition kinetics; baseline metabolism; Biologi med inriktning mot limnologi; Biology with specialization in Limnology;

    Sammanfattning : Dissolved organic matter (DOM) is the largest pool of organic carbon in aquatic systems and an important component of the global carbon cycle. Large amounts of DOM are decomposed within lakes, resulting in fluxes of CO2 and CH4 to the atmosphere. LÄS MER

  7. 25. Acidification trends in Swedish lakes : an assessment of past water chemistry conditions using lake sediments

    Författare :Tom Korsman; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Palaeolimnology; acidification history; alkalization; acid deposition; land-use; lake sediments; near infrared spectroscopy; diatoms; multivariate calibration; Sweden;

    Sammanfattning : This thesis presents temporal perspectives of lake acidification in Sweden. Sediment records have been used to study timing, trends and causes of acidification, and two different techniques for assessing past lake-water acidity are presented. LÄS MER