Sökning: "Ingemar Renberg"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Ingemar Renberg.

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

    Detta är en avhandling från Umeå : Ekologi och geovetenskap

    Författare :Christian Bigler; Ingemar Renberg; Roland Hall; N. John Anderson; [2001]
    Nyckelord :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; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; naturgeografi; Physical Geography;

    Sammanfattning : 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. LÄS MER

  2. 2. Varved lake sediments and diagenetic processes

    Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap

    Författare :Veronika Gälman; Ingemar Renberg; Daniel Conley; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; NATURAL SCIENCES Earth sciences; NATURVETENSKAP Geovetenskap;

    Sammanfattning : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. LÄS MER

  3. 3. The fate of airborne lead pollution in boreal forest soils

    Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap

    Författare :Jonatan Klaminder; Ingemar Renberg; John G. Farmer; [2005]
    Nyckelord :Air pollution; lead; lead isotopes; peat; forest soil; forest plants;

    Sammanfattning : Lead has a more than three-millennia-long pollution history in Europe. Metal production, burning of coal and use of leaded petrol resulted in a significant pollution of the atmosphere. As a consequence of atmospheric fallout, the Swedish boreal forest is strongly contaminated by airborne lead pollution. LÄS MER

  4. 4. Long-term changes of mercury, lead and persistent organic pollutants in arctic environments

    Detta är en avhandling från Umeå : Ekologi, miljö och geovetenskap

    Författare :Carola Lindeberg; Ingemar Renberg; Mats Tysklind; Ove Emteryd; Edvard Karlsson; Per Jonsson; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lake sediment; time trends; chlordane; hexachlorobenzene; mercury; lead; soil; climate changes; Arctic; Greenland; Sweden; Swedish mountains; PCB; PBDE; pesticides; NATURAL SCIENCES Earth sciences; NATURVETENSKAP Geovetenskap;

    Sammanfattning : The Arctic represents a huge area with poor infrastructure contributing to limited possibilities to establish monitoring and research programs. From the investigations that have been performed we know that the arctic environment is affected by anthropogenic emissions from lower latitudes, but knowledge about underlying transport processes, the arctic pollution extent and the rates of changes are limited. LÄS MER

  5. 5. A paleolimnological perspective on liming – implications for defining reference conditions in Swedish lakes

    Detta är en avhandling från Umeå : VMC, KBC, Umeå University

    Författare :Matilda Norberg; Ingemar Renberg; Helen Bennion; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acidification; Liming; European Water Framework Directive; Reference condition; Diatoms; Paleolimnology; Monitoring; Lake sediments; NATURAL SCIENCES Earth sciences; NATURVETENSKAP Geovetenskap; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys;

    Sammanfattning : Using paleolimnological techniques, I have studied surface-water acidification and the effects of liming in Swedish lakes on a decadal to millennial time-scale. The overall objective was to contribute to the discussion on the fulfilment of goals within the Swedish liming program. LÄS MER